Joint USAF/NOAA Report of Solar and Geophysical Activity 11 July 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Jul 11 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 192 Issued at 2200Z on 11 Jul 2011
IA. Analysis of Solar Active Regions and Activity from 10/2100Z
to 11/2100Z: Solar activity was low. Region 1249 (S18W04) produced a
C2/1f at 11/1103Z with a Type II radio signature (est. shock
velocity 977 km/s). A CME associated with this event became visible
in STEREO COR-2 imagery at 11/1209Z and had an estimated speed of
750 km/s. Region 1251 (N15E68) was numbered overnight and is
currently an Hsx-alpha type region. All other regions on the disk
appear to be relatively stable.
IB. Solar Activity Forecast: Solar activity is expected to be low
with a slight chance for M-class activity for the next three days
(12-14 July).
IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z:
The geomagnetic field was quiet to active during the past 24 hours.
The increase in activity is due to a combination of the coronal hole
high speed stream (CH HSS) and the CME observed on 09 July. A Sudden
Impulse (SI) was observed at Earth at 11/0852Z with a 24 nT
deviation measured at the Boulder magnetometer indicating the
arrival of the CME. ACE spacecraft measurements indicated solar wind
velocities of 700 km/s towards the end of the period, most likely
due to the arrival of a second CH HSS.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be unsettled to active with isolated minor storm periods
for the next three days (12-14 July) due to the onset of a recurrent
CH HSS and the anticipated arrival (late on day two) of the CME
observed early this morning.
III. Event Probabilities 12 Jul-14 Jul
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 11 Jul 090
Predicted 12 Jul-14 Jul 092/094/094
90 Day Mean 11 Jul 099
V. Geomagnetic A Indices
Observed Afr/Ap 10 Jul 008/012
Estimated Afr/Ap 11 Jul 010/012
Predicted Afr/Ap 12 Jul-14 Jul 007/007-010/012-015/015
VI. Geomagnetic Activity Probabilities 12 Jul-14 Jul
A. Middle Latitudes
Active 20/30/15
Minor storm 10/15/05
Major-severe storm 01/01/01
B. High Latitudes
Active 25/30/15
Minor storm 15/15/05
Major-severe storm 01/01/01