Joint USAF/NOAA Report of Solar and Geophysical Activity 11 April 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Apr 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 Report of Solar and Geophysical Activity
SDF Number 101 Issued at 2200Z on 11 Apr 2011
IA. Analysis of Solar Active Regions and Activity from 10/2100Z
to 11/2100Z: Solar activity was low. At 11/0912Z GOES 15 XRS
detected a B9.2 flare. The flare was off the east limb from
returning old Region 1176 (L= 278). A CME was observed on Stereo B
EUV imagery at approximately the same time. This region also
produced a C-class flare at 11/1602Z. The other regions on the
visible disk were quiet and stable. New Region 1190 (N12E35) was
numbered today.
IB. Solar Activity Forecast: Solar activity is expected to be very
low to low with a chance for C-class flares for the next three days
(12 – 14 April).
IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z:
The geomagnetic field was at quiet to unsettled levels. Solar wind
speeds measured at the ACE Spacecraft increased from approximately
360 km/s to approximately 420 km/s in response to a coronal hole
high-speed stream.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at mostly quiet levels for the next three days (12 –
14 April) as the coronal hole high-speed stream effects decrease.
III. Event Probabilities 12 Apr-14 Apr
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 11 Apr 106
Predicted 12 Apr-14 Apr 100/100/105
90 Day Mean 11 Apr 101
V. Geomagnetic A Indices
Observed Afr/Ap 10 Apr 003/005
Estimated Afr/Ap 11 Apr 010/010
Predicted Afr/Ap 12 Apr-14 Apr 005/005-005/005-005/005
VI. Geomagnetic Activity Probabilities 12 Apr-14 Apr
A. Middle Latitudes
Active 20/10/10
Minor storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 25/15/15
Minor storm 01/01/01
Major-severe storm 01/01/01