Weekly Propagation Forecast Bulletins, September 7, 2026

 Weekly Propagation Forecast Bulletins

:Product: Weekly Highlights and Forecasts

:Issued: 2026 Sep 07 0224 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services

#

#                Weekly Highlights and Forecasts

#

Highlights of Solar and Geomagnetic Activity

31 August - 06 September 2026

Solar activity was at moderate levels on 02 Sep and 04-05 Sep due to

three R1 (Minor) M-class flares, and low levels on the remaining

days. The largest flare of the period was an M3.0 at 02/1920 UTC

from Region 4524 (N12, L=224, class/area Cso/100 on 05 Sep), which

was also responsible for another M1.2/1n at 04/0753 UTC and 11

C-class flares throughout the period. The M3.0 was accompanied by

Type II (estimated velocity 1181 km/s) and IV radio sweeps and a CME

first observed in LASCO C2 at ~02/1936 UTC, which modeling indicated

would pass behind Earth orbit. 

The last R1 was an M1.0/1f at 05/1518 UTC from Plage Region 4520

(S12, L=337, class/area Dai/40 on 01 Sep); this region had fully

decayed to plage on 03 Sep. An associated CME first became visible

in LASCO C2 at ~ 05/1800 and in STEREO coronagraph imagery at

~05/1608 UTC as a halo. Modeling indicated this eruption would pass

ahead of Earth orbit. 

Notably, Plage Region 4518 (N07, L=354, class/area Cri/30 on 26

Aug), which had fully decayed to plage on 03 Sep as well, also

produced a C1.3 at 04/1527 UTC. 

7 additional CMEs were observed this reporting period. Coronal

dimming seen in GOES/SUVI 195 starting ~02/0910 UTC was associated

with a CME first seen in STEREO coronagraph imagery at ~02/1108 UTC;

modeling indicated that the bulk of the material is likely to pass

ahead of Earth orbit but a glancing blow on 07 Sep was possible. A

C7.9/Sn at 03/1630 UTC from Region 4524 was accompanied by a Type II

radio sweep (estimated velocity 1359 km/s) and a CME first observed

in LASCO C2 at ~03/1636 UTC, which modeling indicated would not hit

Earth. A C6.7/Sf at 04/1930 UTC from Region 4524 was accompanied by

Type II (estimated velocity 698 km/s) and IV radio sweeps and a CME

first visible in LASCO C2 at ~04/1924 UTC and STEREO at ~ 04/2030

UTC; modeling indicates this eruption may swallow the 02 Sep

eruption and produce a glancing blow at Earth either late 07 Sep or

early 08 Sep. A north-south filament just SE of disk-center began

erupting at ~05/0530 UTC, and an associated CME was first observed

in STEREO coronagraph imagery at ~05/0638 UTC. A C6.4/1n at 05/1045

UTC from Region 4524 was associated with a CME first observed in

LASCO C2 at ~ 05/1112 UTC. A C8.5/2n at 05/1746 UTC from Region 4524

was associated with a CME first observed in LASCO C2 at ~05/1800.

Modeling indicates that these three CMEs may have a merged arrival

at Earth on 08 Sep. Finally, a C5.0/1n at 06/1042 UTC from Region

4524 was associated with a CME first observed in STEREO coronagraph

imagery at ~06/1053 UTC, which modeling indicates may produce an

arrival at Earth late 08 Sep or early 09 Sep. 

Proton levels at geosynchronous orbit rapidly enhanced on 05 Sep in

response to the M1.0 from Plage Region 4520. The greater than 100

MeV proton flux crossed the 1 pfu threshold at 05/1545 UTC, peaked

at 05/1550 UTC at 1.16 pfu, and crossed back below the threshold at

05/1615 UTC. The greater than 10 MeV proton flux crossed the 10 pfu

threshold at 05/1615 UTC, peaked at 05/1645 UTC at 18 pfu, and

crossed back below the threshold at 05/2135 UTC. 

The greater than 2 MeV electron flux at geosynchronous orbit was at

high levels from 31Aug - 04 Sep and on 06 Sep, returning to normal

to moderate levels on 05 Sep. 

Geomagnetic field activity was at unsettled levels 31 Aug-01 Sep and

05 Sep, and was otherwise at quiet levels. 

Forecast of Solar and Geomagnetic Activity

07 September - 03 October 2026

Solar activity is expected to be at low levels, with a chance for

moderate levels and a slight chance for high levels throughout the

forecast period. 

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is

expected to be at high levels on 09-12 Sep, 16-23 Sep, and 27 Sep-03

Oct. Levels are expected to be at normal to moderate levels on 07-08

Sep, 13-15 Sep, and 24-26 Sep. 

Geomagnetic field activity is expected to reach active to G1 storming

levels on 07-08 Sep due to the anticipated arrivals of the CMEs

discussed above. G1 storming levels are again anticipated on 24-26

Sep due to a recurrent positive polarity coronal hole high-speed

stream (CH HSS), with active levels anticipated on 27 Sep. Active

levels are also anticipated on 14-16 Sep due to a recurrent negative

polarity CH HSS. Largely quiet levels are anticipated for all

remaining dates in the forecast period. 

Product: 27-day Space Weather Outlook Table 27DO.txt

:Issued: 2026 Sep 07 0224 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services

#

#      27-day Space Weather Outlook Table

#                Issued 2026-09-07

#

#   UTC      Radio Flux   Planetary   Largest

#  Date       10.7 cm      A Index    Kp Index

2026 Sep 07     108          16          4

2026 Sep 08     108          30          5

2026 Sep 09     107           9          3

2026 Sep 10     105           5          2

2026 Sep 11     108           5          2

2026 Sep 12     105           5          2

2026 Sep 13     102           5          2

2026 Sep 14     105          15          4

2026 Sep 15     105          12          4

2026 Sep 16     105          10          4

2026 Sep 17     105           5          2

2026 Sep 18     110           5          2

2026 Sep 19     110           5          2

2026 Sep 20     115           5          2

2026 Sep 21     115           5          2

2026 Sep 22     110           4          2

2026 Sep 23     105           4          2

2026 Sep 24     100          18          5

2026 Sep 25     105          18          5

2026 Sep 26     105          18          5

2026 Sep 27     100          15          4

2026 Sep 28     100           5          2

2026 Sep 29     105           5          2

2026 Sep 30     110           5          2

2026 Oct 01     110           5          2

2026 Oct 02     110           5          2

2026 Oct 03     110           5          2

(NOAA)

U.K. Propagation Update-August 28, 2026

 

RSGB

RadCom Assistant Editor | August 28, 2026 Compiled by G0KYA, G3YLA and G4BAO on 27 August 2026.

