:Product: 0419RSGA.txt
:Issued: 2021 Apr 19 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 109 Issued at 2200Z on 19 Apr 2021

IA.  Analysis of Solar Active Regions and Activity from 18/2100Z to
19/2100Z: Solar activity has been at very low levels for the past 24
hours. There are currently 2 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 (20 Apr,
21 Apr, 22 Apr).

IIA.  Geophysical Activity Summary 18/2100Z to 19/2100Z: The geomagnetic
field has been at unsettled to active levels for the past 24 hours.
Solar wind speed reached a peak of 689 km/s at 19/1639Z. Total IMF
reached 6 nT at 19/0013Z. The maximum southward component of Bz reached
-6 nT at 19/0255Z.  Electrons greater than 2 MeV at geosynchronous orbit
reached a peak level of 10148 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (20 Apr) and quiet levels on
days two and three (21 Apr, 22 Apr).

III.  Event probabilities 20 Apr-22 Apr
Class M    05/05/05
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           19 Apr 086
Predicted   20 Apr-22 Apr 085/085/085
90 Day Mean        19 Apr 076

V.  Geomagnetic A Indices
Observed Afr/Ap 18 Apr  013/016
Estimated Afr/Ap 19 Apr  011/014
Predicted Afr/Ap 20 Apr-22 Apr  009/008-006/005-005/005

VI.  Geomagnetic Activity Probabilities 20 Apr-22 Apr
A.  Middle Latitudes
Active                30/15/15
Minor Storm           10/01/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           30/20/20
Major-severe storm    40/20/20