Joint USAF/NOAA Report of Solar and Geophysical Activity 20 May 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 May 20 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 Report of Solar and Geophysical Activity
SDF Number 140 Issued at 2200Z on 20 May 2011
IA. Analysis of Solar Active Regions and Activity from 19/2100Z
to 20/2100Z: Solar activity was very low. The three spotted regions
on the disk, 1214 (S24W70), 1216 (S16E19) and 1218 (S16E40) were all
unipolar and magnetically simple.
IB. Solar Activity Forecast: Solar activity is expected to remain
very low to low. A slight chance for a C-class x-ray flare remains
for the next three days (21 May – 23 May).
IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z:
The geomagnetic field was quiet. A weak sudden impulse (3nT) at the
Boulder magnetometer was observed at 20/0415Z.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to remain predominantly quiet for the next three days (21
May – 23 May).
III. Event Probabilities 21 May-23 May
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 20 May 084
Predicted 21 May-23 May 083/080/080
90 Day Mean 20 May 108
V. Geomagnetic A Indices
Observed Afr/Ap 19 May 002/004
Estimated Afr/Ap 20 May 005/005
Predicted Afr/Ap 21 May-23 May 005/005-005/005-005/005
VI. Geomagnetic Activity Probabilities 21 May-23 May
A. Middle Latitudes
Active 10/10/05
Minor storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/10
Minor storm 05/05/05
Major-severe storm 01/01/01