Last week, we said there were no coronal holes to threaten HF propagation. However, guess what appeared just after the time of writing…

Coronal holes can appear at any time, which is why we recommend going to solarham.com  for daily updates.

This week, another coronal hole has appeared and this one really does look like it could threaten Earth. This, coupled with coronal mass ejections, means that today, 30 August, could see the Kp index rise and maximum useable frequencies, or MUFs, fall.

On a brighter note, the Kp index has been very low this past week, mostly below 2, with the result that HF propagation has been very good.

Top DX being worked includes RI1FJL on Franz Josef Land in the Arctic Circle, which has been loud on many bands, right up to the 12m and 10m bands.

Other DX to be worked in the coming week includes V5/HB9BFM from Namibia; J38DX and J38LD from Grenada and P29YY working from Papua New Guinea.

A quick check of the NCDXF beacon chain revealed very good propagation on 14MHz and 21MHz. This includes reception of the following beacons: 

CS3B in Madeira; RR90 in Siberia; 4S7B in Sri Lanka; 4X6TU in Israel; 4U1UN in New York.

So it looks like we are starting to leave the summer doldrums and entering better autumnal HF conditions.

Next week, NOAA predicts that the solar flux index will be around 120, falling to 90 as the week progresses. After the potential for geomagnetic disruption this weekend, ending today 30 August, the forecast is good with a Kp index of around 2.

VHF and up propagation news:

The weather has changed to autumnal conditions, with lows bringing periods of rain or showers and quite windy conditions at times.

The coming week will turn out in similar fashion and means that we won’t be dealing with much, if any, tropo for VHF. The main weather-dependent mode will be rain scatter for GHz band operators.

The chances of aurora will need to show a Kp index above 5 to be of much interest and probably a bit higher for southern areas.

The prospects for meteor scatter are likely to be reduced to random activity which tends to give better results in the early morning hours before dawn.

Lastly, we are coming to the close of the Sporadic-E season and, with probably a week or so to play out, any openings will be few and far between.

Try checking during the main operating windows of mid-morning and late afternoon. As a back-up, consider the middle of the day since towards the edges of the season the traditional timings are less reliable.

For EME operators, Moon declination went positive again yesterday, 29 August, with increasing peak elevation and lengthening Moon windows.

Path losses are falling all week towards perigee on Sunday, 6 September. 

144MHz sky noise is low, increasing to medium by Friday, 4 September.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2026/08/28/propagation-news-30-august-2026/

(Mike Terry, UK/BDXC)

Weekly Propagation Forecast Bulletins, August 24, 2026

 Product: Weekly Highlights and Forecasts

:Issued: 2026 Aug 24 0259 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC contact www.swpc.noaa.gov/content/subscription-services

#

#                Weekly Highlights and Forecasts

#

Highlights of Solar and Geomagnetic Activity 17 - 23 August 2026

Solar activity reached moderate levels on 19, 20 and 21 Aug and was

at low levels on 17, 18, 22, and 23 Aug. Region 4513 (N04, L=50,

class/area Ekc/260 on 22 Aug) was the main contributor of M-class

flares, producing four out of the five M-flares observed. The

largest, an M8.1/Sf flare that peaked at 20/1142 UTC, had an

associated Type II radio sweep (estimated speed of 1201 km/s) and a

non-Earth-directed CME. Region 4513 also produced an M1.0 flare at

19/1824 UTC, an M1.8/Sf flare at 20/0805 UTC, and an M2.9/Sf flare

at 20/1611 UTC, as well as multiple C-class flares. Region 4507

(N04, L=197, class/area Ehi/300 on 18 Aug) added an M1.6 flare at

21/1017 UTC and multiple C-class flares as well.<o:p></o:p></span> 

Although proton levels never reached the S1 (Minor) storm threshold,

the greater than 10 MeV flux levels at geosynchronous orbit were

slightly enhanced between 3-6 pfu on 17-23 Aug. This enhancement was

likely associated with an energetic event from at or just beyond the

western limb on 21 Aug.<o:p></o:p></span> 

The greater than 2 MeV electron flux at geosynchronous orbit was at

normal to moderate levels on 17-20 and 23 Aug, and reached high

levels on 21-22 Aug. <o:p></o:p></span> 

Geomagnetic field activity was at quiet to active levels on 17 Aug,

reached G1 (Minor) storm levels on 18-19 Aug, quiet to unsettled on

20-21 Aug, and returned to quiet levels on 22-23 Aug. The elevated

conditions on 17-19 Aug were attributed to the flanking influence

from a CME that left the Sun on 14 Aug, combined with the onset of a

CIR ahead of a negative polarity CH HSS. The slightly elevated

activity continued on 20-21 Aug as influence from the negative

polarity CH HSS persisted, and then decreased by 22-23

Aug.<o:p></o:p></span> 

Forecast of Solar and Geomagnetic Activity 24 August - 19 September 2026

Solar activity is expected to be at low levels, with a chance for

M-class flares (R1/R2-Minor/Moderate) and a slight chance for

X-class (R3-Strong) flares on 24 Aug - 03 Sep, mainly attributed to

the flare activity and magnetic complexity of Region 4513. Activity

is then likely to decrease to just a slight chance for M-class

flares (R1/R2-Minor/Moderate) from 04 Sep - 19 Sep. 

There is a slight chance for a greater than 10 MeV proton event on

24 Aug - 03 Sep, mainly attributed to the magnetic complexity of

Region 4513. No proton events are expected from 04 Sep - 19 Sep. 

The greater than 2 MeV electron flux at geosynchronous orbit is

expected to be at high levels on 24-27 and 30 Aug, and then again on

16-18 Sep. Normal to moderate levels are expected on 28-29 and 31

Aug, and then from 31 Aug- 15 Sep and 19 Sep, 

Geomagnetic field activity is expected to be quiet to unsettled

throughout the entire period, with a chance for active conditions on 28

Aug, and 13-14 Sep, all attributed to coronal hole high-speed stream

influence. 

