Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 10 July 2011

By SpaceRef Editor
July 11, 2011
Filed under , , ,

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Jul 10 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 191 Issued at 2200Z on 10 Jul 2011
IA. Analysis of Solar Active Regions and Activity from 09/2100Z
to 10/2100Z: Solar activity has been at very low levels for the past
24 hours. Region 1247 (S18W15) grew in sunspot count and magnetic
complexity but has remained stable and quiet. Region 1250 (S25E48)
emerged on the disk early in the period and has grown rapidly to the
second largest group on the visible disk. Two CME’s were observed
during the period but after careful analysis, both CME’s were
determined to be backsided and non-geoeffective.
IB. Solar Activity Forecast: Solar activity is expected to be at
low levels with a slight chance for M-class events for the next
three days (11-13 July) as both Region 1247 and 1250 continue to
grow and evolve.
IIA. Geophysical Activity Summary 09/2100Z to 10/2100Z:
The geomagnetic field has been at quiet to active levels for the past
24 hours. The elevated levels are due to the continued effects of a
coronal hole high speed stream (CH HSS). Solar wind speeds, as
measured by the ACE spacecraft, peaked at around 540 km/s but has
since started to decay to around 450 km/s.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to remain quiet to unsettled for day one (11 July) as the
effects of the CH HSS wane. On day two (12 July), levels ranging
from quiet to active are expected due to the combined effects from
another CH HSS and the CME observed on 09 July. A return to quiet to
unsettled levels is expected on day three (13 July) as effects from
both events wane.
III. Event Probabilities 11 Jul-13 Jul
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 10 Jul 091
Predicted 11 Jul-13 Jul 092/094/094
90 Day Mean 10 Jul 099
V. Geomagnetic A Indices
Observed Afr/Ap 09 Jul 010/012
Estimated Afr/Ap 10 Jul 010/010
Predicted Afr/Ap 11 Jul-13 Jul 007/007-012/012-007/007
VI. Geomagnetic Activity Probabilities 11 Jul-13 Jul
A. Middle Latitudes
Active 20/30/20
Minor storm 05/10/05
Major-severe storm 01/01/01
B. High Latitudes
Active 25/40/25
Minor storm 05/10/05
Major-severe storm 01/01/01

SpaceRef staff editor.