Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 17 April 2012

By SpaceRef Editor
April 17, 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 17 2200 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 108 Issued at 2200Z on 17 Apr 2012

IA. Analysis of Solar Active Regions and Activity from 16/2100Z
to 17/2100Z: Solar activity has been low for the past 24 hours. A
long duration C1 flare was observed from new Region 1461 (N13E66) at
17/0809Z. An associated CME became visible in LASCO C2 imagery at
17/0800Z but does not appear to be Earth-directed. A filament
eruption occurred at approximately 17/1330Z near N24W40. The
associated CME was first visible in LASCO C2 imagery at 17/1424Z but
is not expected to be geoeffective. New Region 1460 (N16E26) was
also numbered overnight and is considered a Dso-beta type spot
group. Region 1459 (S15E40) has shown a significant decrease in
areal coverage and is now a Dao-beta type spot group.

IB. Solar Activity Forecast: Solar activity is expected to be low
with a slight chance for an M-class flare for the next three days
(18-20 April).

IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z:
The geomagnetic field was mostly quiet during the past 24 hours. The
greater than 2 MeV electron flux at geosynchronous orbit reached
high levels during the period.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be mostly quiet on days one and two (18-19 April). Quiet
to unsettled conditions are expected with a chance for isolated
active periods on day three (20 April) due to a recurrent Solar
Sector Boundary Crossing (SSBC).

III. Event Probabilities 18 Apr-20 Apr
Class M 20/15/10
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 17 Apr 114
Predicted 18 Apr-20 Apr 115/115/110
90 Day Mean 17 Apr 112

V. Geomagnetic A Indices
Observed Afr/Ap 16 Apr 005/005
Estimated Afr/Ap 17 Apr 006/008
Predicted Afr/Ap 18 Apr-20 Apr 004/005-004/005-007/008

VI. Geomagnetic Activity Probabilities 18 Apr-20 Apr
A. Middle Latitudes
Active 10/10/25
Minor storm 01/01/10
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor storm 15/15/30
Major-severe storm 10/10/30

SpaceRef staff editor.