Product: 27-day Space Weather Outlook Table 27DO.txt

:Issued: 2026 Aug 24 0259 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC contact www.swpc.noaa.gov/content/subscription-services

#

#      27-day Space Weather Outlook Table

#                Issued 2026-08-24

#

#   UTC      Radio Flux   Planetary   Largest

#  Date       10.7 cm      A Index    Kp Index

2026 Aug 24     125           5          2

2026 Aug 25     120           5          2

2026 Aug 26     120           5          2

2026 Aug 27     120           5          2

2026 Aug 28     120          10          3

2026 Aug 29     120           8          3

2026 Aug 30     120           5          2

2026 Aug 31     120           5          2

2026 Sep 01    1151           5          2

2026 Sep 02     100           5          2

2026 Sep 03      95           5          2

2026 Sep 04      95           8          3

2026 Sep 05      90           8          3

2026 Sep 06      90           5          2

2026 Sep 07      95           5          2

2026 Sep 08      95           5          2

2026 Sep 09     100           5          2

2026 Sep 10     105           5          2

2026 Sep 11     105           5          2

2026 Sep 12     105           8          3

2026 Sep 13     105          15          3

2026 Sep 14     105          12          3

2026 Sep 15     110           8          3

2026 Sep 16     115           8          3

2026 Sep 17     115           5          2

2026 Sep 18     115           5          2

2026 Sep 19     115           5          2

(NOAA)

Weekly Propagation Forecast Bulletins-August 10, 2026

 Product: Weekly Highlights and Forecasts

:Issued: 2026 Aug 10 0153 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services

#

#                Weekly Highlights and Forecasts

#

Highlights of Solar and Geomagnetic Activity 03 - 09 August 2026

Solar activity was at very low to low levels throughout the period,

with no R1 (Minor) or greater events observed. Other activity three

CMEs associated with DSFs on 03 Aug, which arrived on 07 Aug, as

well as two CMEs without clear source locations on 04 Aug, which

arrived at Earth on 08 Aug. 

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at

normal to moderate levels throughout the period. 

Geomagnetic field activity reached G1-G2 (Minor-Moderate) storm

levels on 08 Aug following the arrival of CMEs that left the Sun on

04 Aug. Active conditions were observed on 03-04 Aug following the

arrival of a CME that left the Sun on 30 Jul. Quiet and quiet to

unsettled levels prevailed throughout the remainder of the period. 

Forecast of Solar and Geomagnetic Activity 10 August - 05 September 2026

Solar activity is expected to range from very low to low levels

throughout the outlook period. 

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is

expected to reach high levels on 12-16 and 22-23 Aug. Normal to

moderate levels are expected to prevail throughout the remainder of

the period. 

Geomagnetic field activity is likely to reach G1 (Minor) storm

levels on 11 Aug due to the anticipated arrival of a CME that left

the Sun on 08 Aug, and again on 19 Aug due to recurrent CH HSS

influences. Active conditions are likely on 10 and 17-18 Aug, while

quiet and quiet to unsettled conditions are likely to prevail

throughout the remainder of the outlook period. 

Product: 27-day Space Weather Outlook Table 27DO.txt

:Issued: 2026 Aug 10 0153 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact  www.swpc.noaa.gov/content/subscription-services

#

#      27-day Space Weather Outlook Table

#                Issued 2026-08-10

#

#   UTC      Radio Flux   Planetary   Largest

#  Date       10.7 cm      A Index    Kp Index

2026 Aug 10      90          12          4

2026 Aug 11      90          20          5

2026 Aug 12      92          10          3

2026 Aug 13      92           5          2

2026 Aug 14      95           5          2

2026 Aug 15      95           5          2

2026 Aug 16      95           5          2

2026 Aug 17     100          15          4

2026 Aug 18     105          12          4

2026 Aug 19     105          20          5

2026 Aug 20     105           8          3

2026 Aug 21     110           5          2

2026 Aug 22     115           5          2

2026 Aug 23     115           5          2

2026 Aug 24     115           5          2

2026 Aug 25     115           5          2

2026 Aug 26     110           5          2

2026 Aug 27     105           5          2

2026 Aug 28     105           5          2

2026 Aug 29     110           5          2

2026 Aug 30     110           5          2

2026 Aug 31     105           5          2

2026 Sep 01     105           5          2

2026 Sep 02     100           5          2

2026 Sep 03     100           5          2

2026 Sep 04      95           8          3

2026 Sep 05      95           8          3

(NOAA)

Weekly Propagation Forecast Bulletins, May 25, 2026

 Product: Weekly Highlights and Forecasts

:Issued: 2026 May 25 0601 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services

Highlights of Solar and Geomagnetic Activity 18 - 24 May 2026

Solar activity ranged from low to moderate levels. The largest flare was an M2.3 (R1-Minor) at 22/1029 UTC from Region 4436 (N18, L=333, class/area Dai/200 on 13 May). The region was also responsible for a C8.3 and C9.5 flares on 21/1814 UTC and 21/1825 UTC, respectively. This region was then responsible for the majority of the C-class activity until its rotation off the W limb on 21 May. On 23-24 May, the majority of the C-class activity occurred from Region 4446 (S13, L=141, class/area Dko/280 on 24 May). No Earth-directed CMEs were observed during the period. 

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit reached high levels on 18-24 May due to CH HSS influences. The highest flux observed was 6,667 pfu at 18/1435 UTC. 

Geomagnetic field activity ranged from quiet to active levels. Solar wind parameters began the period in a slow decline from 560 km/s as negative polarity CH HSS effects gradually diminished. At 19/0630 UTC, a small shock was observed increasing total field to 7-8 nT while solar wind speed increased to near 625 km/s before beginning to decline once again. This was likely the glancing effects from a CME that left the Sun on 16 May. Solar wind speed continued to decrease to nominal levels through 22 May. The geomagnetic field reacted with quiet to active levels on 19 May. Quiet to unsettled levels were observed on 18 May and 20-22 May. Quiet conditions occurred on 23-24 May. 

Forecast of Solar and Geomagnetic Activity 25 May - 20 June 2026

Solar activity is expected to be at low to moderate levels (R1-R2, Minor-Moderate) on 25 May through 07 Jun with the return of old Region 4432 (N14, L=081). Mostly low levels with a chance for M-class flares is expected from 08-20 Jun. 

