:Product: 1017RSGA.txt
:Issued: 2026 Oct 17 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 290 Issued at 2200Z on 17 Oct 2026

IA.  Analysis of Solar Active Regions and Activity from 16/2100Z to
17/2100Z: Solar activity has been at low levels for the past 24 hours.
There are currently 3 numbered sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be low with
a slight chance for an M-class flare on days one, two, and three (18
Oct, 19 Oct, 20 Oct).

IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 771 km/s at 16/2359Z. Total IMF reached 8
nT at 17/1451Z. The maximum southward component of Bz reached -7 nT at
17/1742Z. Electrons greater than 2 MeV at geosynchronous orbit reached a
peak level of 818 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on day one (18 Oct), quiet to active levels on day
two (19 Oct) and quiet to minor storm levels on day three (20 Oct).

III.  Event probabilities 18 Oct-20 Oct
Class M    20/20/20
Class X    05/05/05
Proton     05/05/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           17 Oct 132
Predicted   18 Oct-20 Oct 130/125/125
90 Day Mean        17 Oct 117

V.  Geomagnetic A Indices
Observed Afr/Ap 16 Oct  010/012
Estimated Afr/Ap 17 Oct  005/006
Predicted Afr/Ap 18 Oct-20 Oct  006/005-009/012-018/022

VI.  Geomagnetic Activity Probabilities 18 Oct-20 Oct
A.  Middle Latitudes
Active                10/20/40
Minor Storm           05/05/20
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           15/20/20
Major-severe storm    15/25/30