Monday, July 27, 2026

Weekly Propagation Forecast Bulletins

 :Product: Weekly Highlights and Forecasts
:Issued: 2026 Jul 27 0325 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 July 2026



Solar activity was at low to R1 (Minor) levels this period. A total
of 54 C-class and 6 R1 (Minor) events were observed. The largest,
and most complex spot group, was Region 4493 (N06, L=158, class/area
Eki/440 on 23 Jul). This region produced a total of 42 C-class and 5
M-class events, the largest an M3.6 at 22/0635 UTC. A 200 sfu 10 cm
Burst was associated with this event. Region 4494 (S04, L=088,
class/area Dac/120 on 26 Jul) produced the other R1 (Minor) event,
an M3.2 at 26/1528 UTC. Associated with this event was a Type II
Sweep with an estimated shock velocity of 1,057 km/s. No other
significant activity was observed. 

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at
high levels on 20 and 26 Jul with the high value of 1,300 pfu
observed at 20/1645 UTC. 

Geomagnetic field activity was at quiet to G1 (Minor) levels. Quiet
levels were observed on 20 Jul. Levels increased to unsettled to
active on 21 Jul to early on 24 Jul, with isolated G1 (Minor) levels
observed late on 23 Jul. This activity was due to effects from a
negative polarity CH HSS. Quiet conditions were observed most of 24
Jul and 25-26 Jul. 

Forecast of Solar and Geomagnetic Activity
27 July - 22 August 2026

Solar activity is expected to be at mostly low levels with a chance
for moderate R1 (Minor) 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 27 Jul, 02-03 Aug, 06-09 Aug, 12-16
Aug, and 22 Aug. The remainder of the outlook period is expected to
be at normal to moderate levels. 

Geomagnetic field activity is expected to be at unsettled to active
levels on 27-28 Jul due to potential weak CME effects. Unsettled to
active levels are expected on 29-31 Jul, 04-07 Aug, 11-12 Aug, and
17-20 Aug with isolated G1 (Minor) levels possible on 19 Aug. This
level of activity is due to recurrent CH HSS effects. Mostly quiet
levels are expected for the remainder of the outlook period. 

Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2026 Jul 27 0325 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 2026-07-27
#
#   UTC      Radio Flux   Planetary   Largest
#  Date       10.7 cm      A Index    Kp Index
2026 Jul 27     150          18          4
2026 Jul 28     150          15          3
2026 Jul 29     145           8          3
2026 Jul 30     140           8          3
2026 Jul 31     135           8          3
2026 Aug 01     130           5          2
2026 Aug 02     125           5          2
2026 Aug 03     125           5          2
2026 Aug 04     125          12          4
2026 Aug 05     120          15          3
2026 Aug 06     125          10          3
2026 Aug 07     130           7          2
2026 Aug 08     130           5          2
2026 Aug 09     130           5          2
2026 Aug 10     135           5          2
2026 Aug 11     130           8          3
2026 Aug 12     125           8          3
2026 Aug 13     125           5          2
2026 Aug 14     130           5          2
2026 Aug 15     135           5          2
2026 Aug 16     135           4          2
2026 Aug 17     135          14          3
2026 Aug 18     140          12          3
2026 Aug 19     135          22          5
2026 Aug 20     135           8          3
2026 Aug 21     130           5          2
2026 Aug 22     130           5          2
(NOAA)