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on 25-27 May and 12-20 Jun due to CH HSS influences. 

Geomagnetic field activity is expected to be at unsettled to active levels on 27-29 May, 04 Jun, 09 Jun, and 11-15 Jun due to recurrent CH HSS activity. G2 (Moderate) storm conditions are likely on 11 Jun

and G1 (Minor) storming on 12 Jun due to CIR/CH HSS onset. 

Product: 27-day Space Weather Outlook Table 27DO.txt

:Issued: 2026 May 25 0601 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services

#

#      27-day Space Weather Outlook Table

#                Issued 2026-05-25

#

#   UTC      Radio Flux   Planetary   Largest

#  Date       10.7 cm      A Index    Kp Index

2026 May 25     140           5          2

2026 May 26     145           8          3

2026 May 27     150          12          4

2026 May 28     140          12          4

2026 May 29     140           8          3

2026 May 30     145           5          2

2026 May 31     145           5          2

2026 Jun 01     145           5          2

2026 Jun 02     145           5          2

2026 Jun 03     150           5          2

2026 Jun 04     145          15          4

2026 Jun 05     140           5          2

2026 Jun 06     135           5          2

2026 Jun 07     135           5          2

2026 Jun 08     130           5          2

2026 Jun 09     125          12          4

2026 Jun 10     130           5          2

2026 Jun 11     130          30          6

2026 Jun 12     125          25          5

2026 Jun 13     120          12          4

2026 Jun 14     115          10          3

2026 Jun 15     115           8          3

2026 Jun 16     110           5          2

2026 Jun 17     110           5          2

2026 Jun 18     110           5          2

2026 Jun 19     115           5          2

2026 Jun 20     120           5          2

(NOAA)

Weekly Propagation Forecast Bulletins, May 18, 2026

 :Product: Weekly Highlights and Forecasts

:Issued: 2026 May 18 0431 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services

#

#                Weekly Highlights and Forecasts

#

Highlights of Solar and Geomagnetic Activity 11 - 17 May 2026

Solar activity reached moderate levels on 16 May due to four M-class flares. The largest were an M1.9/2N (R1-Minor) at 16/1612UTC from Region 4436 (N18, L=330, class/area=Dao/200 on 11 May) and a second

M1.9 flare (R1-Moderate) at 16/1742UTC from Region 4435 (N22, L=040, class/area=Dao/070 on 15 May). The 1612UTC M1.9 was associated with a Type IV radio sweep, two 10.7 cm radio bursts, and a filament

eruption that was centered at approximately N21W07, which lead to a complex CME signature in coronagraph imagery. The first front was first seen in LASCO C2 imagery at 16/1636UTC, and the second front

became visible at approximately 16/1700 UTC. Analysis and modeling of the event suggests potential for a glancing blow at Earth by mid UTC-day on 18 May, with the bulk of the material passing northward

of Earth&#39;s orbit. 

The other two M-flares, an M1.4 at 17/0339UTC and an M1.3 at 16/1629, were also from Regions 4435 and 4436, with the M1.3 following on the heels of the 16/1612UTC M1.9. The other 11 numbered

active regions on this visible disk were either quiet or only produced C-class activity during the past week. 3 Type II radio sweeps and an additional 10.7cm radio burst were observed during the

summary period, but they were not associated with any Earth-directed activity 

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at normal to moderate levels for the majority of the summary period, before increasing to high levels at 16/1740UTC. During the summary

period, the maximum value reached was 6,120 pfu at 17/1740UTC. 

Geomagnetic field activity reached G1-G2 (Minor-Moderate) geomagnetic storm levels on 15-16 May due to a negative polarity coronal hole high-speed stream becoming geoeffective late on 15 May.

Total magnetic field strength, Bt, increased all throughout 15 May, from approximately 3 nT to a peak of 17 nT at 15/1555UTC. The north-south component, Bz, rotated between +/- 11 nT, with maximum

southward deflections of approximately -13 nT. The interplanetary magnetic field had returned to background levels by the end of 16 May. A smaller positive polarity coronal hole high speed stream

became geoeffective on 13 May with a max Bt of 13 nT and maximum Bz southward deflection of -9 nT; however this only produced unsettled geomagnetic conditions and no NOAA Geomagnetic Storming thresholds

were reached. 

Forecast of Solar and Geomagnetic Activity 18 May - 13 June 2026

Solar activity is expected to be at low to moderate levels throughout the outlook period, with M-class activity (R1-R2, Minor-Moderate) ranging from a chance to likely and X-class activity (R3, Strong) ranging from a slight chance to a chance, due to the flare potential of several active regions currently on the visible disk and those both expected to return and indicated by Solar Orbiter magnetic imagery. 

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at high levels on 18 May and 21-23 May due to the influence from the current negative polarity coronal hole high-speed stream and an anticipated solar sector boundary cross on 21 May. The remaining days of the outlook period are likely to be at normal to moderate levels. 

Geomagnetic field activity is expected to reach G1 (Minor) geomagnetic storm levels over 18-19 May due to potential influences from the CME that left the Sun on 16 May, arriving in the near-Earth environment in the midst of the current high-speed stream. The remainder of the outlook period is anticipated to be at largely quiet to unsettled levels. 

:Product: 27-day Space Weather Outlook Table 27DO.txt

:Issued: 2026 May 18 0431 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services

#

#      27-day Space Weather Outlook Table

#                Issued 2026-05-18

#

#   UTC      Radio Flux   Planetary   Largest

#  Date       10.7 cm      A Index    Kp Index

2026 May 18     105          21          5

2026 May 19     110          21          5

2026 May 20     115           8          3

2026 May 21     115          10          3

2026 May 22     110           8          3

2026 May 23     112           5          2

2026 May 24     112           5          2

2026 May 25     115           5          2

2026 May 26     115           5          2

2026 May 27     115          12          4

2026 May 28     120          10          3

2026 May 29     125           8          3

2026 May 30     130           8          3

2026 May 31     135           8          3

2026 Jun 01     130           5          2

2026 Jun 02     130           5          2

2026 Jun 03     130           5          2

2026 Jun 04     125          12          4

2026 Jun 05     120           5          2

2026 Jun 06     115           5          2

2026 Jun 07     110           5          2

2026 Jun 08     105           5          2

2026 Jun 09     105          10          3

2026 Jun 10     100           5          2

2026 Jun 11      95          30          6

2026 Jun 12      95          25          5

2026 Jun 13      95          12          4

(NOAA)

Weekly Propagation Forecast Bulletins, May 11, 2026

 Product: Weekly Highlights and Forecasts

:Issued: 2026 May 11 0150 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services

#

#                Weekly Highlights and Forecasts

#

Highlights of Solar and Geomagnetic Activity  04 - 10 May 2026

Solar activity reached high levels on 10 May due to an M5.7/2b flare (R2-Moderate) at 10/1339UTC from Region 4436 (N19, L=330, class/area=Dao/beta on 10 May), the strongest of the period.

