Weekly Propagation Forecast Bulletins

 Product: Weekly Highlights and Forecasts

:Issued: 2025 May 12 0245 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

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#                Weekly Highlights and Forecasts

#

Highlights of Solar and Geomagnetic Activity 05 - 11 May 2025

Solar activity reached moderate levels in the final minutes of 11 May following an M-class event that peaked after the turn of the UT day. Solar activty was low the remainder of the time (05-10 May) leading up to that event. Region 4079 (N08, L=240, class/area=Ekc/1250 on 06 May) was responsible for what ended up being an M1.9 flare that peaked at 12/0001 UTC. This region was also responsible for 54 C-class events during the week, most of which were sub C5 level. Region 4082 (S11, L=180, class/area=Dac/140 on 06 May) contributed a pair of C7.0 flares at 08/1141 and 08/1500 UTC respectively, as well as several other low level C-class flares. No significant Earth-directed CMEs were noted during the period. 

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at high levels on 06-09 May, and moderate levels on 10-11 May. 

Geomagnetic field activity was at quiet to unsettled levels on 07 May, quiet to active levels on 06 and 08-10 May, and active to minor storm levels on 05 and 11 May. The increased activity was likely associated with negative polarity CH HSS influence. 

Forecast of Solar and Geomagnetic Activity 12 May - 07 June 2025

Solar activity is expected to be predominantly low through the outlook period, with varying chances for M-class flare activity. 

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at moderate levels from 06-28 May and again on 06-07 Jun. High levels are expected from 29 May to 05 Jun as CH HSS influences increase during this time. 

Geomagnetic field activity is anticipated to reach minor storm levels on 28 May - 01 Jun under negative polarity CH HSS influences. Active levels are likely on 13 May, and again on 02 Jun and 06 Jun. Mostly unsettled levels are likely on 12, 14, and 18-21 May, as well as 02 and 05 Jun. Quiet levels are expected on 15-17, and 22-26 May. 

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

:Issued: 2025 May 12 0245 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 2025-05-12

#

#   UTC      Radio Flux   Planetary   Largest

#  Date       10.7 cm      A Index    Kp Index

2025 May 12     125           8          5

2025 May 13     120          12          4

2025 May 14     120          10          3

2025 May 15     115           5          2

2025 May 16     115           5          2

2025 May 17     115           5          2

2025 May 18     115           8          3

2025 May 19     120          10          4

2025 May 20     125           8          3

2025 May 21     125           8          3

2025 May 22     125           6          2

2025 May 23     130           6          2

2025 May 24     130           6          2

2025 May 25     130           5          2

2025 May 26     135           5          2

2025 May 27     140           8          3

2025 May 28     140          25          5

2025 May 29     140          30          5

2025 May 30     140          20          5

2025 May 31     140          20          5

2025 Jun 01     145          20          5

2025 Jun 02     145          12          4

2025 Jun 03     145           8          3

2025 Jun 04     145          10          4

2025 Jun 05     140          12          4

2025 Jun 06     130          10          4

2025 Jun 07     125          10          4

(NOAA)

Weekly Propagation Forecast Bulletins

Product: Weekly Highlights and Forecasts
:Issued: 2008 Sep 23 2251 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact:
# http://www.swpc.noaa.gov/weekly.html
#
# Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity
15 - 21 September 2008

Solar activity was very low. No flares were detected. The visible disk was spotless.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit reached high levels during 16 - 17 September.

Geomagnetic field activity ranged from quiet to active levels during 15 - 16 September with minor to major storm periods observed at high latitudes. Activity decreased to quiet to unsettled levels during 17 - 18 September, though active to major storm periods were observed at high latitudes on 18 September. Activity decreased to mostly quiet levels during 19 - 21 September. ACE solar wind data indicated a co-rotating interaction region (CIR) was in progress at the start of the period. The CIR, which preceded a recurrent coronal hole high-speed stream (HSS), commenced on 14 September and continued into 15 September. The HSS began on 15 September and reached a peak velocity of 620 km/sec at 15/1200 UTC. Velocities gradually decreased during the remainder of the period with a minimum of 295 km/sec observed at 21/2221 UTC. The proton density increase associated with the CIR reached a peak of 17 p/cc at 15/0426 UTC.

Interplanetary magnetic field (IMF) activity associated with the CIR included increased Bt (peak 14 nT at 15/0627 UTC) and intermittent periods of southward Bz (minimum -10 nT at 15/0938 UTC). Bz settled into a range of + 5 to -5 nT following the CIR. Bt varied from 01 -
07 nT following the CIR.

Forecast of Solar and Geomagnetic Activity
24 September - 20 October 2008

Solar activity is expected to be very low.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels during 01 - 14 October.

Quiet geomagnetic conditions are expected during 24 - 29 September. Activity is expected to increase to unsettled levels on 30 September. A further increase to active to minor storm levels is expected during 01 October with a chance for major storm levels due to a recurrent coronal hole high-speed stream (HSS). Activity is expected to decrease to unsettled levels during 02 - 05 October as the HSS subsides. Quiet conditions are expected during 06 - 11 October. Activity is expected to increase to active levels on 12 October due to a recurrent coronal hole HSS. Activity is expected to decrease to quiet levels during the remainder of the period as the HSS subsides.

Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2008 Sep 23 2252 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact:
# http://www.swpc.noaa.gov/wwire.html
#
# 27-day Space Weather Outlook Table
# Issued 2008 Sep 23
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2008 Sep 24 70 5 2
2008 Sep 25 70 5 2
2008 Sep 26 70 5 2
2008 Sep 27 68 5 2
2008 Sep 28 68 5 2
2008 Sep 29 68 5 2
2008 Sep 30 67 8 3
2008 Oct 01 67 30 5
2008 Oct 02 67 8 3
2008 Oct 03 67 8 3
2008 Oct 04 67 8 3
2008 Oct 05 67 8 3
2008 Oct 06 67 5 2
2008 Oct 07 67 5 2
2008 Oct 08 67 5 2
2008 Oct 09 67 5 2
2008 Oct 10 68 5 2
2008 Oct 11 70 5 2
2008 Oct 12 70 15 4
2008 Oct 13 70 5 2
2008 Oct 14 70 5 2
2008 Oct 15 70 5 2
2008 Oct 16 70 5 2
2008 Oct 17 70 5 2
2008 Oct 18 70 5 2
2008 Oct 19 70 5 2
2008 Oct 20 70 5 2
(NOAA)