Joint USAF/NOAA Report of Solar and Geophysical Activity 17 July 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Jul 17 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 198 Issued at 2200Z on 17 Jul 2011
IA. Analysis of Solar Active Regions and Activity from 16/2100Z
to 17/2100Z: Solar activity has been at very low levels for the past
24 hours. New Region 1257 (N19W56) emerged on the disk early in the
period and is already classified as Dai-beta group. Region 1257 also
produced the largest event of the period, a B7 flare at 17/1926Z.
IB. Solar Activity Forecast: Solar activity is expected to be at
very low to low levels with a slight chance for M-class events for
the next three days (18-19 July). The increase in forecasted
activity is due to the growth of new Region 1257 and the return of
old Region 1242 (N18, L=073).
IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z:
The geomagnetic field has been at quiet levels for 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 at quiet to unsettled levels for the next two days
(18-19 July) as a coronal hole high-speed stream (CH HSS) moves into
a geoeffective position. Quiet to active conditions are expected on
day three (20 July), as another CH HSS becomes geoeffective.
III. Event Probabilities 18 Jul-20 Jul
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 17 Jul 104
Predicted 18 Jul-20 Jul 104/104/102
90 Day Mean 17 Jul 097
V. Geomagnetic A Indices
Observed Afr/Ap 16 Jul 004/006
Estimated Afr/Ap 17 Jul 003/005
Predicted Afr/Ap 18 Jul-20 Jul 008/008-010/010-012/012
VI. Geomagnetic Activity Probabilities 18 Jul-20 Jul
A. Middle Latitudes
Active 10/20/25
Minor storm 01/01/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/25/35
Minor storm 01/01/10
Major-severe storm 01/01/01