Associated with the event was a Type II radio sweep (est. 650 km/s), Tenflare (550sfu), and a CME signature first observed in coronagraph imagery at 10/1348UTC towards the NE. Analysis and modeling of the event is ongoing at the time of this writing. 

Region 4424 (N17, L=192, class/area=Eai/160 on 30 Apr) also produced an M-class event with an M1.8 flare (R1-Minor) observed at 04/0133 UTC. The other 10 numbered active regions on this visible disk were either mostly quiet or only produced C-class activity during the past week 

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at normal to moderate levels throughout the summary period. 

Geomagnetic field activity reached G2 (Moderate) geomagnetic storm levels on 04 May and G1 (Minor) levels on 05 May due to the influence of a passing CME. Total magnetic field strength only reached a peak of 11 nT during that time, but Bz rotated as far southward as -10 nT and was sustained southward from late on 04 May through midday on 05 May. Despite the influence of a positive polarity A coronal hole beginning late on 07 May, the mostly northward Bz component results in only quiet to unsettled conditions through the end of the reporting period. 

Forecast of Solar and Geomagnetic Activity 11 May - 06 June 2026

Solar activity is expected to be at low levels, with a chance for M-class activity (R1/R2-inor/Moderate), and a slight chance for X-class (R3-Strong), throughout the outlook period due to the flare potential of several active regions both currently on the visible disk and those expected to return from the Sun's  farside. 

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at high levels on 17-20 May due to the influence of a recurrent, negative polarity coronal hole. The remainder of the 

outlook period is likely to be at normal to moderate levels. 

Geomagnetic field activity is likely to reach G1 (Minor) geomagnetic storm levels over 15-17 May; active conditions are likely on 18 May, 23 May, 27 May, and 03 Jun; unsettled conditions are likely over 11 May, 13 May, 21-22 May, and 28 May - 31 May. All enhancements in geomagnetic activity are due to the anticipated influence of multiple, recurrent, coronal hole HSSs. The remainder of the outlook. The period is likely to be mostly quiet. 

Product: 27-day Space Weather Outlook Table 27DO.txt

:Issued: 2026 May 11 0150 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services

#

#      27-day Space Weather Outlook Table

#                Issued 2026-05-11

#

#   UTC      Radio Flux   Planetary   Largest

#  Date       10.7 cm      A Index    Kp Index

2026 May 11     128           8          3

2026 May 12     128           5          2

2026 May 13     122          10          3

2026 May 14     130           5          2

2026 May 15     125          25          5

2026 May 16     125          20          5

2026 May 17     120          18          5

2026 May 18     122          15          4

2026 May 19     130           5          2

2026 May 20     130           5          2

2026 May 21     130           8          3

2026 May 22     120          10          3

2026 May 23     125          12          4

2026 May 24     125           5          2

2026 May 25     125           5          2

2026 May 26     130           5          2

2026 May 27     135          12          4

2026 May 28     135          10          3

2026 May 29     130           8          3

2026 May 30     125           8          3

2026 May 31     122           8          3

2026 Jun 01     118           5          2

2026 Jun 02     115           5          2

2026 Jun 03     120           5          2

2026 Jun 04     120          12          4

2026 Jun 05     120           5          2

2026 Jun 06     120           5          2

(NOAA)

Weekly Propagation Forecast Bulletins-May 4, 2026

Product: Weekly Highlights and Forecasts

:Issued: 2026 May 04 0142 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services

#

#                Weekly Highlights and Forecasts

#

Highlights of Solar and Geomagnetic Activity 27 April - 03 May 2026

Solar activity reached moderate levels on 27 and 18 Apr due to M-class (R1-Minor) activity from Region 4425 (N05, L=162, class/area=Ekc/320 on 28 Apr) and 4420 (S18, L=246, class/area=Eki/300 on 21 Sep). Region 4420 produced the strongest flare of the period, an M1.5/Sn (R1) flare at 28/1353 UTC. The region also produced two Type II radio sweeps alongside C-class activity. The ejecta associated with the activity originated from near the NW limb and was not suspected to contain an Earth-directed component. 

The other 13 numbered active regions on the visible disk were either mostly quiet or only produced C-class X-ray activity. No other Earth-directed CMEs were identified in available coronagraph imagery. 

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was normal to moderate levels over the past seven days. 

Geomagnetic field activity reached G1 (Minor) geomagnetic storm levels on 30 Apr and active levels on 01 May due to the influence of a negative polarity CH HSS. Total magnetic field strength reached a brief peak of 14 nT on 30 Apr, with Bz reaching as far south as -12 nT. Solar wind speeds peak at just over 500 km/s early on 01 May and gradually waned over the next two days. The remainder of the period was at quiet to unsettled levels. 

Forecast of Solar and Geomagnetic Activity 04 May - 30 May 2026

Solar activity is likely to be at low levels with a chance for M-Class (R1/R2-Minor/Moderate) throughout the outlook period due to the flare potential of multiple regions on the visible disk as well as multiple complex regions due to return from the farside.  

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is likely to reach high levels on 15-20 May due to influence from a recurrent, negative polarity coronal hole. The remainder of the outlook period is expected to at normal to moderate levels. 

Geomagnetic field activity is expected to reach G1 (Minor) geomagnetic storm levels on 15-17 May; active levels are likely on 08 May, 18 May, 23 May, and 27 May; unsettled levels are likely on 04 May, 09 May, 21-22 May, and 27 May. All enhancements in geomagnetic activity are forecast in anticipation of influence fron multiple, recurrent, coronal hole HSSs. The remainder of the outlook period is expected to be at mostly quiet levels. 

