Joint USAF/NOAA Report of Solar and Geophysical Activity 15 July 2012

:Product: Report of Solar-Geophysical Activity
:Issued: 2012 Jul 15 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 197 Issued at 2200Z on 15 Jul 2012
IA. Analysis of Solar Active Regions and Activity from 14/2100Z
to 15/2100Z: Solar activity has been at low levels for the past 24
hours. Region 1520 (S17W48) remains the largest and most
magnetically complex region on the disk, however it has remained
rather stable and quiet. Regions 1521 (S21W60) and 1519 (S17W68)
have been the most active regions producing low level C-class
events. Both regions have shown moderate growth in sunspot area and
magnetic complexity. No Earth directed CME’s were observed during
the period.
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
(16-18 July).
IIA. Geophysical Activity Summary 14/2100Z to 15/2100Z:
The geomagnetic field has been at active to major storm levels for
the past 24 hours. These elevated levels can be attributed to
continuing CME effects. Measurements from the ACE spacecraft showed
variable IMF total field strength and occasional negative Bz early
in the period. Around 0600Z, total IMF peaked around 28 nT, with the
Bz component reaching a maximum deflection of -18 nT. These levels
remained almost constant and elevated throughout the remainder of
the summary period. Multiple major to severe storm periods at high
latitudes with minor to major storm periods at mid latitudes were
observed during the period, due to the 16 hours of sustained
negative Bz coupled with elevated (500-600 km/s) solar wind speeds.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to active levels on day one (16 July) as CME
effects wane. A return to predominantly quiet levels is expected on
days two and three (17-18 July).
III. Event Probabilities 16 Jul-18 Jul
Class M 40/40/40
Class X 15/15/15
Proton 15/15/15
PCAF green
IV. Penticton 10.7 cm Flux
Observed 15 Jul 141
Predicted 16 Jul-18 Jul 135/130/120
90 Day Mean 15 Jul 128
V. Geomagnetic A Indices
Observed Afr/Ap 14 Jul 011/018
Estimated Afr/Ap 15 Jul 032/049
Predicted Afr/Ap 16 Jul-18 Jul 013/018-006/005-005/005
VI. Geomagnetic Activity Probabilities 16 Jul-18 Jul
A. Middle Latitudes
Active 30/05/05
Minor storm 10/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor storm 30/10/10
Major-severe storm 40/05/05