Joint USAF/NOAA Report of Solar and Geophysical Activity 27 July 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Jul 27 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 208 Issued at 2200Z on 27 Jul 2011
IA. Analysis of Solar Active Regions and Activity from 26/2100Z
to 27/2100Z: Solar activity was moderate. Region 1260 (N18E30)
produced a M1/1n flare at 1607Z as well as numerous C-class flares
during the past 24 hours. This region showed some magnetic
complexity (magnetic class beta-gamma) and changed steadily
throughout the day. Region 1261 (N15E60) is the largest group on the
disk (250 millionths) but is a simple magnetic beta group and only
produced one subflare during the day. New Region 1262 (N16W38) was
assigned and is a small D-type group with a weak delta configuration
in the trailing portion of the group. Despite its magnetic
complexity 1262 did not produce any flares. The eruption of a
filament from the northeast quadrant was observed at about 0620Z and
was associated with a faint, slow coronal mass ejection off the
northeast limb as observed by the LASCO C2 coronagraph beginning at
0642Z.
IB. Solar Activity Forecast: Solar activity is expected to be
predominantly low but there is a chance for additional isolated
M-class flares from Region 1260.
IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z:
The geomagnetic field was quiet. The greater than 2 MeV electron flux
at geosynchronous orbit reached high levels during the period.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet for the next three days (28-30 July). Recent
analysis from Stereo-B and solar imagery suggest that the previously
anticipated high speed stream from a coronal hole is most likely to
start affecting Earth on 31 July.
III. Event Probabilities 28 Jul-30 Jul
Class M 40/40/40
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 27 Jul 099
Predicted 28 Jul-30 Jul 100/100/105
90 Day Mean 27 Jul 095
V. Geomagnetic A Indices
Observed Afr/Ap 26 Jul 005/005
Estimated Afr/Ap 27 Jul 005/005
Predicted Afr/Ap 28 Jul-30 Jul 005/005-005/005-005/005
VI. Geomagnetic Activity Probabilities 28 Jul-30 Jul
A. Middle Latitudes
Active 05/05/05
Minor storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 05/05/05
Minor storm 01/01/01
Major-severe storm 01/01/01