Joint USAF/NOAA Report of Solar and Geophysical Activity 15 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 15 2200 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 106 Issued at 2200Z on 15 Apr 2012

IA. Analysis of Solar Active Regions and Activity from 14/2100Z
to 15/2100Z: Solar activity increased to low levels. Two low-level
C-class flares occurred from a source beyond the northeast limb.
Region 1459 (S16E64) produced occasional B-class flares while it
rotated more fully into view as a Dai-type group with a beta
magnetic classification. Region 1455 (N05W46) showed intermediate
spot development during the period and was classified as a Dsi-type
with a beta magnetic classification. Small Axx-type Region 1454
(S12W00) produced a B9 x-ray flare at 15/0908Z associated with a
slow partial-halo CME, which is not expected to be geoeffective. No
new regions were numbered.

IB. Solar Activity Forecast: Solar activity is expected to be low
through the period (16 – 18 April).

IIA. Geophysical Activity Summary 14/2100Z to 15/2100Z:
Geomagnetic field activity decreased to mostly quiet levels. The
greater than 2 MeV electron flux at geosynchronous orbit was at high
levels throughout the period.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet levels during the period (16 – 18 April).

III. Event Probabilities 16 Apr-18 Apr
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 15 Apr 102
Predicted 16 Apr-18 Apr 100/100/100
90 Day Mean 15 Apr 113

V. Geomagnetic A Indices
Observed Afr/Ap 14 Apr 007/011
Estimated Afr/Ap 15 Apr 006/005
Predicted Afr/Ap 16 Apr-18 Apr 004/005-004/005-004/005

VI. Geomagnetic Activity Probabilities 16 Apr-18 Apr
A. Middle Latitudes
Active 10/10/10
Minor storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor storm 01/01/01
Major-severe storm 01/01/01