:Product: 27-day Space Weather Outlook Table 27DO.txt

:Issued: 2026 May 04 0142 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web www.swpc.noaa.gov/content/subscription-services

#

#      27-day Space Weather Outlook Table

#                Issued 2026-05-04

#

#   UTC      Radio Flux   Planetary   Largest

#  Date       10.7 cm      A Index    Kp Index

2026 May 04     140           8          3

2026 May 05     140           6          2

2026 May 06     135           6          2

2026 May 07     130           6          2

2026 May 08     135          12          4

2026 May 09     130          10          3

2026 May 10     130           6          2

2026 May 11     125           5          2

2026 May 12     125           5          2

2026 May 13     120           5          2

2026 May 14     115           5          2

2026 May 15     120          25          5

2026 May 16     120          20          5

2026 May 17     125          20          5

2026 May 18     130          15          4

2026 May 19     130           5          2

2026 May 20     130           5          2

2026 May 21     130           8          3

2026 May 22     120          10          3

2026 May 23     125          12          4

2026 May 24     125           5          2

2026 May 25     125           5          2

2026 May 26     130           5          2

2026 May 27     135          12          4

2026 May 28     135          10          3

2026 May 29     130           8          3

2026 May 30     125           8          3

(NOAA)

Weekly Propagation Forecast Bulletins

 Product: Weekly Highlights and Forecasts

:Issued: 2026 Apr 27 0538 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services

#

#                Weekly Highlights and Forecasts

#

Highlights of Solar and Geomagnetic Activity 20 - 26 April 2026

Solar activity ranged from low to high levels. The strongest events of the period were an X2.4 flare (R3-Strong) at 24/0107 UTC and an X2.5/2B (R3) at 24/0813 UTC from Region 4419 (N14, L=314,

class/area=Eki/360 on 17 Apr). The X2.4 flare had an associated Tenflare and CME signature. Modeling of the CME indicated possible influence from the far periphery of the event on 26 Apr. The X2.5

flare had an associated Type II (est 1,293 km/s), Type IV, and Tenflare (570sfu) as well as a CME signature in coronagraph imagery. Modeling of this event suggested the primary bulk of the plasma was

not on the Sun-Earth line. 

Other major X-ray events included an M6.4/1F (R2-Moderate) at 24/1815 UTC from Region 4419. The resulting CME was off the Sun-Earth line. An M6.0 (R2) flare 26/2257 UTC from Region 4420

(N16, L=225, class/area=Fki/400 on 25 Apr). As associated Type II (est 834 km/s) was reported with this event as well as a 30,000sfu burst on 245MHz. No CME signature was identified in subsequent

coronagraph imagery. 

13 other M-class (R1-Minor) events were observed over the past week with many producing radio and CME signatures. However, those events that were associated with CMEs did not contain an Earth-directed component. 

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit reached high levels on 20-24 Apr and remained at normal background to moderate levels for the remainder of the report reporting period. 

Geomagnetic field activity reached G1 (Minor) storm levels on 20-21Apr due to the influence of a negative polarity CH HSS. Solar wind speeds peaked around 550 km/s and total magnetic field strength

increased to a brief peak of 10 nT on 20 Apr. The Bz component reached as far south as -8 nT during the HSS. Quiet to unsettled conditions were observed over 22-25 Apr. A negative polarity coronal

hole, with possible weak embedded influence from a CME that left the Sun on 24 Apr, caused isolated active levels on 26 Apr. Solar wind speeds remained below 500 km/s with this coronal hole. 

Forecast of Solar and Geomagnetic Activity 27 April - 23 May 2026

Solar activity is expected to reach moderate levels (R1-R2/Minor-Moderate), with a slight chance for high (R3/Strong), from 27 Apr - 04 May due to the flare potential from multiple active regions on the solar disk. The remainder of the outlook period is likely to be at low levels, with a slight chance for M-class (R1-R2). 

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on 12 Apr, 29 Apr - 05 May, 08-14 May, and 17-21 May due to the anticipated influence from multiple, recurrent, CH HSS. The remainder of the outlook period is likely to be at normal to moderate levels. 

Geomagnetic field activity is expected to reach G1 (Minor) geomagnetic storm levels on 07 May and 15-16 May. Active conditions are likely on 27 Apr, 30 Apr, 08 May, 17-18 May, and 23 May.

Unsettled conditions are likely on 29 Apr, 01 May, 03-04 May, 09 May, and 21-22 May. All enhancements in geomagnetic activity are due to the anticipated influence of multiple, recurrent, CH HSSs. The remainder of the outlook period is expected to be at mostly quiet. 

Product: 27-day Space Weather Outlook Table 27DO.txt

:Issued: 2026 Apr 27 0538 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services

#

#      27-day Space Weather Outlook Table

#                Issued 2026-04-27

#

#   UTC      Radio Flux   Planetary   Largest

#  Date       10.7 cm      A Index    Kp Index

2026 Apr 27     155          12          4

2026 Apr 28     150           7          2

2026 Apr 29     150          10          3

2026 Apr 30     152          14          4

2026 May 01     152           8          3

2026 May 02     148           5          2

2026 May 03     142           8          3

2026 May 04     140           8          3

2026 May 05     140           5          2

2026 May 06     135           5          2

2026 May 07     135          20          5

2026 May 08     135          15          4

2026 May 09     120           8          3

2026 May 10     110           5          2

2026 May 11     115           5          2

2026 May 12     115           5          2

2026 May 13     120           5          2

2026 May 14     120           5          2

2026 May 15     118          25          5

2026 May 16     130          20          5

2026 May 17     135          20          4

2026 May 18     135          15          4

2026 May 19     135           5          2

2026 May 20     140           5          2

2026 May 21     140           8          3

2026 May 22     145          10          3

2026 May 23     145          12          4

(NOAA)

Weekly Propagation Forecast Bulletins

 Product: Weekly Highlights and Forecasts

:Issued: 2026 Apr 20 0331 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact https://www.swpc.noaa.gov/content/subscription-services

#

#                Weekly Highlights and Forecasts

#

Highlights of Solar and Geomagnetic Activity 13 - 19 April 2026

Solar activity was at very low to low levels during the period. Very low levels occurred on 14, 15 and 19 Apr, while low levels were observed on 13, 16, 17, and 18 April. 

