Joint USAF/NOAA Report of Solar and Geophysical Activity 31 March 2012

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Weather Prediction Center and the U.S. Air Force.
Updated 2012 Mar 31 2200 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 091 Issued at 2200Z on 31 Mar 2012

IA. Analysis of Solar Active Regions and Activity from 30/2100Z
to 31/2100Z: Solar activity was low. A single C1/Sf flare was
observed from Region 1451 (N17E53) at 30/2112Z. New Region 1451 was
a simple Cro type group with a beta magnetic configuration. New
Region 1450 (N15E38) was also numbered and also a Cro type group
with beta magnetic characteristics. The remaining regions were
quiet and magnetically simple.

IB. Solar Activity Forecast: Solar activity is expected to be at
very low to low levels. An isolated C-class flare is likely with a
slight chance for an M-class event.

IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z:
The geomagnetic field was at quiet levels. Solar wind speed measured at the ACE spacecraft ranged from around 450 km/s at the beginning of the period to 350 km/s at the end of the period. Bz was generally neutral. ACE data suggested a solar sector boundary crossing from negative to positive sector around 31/14Z.

IIB. Geophysical Activity Forecast: The geomagentic field is
expected to be predominantly quiet for the next three days (01-03
April).

III. Event Probabilities 01 Apr-03 Apr
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF Green

IV. Penticton 10.7 cm Flux
Observed 31 Mar 110
Predicted 01 Apr-03 Apr 115/115/120
90 Day Mean 31 Mar 118

V. Geomagnetic A Indices
Observed Afr/Ap 30 Mar 006/004
Estimated Afr/Ap 31 Mar 005/005
Predicted Afr/Ap 01 Apr-03 Apr 006/005-006/005-006/005

VI. Geomagnetic Activity Probabilities 01 Apr-03 Apr
A. Middle Latitudes
Active 05/05/05
Minor storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor storm 15/15/15
Major-severe storm 05/05/05