Joint USAF/NOAA Report of Solar and Geophysical Activity 14 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 14 2200 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 105 Issued at 2200Z on 14 Apr 2012

IA. Analysis of Solar Active Regions and Activity from 13/2100Z
to 14/2100Z: Solar activity was very low. Region 1455 (N06W34)
produced occasional B-class x-ray flares during the first half of
the period. Region 1455 showed minor spot and penumbral decay during
the period and simplified from a beta-gamma to a beta magnetic
classification. New Regions 1458 (N07E70) and 1459 (S15E79) were
numbered. Neither were remarkable, but analysis was hampered due to
limb proximity. There were no Earth-directed CMEs observed during
the period.

IB. Solar Activity Forecast: Solar activity is expected to be very
low during days 1 – 3 (15 – 17 April) with a chance for isolated
C-class flares.

IIA. Geophysical Activity Summary 13/2100Z to 14/2100Z:
Geomagnetic field activity was at quiet to active levels. ACE solar
wind observations indicated the continued presence of a coronal hole
high-speed stream (CH HSS) with speeds in the 499 to 614 km/s range.
The greater than 2 MeV electron flux at geosynchronous orbit reached
high levels during the period.

IIB. Geophysical Activity Forecast: Geomagnetic field activity is
expected to be at quiet to unsettled levels on day 1 (15 April) with
a chance for active levels due to persistent CH HSS effects.
Activity is expected to decrease to mostly quiet levels during days
2 – 3 (16 – 17 April) as the CH HSS subsides.

III. Event Probabilities 15 Apr-17 Apr
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 14 Apr 098
Predicted 15 Apr-17 Apr 100/100/100
90 Day Mean 14 Apr 113

V. Geomagnetic A Indices
Observed Afr/Ap 13 Apr 013/022
Estimated Afr/Ap 14 Apr 008/012
Predicted Afr/Ap 15 Apr-17 Apr 010/010-004/005-004/005

VI. Geomagnetic Activity Probabilities 15 Apr-17 Apr
A. Middle Latitudes
Active 25/15/15
Minor storm 10/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 40/20/20
Minor storm 15/10/10
Major-severe storm 05/01/01