Region 4419 (N14, L=314, class/area=Eki/360 on 17 Apr) was the most active region of the period, responsible for 5 out of the 7 C-class flares observed during the week, including the largest one: a C4.1/Sf at 17/0442 UTC. The remaining 2 C-class flares of the period were: a C1.1/Sf at 13/1137 UTC from Region 4414 (N15, L=026, class/area=Dro/030 on 08 Apr) and a C1.6 at 18/0704 UTC from Region 4416 (N19, L=047, class/area=Dai/140 on 12 Apr). Coronal activity was observed during the week with some filament eruptions and few CMEs without Earth-directed components. 

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at high levels on 13-17 Apr, followed by a day at moderate levels on 18 Apr and returning to high levels on 19 Apr, with a maximum flux of 3,250 pfu observed at 15/1800 UTC. 

Geomagnetic field activity was quiet to Moderate storm levels during the period. From 13 to 17 Apr, the geomagnetic activity remained at quiet levels. On 18 Apr, the arrival of a negative polarity CH HSS influence disturbed the Geospace, elevating the activity from unsettled to Moderate storm levels. On 19 Apr, Moderate storm levels were observed during an isolated synoptic period (0600-0900 UTC) and the geomagnetic activity returned to quiet level by the end of the day as the CH HSS effects waned. 

Forecast of Solar and Geomagnetic Activity 20 April - 16 May 2026

Solar activity is expected to be at low levels, with a varying chance for M-class (R1-R2/Minor-Moderate) flares and a slight chance for X-class (R3/Strong or greater) flares through 16 May. 

No proton events are expected at geosynchronous orbit, barring any significant, non-recurrent solar activity. 

The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on 20-22 Apr, 27-28 Apr, 30 Apr-05 May, and 08-14 May. Normal to moderate electron flux levels are expected on 23-26 Apr, 29 Apr, 06-07 May, and 15-16 May. 

Geomagnetic field activity is expected to remain at quiet to active levels during most of the outlook period, with the exception of 5 days when G1 (Minor) storm levels are anticipated due to the recurrent influence of CH HSS: 29-30 Apr (-CH HSS), 07 May (+CH HSS) and 15-16 May (-CH HSS). 

Product: 27-day Space Weather Outlook Table 27DO.txt

:Issued: 2026 Apr 20 0331 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web https://www.swpc.noaa.gov/content/subscription-services

#

#      27-day Space Weather Outlook Table

#                Issued 2026-04-20

#

#   UTC      Radio Flux   Planetary   Largest

#  Date       10.7 cm      A Index    Kp Index

2026 Apr 20     105          18          4

2026 Apr 21     110          15          4

2026 Apr 22     120           8          3

2026 Apr 23     125           5          2

2026 Apr 24     120           8          3

2026 Apr 25     115           8          3

2026 Apr 26     120           5          2

2026 Apr 27     125           5          2

2026 Apr 28     125           5          2

2026 Apr 29     125          20          5

2026 Apr 30     125          18          5

2026 May 01     125          12          4

2026 May 02     125          10          4

2026 May 03     115           8          3

2026 May 04     108           8          3

2026 May 05     105           5          2

2026 May 06     100           5          2

2026 May 07      95          20          5

2026 May 08      90          15          4

2026 May 09      90           8          3

2026 May 10      95           5          2

2026 May 11     100           5          2

2026 May 12     105           5          2

2026 May 13     110           5          2

2026 May 14     110           5          2

2026 May 15     105          25          5

2026 May 16     105          20          5

(NOAA)

Weekly Propagation Forecast Bulletins

 :Product: Weekly Highlights and Forecasts

:Issued: 2026 Apr 13 0104 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact  www.swpc.noaa.gov/content/subscription-services

#

#                Weekly Highlights and Forecasts

#

Highlights of Solar and Geomagnetic Activity 06 - 12 April 2026

Solar activity was at very low to moderate levels during the period. Moderate levels were reached on 09 Apr, with low levels observed on 06-08 Apr and 11-12 Apr. Very low levels occurred on 10 Apr. 

Region 4409 (N02, L=158, class/area=Eai/190 on 07 Apr) was the most active region of the period, producing 11 C-class flares and the only M-class flare of the period, an impulsive M1.0/Sf at 09/0845

UTC. Region 4417 (S08, L=123, class/area=Dao/30 on 12 Apr) also contributed notable activity with 7 C-class flares after appearing quickly on 11 Apr near the West limb. Other activity included a

C8.7/Sf flare from Region 4414 (N15, L=26, class/area Dro/30 on 08 Apr) at 08/1543 UTC, which was associated with Type III radio emissions and a weak CME without any Earth-directed components. 

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at high levels throughout the reporting period. Flux levels reached a peak value of 10,679 pfu at 09/1605 UTC. 

Geomagnetic field activity ranged from quiet to active levels during the period. The beginning of the period (06-07 Apr) saw quiet to unsettled conditions as the influence of a negative polarity coronal

hole high speed stream (-CH HSS) continued to wane. From 10-12 Apr, quiet to active levels were observed under the onset and influence of a positive polarity CH HSS (+CH HSS). Quiet conditions prevailed

during all other days of the period under a nominal solar wind regime. 

Forecast of Solar and Geomagnetic Activity 13 April - 09 May 2026

Solar activity is expected to be at low levels, with a varying chance for M-class (R1-R2/Minor-Moderate) flares and a slight chance for X-class (R3/Strong or greater) flares through 09 May. 

No proton events are expected at geosynchronous orbit, barring any significant, non-recurrent solar activity. 

The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on 13-17 Apr, 19-24 Apr, 26-28 Apr, 30 Apr-05 May, and 08-09 May. Normal to moderate flux levels are

expected on 18 Apr, 25 Apr, 29 Apr, and 06-07 May. 

Geomagnetic field activity is anticipated to reach G1-G2 (Minor-Moderate) storm levels on 19 Apr and 29 Apr due to -CH HSS influences, and on 07 May due to +CH HSS influences. Active

conditions are expected on 18 Apr, 20 Apr, and 30 Apr-01 May in response to -CH HSS effects, and on 15 Apr, 25 Apr, and 08 May due to +CH HSS effects. Mostly quiet to unsettled conditions are

expected for all other days of the period. 

