Joint USAF/NOAA Report of Solar and Geophysical Activity 26 July 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Jul 26 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 207 Issued at 2200Z on 26 Jul 2011
IA. Analysis of Solar Active Regions and Activity from 25/2100Z
to 26/2100Z: Solar activity was low during the past 24 hours.
Region 1260 (N20E45) produced the only C-class event of the period,
a C1 flare at 26/0339Z. Region 1260 has grown significantly and is
classified as a Dao type spot group. New Region 1261 (N16E74) was
numbered today. This region is still rotating onto the visible disk
and initial observations indicated a Dho type spot group. Both
regions were magnetically simple.
IB. Solar Activity Forecast: Solar activity is expected to be very
low to low for the next three days (27-29 July). Both Regions 1260
and 1261 are likely to produce C-class activity, with the remote
possibility of an isolated M-class event.
IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z:
The geomagnetic field has been 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 quiet on day one (27 July). Days two and three (28-29
July) are expected to be quiet to unsettled with isolated active
periods. The increase in activity is forecast due to the expected
arrival of a recurrent coronal hole high speed stream.
III. Event Probabilities 27 Jul-29 Jul
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 26 Jul 094
Predicted 27 Jul-29 Jul 095/097/099
90 Day Mean 26 Jul 095
V. Geomagnetic A Indices
Observed Afr/Ap 25 Jul 010/012
Estimated Afr/Ap 26 Jul 004/005
Predicted Afr/Ap 27 Jul-29 Jul 005/005-010/012-012/012
VI. Geomagnetic Activity Probabilities 27 Jul-29 Jul
A. Middle Latitudes
Active 05/15/15
Minor storm 01/05/10
Major-severe storm 01/01/01
B. High Latitudes
Active 05/15/25
Minor storm 01/10/10
Major-severe storm 01/01/01