:Product: 0518RSGA.txt
:Issued: 2025 May 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 138 Issued at 2200Z on 18 May 2025

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.
There are currently 4 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 (19 May, 20 May,
21 May).

IIA.  Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic
field has been at quiet to minor storm levels for the past 24 hours.
Solar wind speed reached a peak of 950 km/s at 18/0732Z. Total IMF
reached 12 nT at 18/0951Z. The maximum southward component of Bz reached
-8 nT at 18/1510Z.  Electrons greater than 2 MeV at geosynchronous orbit
reached a peak level of 1128 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at unsettled to minor storm levels on day one (19 May) and quiet
to active levels on days two and three (20 May, 21 May).

III.  Event probabilities 19 May-21 May
Class M    25/25/25
Class X    05/05/05
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           18 May 118
Predicted   19 May-21 May 120/118/118
90 Day Mean        18 May 161

V.  Geomagnetic A Indices
Observed Afr/Ap 17 May  025/038
Estimated Afr/Ap 18 May  017/023
Predicted Afr/Ap 19 May-21 May  013/018-011/012-009/012

VI.  Geomagnetic Activity Probabilities 19 May-21 May
A.  Middle Latitudes
Active                40/30/30
Minor Storm           30/15/15
Major-severe storm    10/01/01
B.  High Latitudes
Active                10/15/15
Minor Storm           25/30/30
Major-severe storm    65/45/45
