:Product: 0517RSGA.txt
:Issued: 2023 May 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 137 Issued at 2200Z on 17 May 2023

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 C7 event observed at
17/1628Z. 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 (18 May, 19 May,
20 May).

IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed
reached a peak of 488 km/s at 16/2101Z. Total IMF reached 6 nT at
16/2105Z. The maximum southward component of Bz reached -3 nT at
17/0016Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 162 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on days one and two (18 May, 19 May) and quiet to
unsettled levels on day three (20 May).

III.  Event probabilities 18 May-20 May
Class M    25/25/25
Class X    05/05/05
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           17 May 138
Predicted   18 May-20 May 140/138/135
90 Day Mean        17 May 155

V.  Geomagnetic A Indices
Observed Afr/Ap 16 May  010/009
Estimated Afr/Ap 17 May  004/005
Predicted Afr/Ap 18 May-20 May  006/005-006/005-008/008

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