Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 21 May 2012

By SpaceRef Editor
May 21, 2012
Filed under , , ,

:Product: Report of Solar-Geophysical Activity
:Issued: 2012 May 21 2200 UTC
# Prepared jointly by the U.S. Dept. of Commerce, NOAA,
# Space Weather Prediction Center and the U.S. Air Force.
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 142 Issued at 2200Z on 21 May 2012
IA. Analysis of Solar Active Regions and Activity from 20/2100Z
to 21/2100Z: Solar activity was very low. No Earth-directed CMEs
were observed during the period.
IB. Solar Activity Forecast: Solar activity is expected to be at
very low to low levels with a slight chance for an M-class flare for
the forecast period (22 – 24 May).
IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z:
The geomagnetic field was at quiet to active levels. A weak
interplanetary shock was observed at the ACE spacecraft at 21/1844Z.
An associated sudden impulse of 34 nT was observed at the Boulder
magnetometer at 21/1937Z. The geomagnetic field responded with an
active period between 21/1800 – 2100Z. This activity was likely
attributable to the arrival of the 18 May CME.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels with a chance for active
periods on days 1-2 (22 – 23 May) as recurrent coronal hole high
speed streams (CH HSS) move into a geoeffective position. Quiet to
unsettled conditions are expected on day 3 (24 May) as effects of
the CH HSS wane.
III. Event Probabilities 22 May-24 May
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 21 May 125
Predicted 22 May-24 May 125/125/120
90 Day Mean 21 May 116
V. Geomagnetic A Indices
Observed Afr/Ap 20 May 012/011
Estimated Afr/Ap 21 May 005/007
Predicted Afr/Ap 22 May-24 May 010/010-007/010-007/008
VI. Geomagnetic Activity Probabilities 22 May-24 May
A. Middle Latitudes
Active 20/20/10
Minor storm 10/10/01
Major-severe storm 01/01/01
B. High Latitudes
Active 25/25/15
Minor storm 15/15/05
Major-severe storm 01/01/01

SpaceRef staff editor.