:Product: 0917RSGA.txt
:Issued: 2021 Sep 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 260 Issued at 2200Z on 17 Sep 2021

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.
The largest solar event of the period was a C3 event observed at
17/0420Z. There are currently 0 numbered sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be very low
with a chance for a C-class flares on days one, two, and three (18 Sep,
19 Sep, 20 Sep).

IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic
field has been at quiet to minor storm levels for the past 24 hours.
Solar wind speed reached a peak of 421 km/s at 17/2055Z. Total IMF
reached 14 nT at 17/1748Z. The maximum southward component of Bz reached
-13 nT at 17/1812Z.  Electrons greater than 2 MeV at geosynchronous
orbit reached a peak level of 294 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to minor storm levels on day one (18 Sep), quiet to
unsettled levels on day two (19 Sep) and quiet levels on day three (20
Sep).

III.  Event probabilities 18 Sep-20 Sep
Class M    05/05/05
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           17 Sep 073
Predicted   18 Sep-20 Sep 075/078/080
90 Day Mean        17 Sep 082

V.  Geomagnetic A Indices
Observed Afr/Ap 16 Sep  003/004
Estimated Afr/Ap 17 Sep  012/020
Predicted Afr/Ap 18 Sep-20 Sep  014/015-008/010-006/005

VI.  Geomagnetic Activity Probabilities 18 Sep-20 Sep
A.  Middle Latitudes
Active                40/30/10
Minor Storm           25/10/01
Major-severe storm    05/01/01
B.  High Latitudes
Active                10/15/15
Minor Storm           25/30/20
Major-severe storm    60/40/20