:Product: Report of Solar-Geophysical Activity
:Issued: 2024 May 11 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 132 Issued at 2200Z on 11 May 2024

IA.  Analysis of Solar Active Regions and Activity from 10/2100Z to
11/2100Z: Solar activity has been at high levels for the past 24 hours.
The largest solar event of the period was a X5 event observed at
11/0123Z from Region 3664 (S18W62). There are currently 8 numbered
sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be high on
days one, two, and three (12 May, 13 May, 14 May).

IIA.  Geophysical Activity Summary 10/2100Z to 11/2100Z: The geomagnetic
field has been at severe storm levels for the past 24 hours. Solar wind
speed reached a peak of 993 km/s at 11/1433Z. Total IMF reached 73 nT at
10/2305Z. The maximum southward component of Bz reached -50 nT at
11/0048Z.  Protons greater than 10 MeV at geosynchronous orbit reached a
peak level of 116 pfu at 11/0910Z. Protons greater than 100 MeV at
geosynchronous orbit reached a peak level of 7 pfu at 11/0715Z.
Electrons greater than 2 MeV at geosynchronous orbit reached a peak
level of 119 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at severe storm levels on day one (12 May), active to severe storm
levels on day two (13 May) and unsettled to minor storm levels on day
three (14 May). Protons are expected to cross threshold on days one and
two (12 May, 13 May) and are likely to cross threshold on day three (14
May).

III.  Event probabilities 12 May-14 May
Class M    95/95/95
Class X    75/75/75
Proton     99/99/60
PCAF       red

IV.  Penticton 10.7 cm Flux
Observed           11 May 214
Predicted   12 May-14 May 220/220/215
90 Day Mean        11 May 165

V.  Geomagnetic A Indices
Observed Afr/Ap 10 May  080/157
Estimated Afr/Ap 11 May  268/317
Predicted Afr/Ap 12 May-14 May  114/156-041/060-015/020

VI.  Geomagnetic Activity Probabilities 12 May-14 May
A.  Middle Latitudes
Active                05/15/35
Minor Storm           40/35/30
Major-severe storm    55/55/15
B.  High Latitudes
Active                01/01/05
Minor Storm           05/05/20
Major-severe storm    95/95/70