Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 22 April 2012

By SpaceRef Editor
April 22, 2012
Filed under , ,

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Weather Prediction Center and the U.S. Air Force.
Updated 2012 Apr 22 2200 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 113 Issued at 2200Z on 22 Apr 2012

IA. Analysis of Solar Active Regions and Activity from 21/2100Z
to 22/2100Z: Solar activity was low. Occasional low-level C-class
flares occurred. Region 1459 (S15W25 – Dki/beta) produced a single
C-class flare and showed signs of gradual decay in its intermediate
portion. Region 1465 (S18E14 – Dai/beta) produced two C-class flares
and showed spot and penumbral development as well as some polarity
mixing in its intermediate portion. New Region 1466 (N12E29 –
Cso/beta) emerged early in the period and gradually grew. No
Earth-directed CMEs were observed during the period.

IB. Solar Activity Forecast: Solar activity is expected to be low
through the period (23 – 25 April) with a chance for an isolated
M-class flare.

IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z:
Geomagnetic field activity was at quiet to unsettled levels with a
brief interval of active levels at high latitudes.

IIB. Geophysical Activity Forecast: Geomagnetic field activity is
expected to be at quiet to unsettled levels during days 1 – 2 (23 –
24 April) with a chance for active levels due mainly to a recurrent
coronal hole high-speed stream. Weak CME-passage effects are also
possible on day 1 from the partial-halo CME observed on 19 April.
Field activity is expected to decrease to mostly quiet levels on day
3 (25 April).

III. Event Probabilities 23 Apr-25 Apr
Class M 30/30/30
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 22 Apr 148
Predicted 23 Apr-25 Apr 145/145/140
90 Day Mean 22 Apr 112

V. Geomagnetic A Indices
Observed Afr/Ap 21 Apr 006/008
Estimated Afr/Ap 22 Apr 008/012
Predicted Afr/Ap 23 Apr-25 Apr 010/010-008/010-007/008

VI. Geomagnetic Activity Probabilities 23 Apr-25 Apr
A. Middle Latitudes
Active 25/25/15
Minor storm 05/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 30/30/20
Minor storm 10/10/01
Major-severe storm 01/01/01

SpaceRef staff editor.