Joint USAF/NOAA Report of Solar and Geophysical Activity 25 May 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 May 25 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 145 Issued at 2200Z on 25 May 2011
IA. Analysis of Solar Active Regions and Activity from 24/2100Z
to 25/2100Z: Solar activity was very low. Only low level B-class
events were observed during the period. Region 1220 (N12, L=249)
produced a long duration B2 event at 24/2237Z prior to its rotation
around the west limb. Region 1218 (S16W28) also produced B-class
events with frequent point brightenings within the region. This
region remains a spotless plage. A nine degree filament located at
N44E37 disappeared between 25/0801-1256Z. A further analysis of
this event will be performed as image data updates for any
associated CME activity. New Region 1222 (N15W24) was numbered
today.
IB. Solar Activity Forecast: Solar activity is expected to be very
low.
IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z:
The geomagnetic field was quiet. Solar wind speeds observed by the
ACE spacecraft have averaged around 380 km/s through the period with
occasional minor fluctuations in the IMF Bz between -4/+5 nT.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be mostly quiet on day one (26 May). Quiet to unsettled
conditions, with isolated active levels, are expected for days two
and three (27-28 May) as a recurrent coronal hole high speed stream
becomes geo-effective.
III. Event Probabilities 26 May-28 May
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 25 May 080
Predicted 26 May-28 May 080/080/080
90 Day Mean 25 May 108
V. Geomagnetic A Indices
Observed Afr/Ap 24 May 005/006
Estimated Afr/Ap 25 May 003/005
Predicted Afr/Ap 26 May-28 May 005/008-010/012-015/015
VI. Geomagnetic Activity Probabilities 26 May-28 May
A. Middle Latitudes
Active 05/20/25
Minor storm 01/05/10
Major-severe storm 01/01/05
B. High Latitudes
Active 15/30/35
Minor storm 05/10/15
Major-severe storm 01/05/05