Joint USAF/NOAA Report of Solar and Geophysical Activity 5 February 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Feb 05 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 036 Issued at 2200Z on 05 Feb 2011
IA. Analysis of Solar Active Regions and Activity from 04/2100Z
to 05/2100Z: Solar activity has been very low for the past 24 hours.
Region 1152 (S18W14) and Region 1153 (N15W31) have begun to decay
with a loss in areal coverage, magnetic complexity, and a reduced
sunspot number. Region 1150 (S20, L=187) decayed to spotless plage
early in the period.
IB. Solar Activity Forecast: Solar activity is expected to be very
low with a slight chance for C-class activity for the next three
days (06-08 February).
IIA. Geophysical Activity Summary 04/2100Z to 05/2100Z:
The geomagnetic field has been at quiet to active levels with an
isolated period at G1 ,minor storm levels, from 4/2100Z-4/2400Z.
This increase in activity was associated with a reverse shock behind
a slow moving CME observed on 30 January. Observations from the ACE
spacecraft indicated the effects of the shock subsided around
4/0421Z, as a recurrent coronal hole high speed stream, in which the
CME was embedded, regained dominance. Throughout the period, the
total Interplanetary Magnetic Field (IMF) decayed from 17 nT at
04/2106Z to 3nT at 05/2008Z. Solar wind speeds peaked at around 675
km/s at 05/0536Z, but speeds began to decrease as the day
progressed.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled for the next two days (06-07
February) as the effects of the latest recurrent coronal hole high
speed stream wane. A return to quiet levels is expected on day three
(08 February).
III. Event Probabilities 06 Feb-08 Feb
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 05 Feb 081
Predicted 06 Feb-08 Feb 080/080/080
90 Day Mean 05 Feb 084
V. Geomagnetic A Indices
Observed Afr/Ap 04 Feb 012/021
Estimated Afr/Ap 05 Feb 015/018
Predicted Afr/Ap 06 Feb-08 Feb 008/010-008/008-005/005
VI. Geomagnetic Activity Probabilities 06 Feb-08 Feb
A. Middle Latitudes
Active 20/20/05
Minor storm 05/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 25/25/10
Minor storm 10/10/01
Major-severe storm 01/01/01