:Product: 0918RSGA.txt
:Issued: 2024 Sep 18 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 262 Issued at 2200Z on 18 Sep 2024

IA.  Analysis of Solar Active Regions and Activity from 17/2100Z to
18/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C4 event observed at
18/0344Z from Region 3828 (S13E47). There are currently 6 numbered
sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is likely to be moderate
with a slight chance for an X-class flare on days one, two, and three
(19 Sep, 20 Sep, 21 Sep).

IIA.  Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic
field has been at quiet to active levels for the past 24 hours. Solar
wind speed reached a peak of 546 km/s at 17/2326Z. Total IMF reached 9
nT at 17/2148Z. The maximum southward component of Bz reached -6 nT at
18/1055Z.  Protons greater than 10 MeV at geosynchronous orbit reached a
peak level of 6 pfu at 17/2150Z. Electrons greater than 2 MeV at
geosynchronous orbit reached a peak level of 268 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on days one and three (19 Sep, 21
Sep) and quiet levels on day two (20 Sep). Protons have a slight chance
of crossing threshold on days one, two, and three (19 Sep, 20 Sep, 21
Sep).

III.  Event probabilities 19 Sep-21 Sep
Class M    55/55/55
Class X    10/10/10
Proton     10/10/10
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           18 Sep 163
Predicted   19 Sep-21 Sep 162/155/155
90 Day Mean        18 Sep 216

V.  Geomagnetic A Indices
Observed Afr/Ap 17 Sep  039/064
Estimated Afr/Ap 18 Sep  009/010
Predicted Afr/Ap 19 Sep-21 Sep  007/008-005/005-009/010

VI.  Geomagnetic Activity Probabilities 19 Sep-21 Sep
A.  Middle Latitudes
Active                20/10/20
Minor Storm           05/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           20/15/25
Major-severe storm    25/15/30