Product: 27-day Space Weather Outlook Table 27DO.txt

:Issued: 2026 Apr 13 0104 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services

#

#      27-day Space Weather Outlook Table

#                Issued 2026-04-13

#

#   UTC      Radio Flux   Planetary   Largest

#  Date       10.7 cm      A Index    Kp Index

2026 Apr 13      95           8          3

2026 Apr 14      90           8          3

2026 Apr 15     100          12          3

2026 Apr 16     105           8          3

2026 Apr 17     110           5          2

2026 Apr 18     110          15          3

2026 Apr 19     110          20          4

2026 Apr 20     120          12          4

2026 Apr 21     130          10          3

2026 Apr 22     140           8          3

2026 Apr 23     145           5          2

2026 Apr 24     145           8          3

2026 Apr 25     140          12          4

2026 Apr 26     140          10          3

2026 Apr 27     140           5          2

2026 Apr 28     140           5          2

2026 Apr 29     135          20          5

2026 Apr 30     130          18          5

2026 May 01     125          12          4

2026 May 02     125          10          3

2026 May 03     115           8          3

2026 May 04     108           8          3

2026 May 05     105           5          2

2026 May 06     100           5          2

2026 May 07      95          20          4

2026 May 08      90          15          3

2026 May 09      90           8          3

(NOAA)

Weekly Propagation Forecast Bulletins

 Product: Weekly Highlights and Forecasts

:Issued: 2026 Apr 06 0211 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services

#

#                Weekly Highlights and Forecasts

#

Highlights of Solar and Geomagnetic Activity 30 March - 05 April 2026

Solar activity reached high levels on 30 Mar and 04 Apr, moderate levels on 02-03 Apr, with low levels observed on 31 Mar, 01 Apr, and 5 Apr. 

Region 4409 (N02, L=156, class/area=Eai/170 on 04 Apr) was the most active of the period, producing 50 C-class flares and six M-class flares. Region 4405 (S27, L=220, class/area=Eai/220 on 02 Apr) added the strongest flare of the period, an X1.4/Sf flare, on 30 Mar at

0319 UTC. Accompanying the flare was a Type II radio sweep (estimated velocity 1872 km/s) and a partial halo CME first seen in LASCO C2 imagery at 30/0312 UTC. Expected impacts from this CME were on 01 Apr. Region 4409 also produced a C8.1 flare at 01/1958 UTC.

Accompanying this flare was a filament eruption and subsequent CME that had a likely Earth-directed trajectory with impacts likely felt on 03-04 Apr. 

Slightly elevated proton levels were observed from 01-05 Apr, but conditions remained below alert thresholds throughout the period.   The greater than 2 MeV electron flux at geosynchronous orbit reached high levels throughout most of the period of 30 Mar - 05 Apr, with a

peak flux value of 6,000 pfu observed at 05/1645 UTC. The only exception was on 02 Apr when conditions dropped to moderate levels for that 24-hour reporting period. 

Geomagnetic field activity ranged from quiet to G3 (Strong) storm levels during the 30 Mar - 05 Apr period. Quiet to unsettled levels were observed on 30 Mar - 01 Apr, and most of 05 Apr (aside from an isolated active period at the beginning of the UT day). Conditions

increased to active to G2 (Moderate) levels on 02 Apr following the onset of a negative polarity coronal hole high speed stream (CH HSS). Conditions remained at active to G1 (Minor) levels through midday on 03 Apr, when they increased to G3 (Strong) levels with the

arrival of the anticipated CME from 01 Apr (C8.1 flare and filament eruption). Conditions then decreased to G1 levels to start 04 Apr, before decreasing to quiet to active conditions lasting through 05 Apr. 

Forecast of Solar and Geomagnetic Activity 06 April - 02 May 2026

Solar activity is expected to be at low levels, with a varying chance for M-class (R1-R2/Minor-Moderate) flares, and a slight chance for X-Class (R3/Strong) flares from 06 Apr through 02 May. 

No proton events are expected at geosynchronous orbit, barring any significant, non-recurrent solar activity. 

The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on 06-09 Apr, 11-16 Apr, and 18 Apr-02 May. Normal to moderate flux levels are expected on 10 and 17 Apr. 

Geomagnetic field activity is anticipated to reach G1/G2 (Minor/Moderate) geomagnetic storm levels on 18-19, and 29 Apr due to the influence of negative polarity CH HSS (-CH HSS). Periods of G1 (Minor) storming are likely on 04 April in response to a negative

polarity CH HSS (-CH HSS). Unsettled to Active levels are expected on 06-07 Apr, 20-22 Apr, and 30 Apr, as well as 01-02 May associated with negative polarity CH HSS effects. On 10-13 and 25-26 April, positive polarity CH HSS influences are expected to bump geomagnetic

conditions to unsettled to active levels. Mostly quiet levels are expected during all other days of the period. 

Product: 27-day Space Weather Outlook Table 27DO.txt

:Issued: 2026 Apr 06 0211 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services

#

#      27-day Space Weather Outlook Table

#                Issued 2026-04-06

#

#   UTC      Radio Flux   Planetary   Largest

#  Date       10.7 cm      A Index    Kp Index

2026 Apr 06     118          10          3

2026 Apr 07     115           8          3

2026 Apr 08     113           5          2

2026 Apr 09     111           5          2

2026 Apr 10     108          12          4

2026 Apr 11     106          18          5

2026 Apr 12     105          10          4

2026 Apr 13     108           8          3

2026 Apr 14     110           7          2

2026 Apr 15     115           5          2

2026 Apr 16     115           4          2

2026 Apr 17     120           7          2

2026 Apr 18     122          48          6

2026 Apr 19     124          22          5

2026 Apr 20     130          12          4

2026 Apr 21     140          12          4

2026 Apr 22     150           8          3

2026 Apr 23     155           5          2

2026 Apr 24     160           8          3

2026 Apr 25     155          12          4

2026 Apr 26     150          10          3

2026 Apr 27     145           5          2

2026 Apr 28     140           5          2

2026 Apr 29     140          20          5

2026 Apr 30     135          18          5

2026 May 01     130          12          4

2026 May 02     120           8          3

(NOAA)