Joint USAF/NOAA Report of Solar and Geophysical Activity 08 April 2012

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Weather Prediction Center and the U.S. Air Force.
Updated 2012 Apr 08 2200 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 099 Issued at 2200Z on 08 Apr 2012

IA. Analysis of Solar Active Regions and Activity from 07/2100Z
to 08/2100Z: Solar activity was very low. Occasional B-class flares
occurred. A filament erupted from the northwest quadrant during
approximately 07/1825 – 1900Z. The eruption was associated with a
partial-halo CME with an estimated plane of sky speed of 690 km/s.
Most of the CME mass appeared to be directed southwestward of Earth
and is not expected to be significantly geoeffective. No new regions
were numbered.

IB. Solar Activity Forecast: Solar activity is expected to be very
low during days 1 – 3 (09 – 11 April) with a chance for an isolated
C-class flare.

IIA. Geophysical Activity Summary 07/2100Z to 08/2100Z:
The geomagnetic field was quiet.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at unsettled levels on day 1 (09 April) with a chance
for active levels due to a CME passage that is expected to begin
early in the day. There will also be a chance for minor storm levels
at high latitudes on day 1. Field activity is expected to decrease
to quiet to unsettled levels during days 2 – 3 (10 – 11 April).

III. Event Probabilities 09 Apr-11 Apr
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF Green

IV. Penticton 10.7 cm Flux
Observed 08 Apr 093
Predicted 09 Apr-11 Apr 095/095/095
90 Day Mean 08 Apr 115

V. Geomagnetic A Indices
Observed Afr/Ap 07 Apr 003/014
Estimated Afr/Ap 08 Apr 006/006
Predicted Afr/Ap 09 Apr-11 Apr 013/015-006/008-007/008

VI. Geomagnetic Activity Probabilities 09 Apr-11 Apr
A. Middle Latitudes
Active 25/15/15
Minor storm 05/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 20/15/20
Minor storm 35/10/25
Major-severe storm 30/05/15