Joint USAF/NOAA Report of Solar and Geophysical Activity 13 May 2012

:Product: Report of Solar-Geophysical Activity
:Issued: 2012 May 13 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 134 Issued at 2200Z on 13 May 2012
IA. Analysis of Solar Active Regions and Activity from 12/2100Z
to 13/2100Z: Solar activity has been at low levels for the past 24
hours. Region 1476 (N09W33) continues to be the most dominant region
on the disk with an area of 840 millionths and is magnetically
classified as beta-gamma-delta. However, Region 1476 is currently in
a decay phase and only producing C-class x-ray events. Region 1479
(N15E40) was split into two sunspot groups after magnetogram
analysis, with the leader group retaining the Region 1479 number,
and the trailer group being numbered Region 1482 (N14E51). Three new
regions were also numbered today, Region 1481 (S10E61), Region 1483
(S27E51) and Region 1484 (N10E75).
IB. Solar Activity Forecast: Solar activity is expected to be at
low levels with a chance for M-class events for the next three days
(14 – 16 May) as Region 1476 continues to rotate towards the west
limb of the solar disk.
IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z:
The geomagnetic field has been at quiet to unsettled levels with
isolated periods at minor storm levels observed at high latitudes.
Measurements, by the ACE spacecraft, indicate the waning effects of
the latest coronal hole high speed stream, as solar wind speeds
decreased from 600 km/s to around 500 km/s. 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 at quiet to unsettled levels with a chance for active
periods on day one (14 May), as a CME, observed leaving the solar
disk on 12 May, is forecasted to become geoeffective. Most of the
mass of this CME event is expected to miss Earth, thus quiet to
unsettled levels with a chance of active levels, are also expected
on day two (15 May). As effects of the CME wane, a return to quiet
to unsettled levels is expected on day three (16 May).
III. Event Probabilities 14 May-16 May
Class M 35/35/35
Class X 05/05/05
Proton 05/05/05
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 13 May 131
Predicted 14 May-16 May 130/130/130
90 Day Mean 13 May 114
V. Geomagnetic A Indices
Observed Afr/Ap 12 May 008/010
Estimated Afr/Ap 13 May 010/010
Predicted Afr/Ap 14 May-16 May 007/010-014/012-006/008
VI. Geomagnetic Activity Probabilities 14 May-16 May
A. Middle Latitudes
Active 20/30/10
Minor storm 05/10/01
Major-severe storm 01/01/01
B. High Latitudes
Active 30/35/20
Minor storm 15/25/10
Major-severe storm 01/10/01