:Product: Report of Solar-Geophysical Activity
:Issued: 2026 Jul 28 2200 UTC
# Prepared jointly by the U.S. Dept. of Commerce, NOAA,
# Space Weather Prediction Center and the U.S. Air Force.
#
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 209 Issued at 2200Z on 28 Jul 2026

IA.  Analysis of Solar Active Regions and Activity from 27/2100Z to
28/2100Z: Solar activity has been at low levels for the past 24 hours.
There are currently 7 numbered sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be low with
a chance for M-class flares on days one, two, and three (29 Jul, 30 Jul,
31 Jul).

IIA.  Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 407 km/s at 28/2050z. Total IMF reached 8
nT at 28/0806Z. The maximum southward component of Bz reached -6 nT at
27/2221Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 863 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on day one (29 Jul) and quiet to
active levels on days two and three (30 Jul, 31 Jul).

III.  Event probabilities 29 Jul-31 Jul
Class M    30/30/25
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           28 Jul 143
Predicted   29 Jul-31 Jul 145/145/140
90 Day Mean        28 Jul 133

V.  Geomagnetic A Indices
Observed Afr/Ap 27 Jul  007/007
Estimated Afr/Ap 28 Jul  008/009
Predicted Afr/Ap 29 Jul-31 Jul  007/008-010/012-014/015

VI.  Geomagnetic Activity Probabilities 29 Jul-31 Jul
A.  Middle Latitudes
Active                20/35/35
Minor Storm           05/10/15
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/10
Minor Storm           30/30/25
Major-severe storm    25/45/50