Report of Solar-Geophysical Activity

:Issued: 2005 Aug 01 2200 UTC
# Prepared jointly by the U.S. Dept. of Commerce, NOAA, # Space Environment Center and the U.S. Air Force.
#
Joint USAF/NOAA Report of Solar and Geophysical Activity SDF Number 213 Issued at 2200Z on 01 Aug 2005 IA. Analysis of Solar Active Regions and Activity from 31/2100Z to 01/2100Z: Solar activity was at moderate levels. Region 792

(N12E25) produced the largest flare during the period, a long duration M1/1f flare that occurred at 01/1351Z. This event generated an associated Tenflare (290 sfu), a Type IV radio sweep, and a CME that may have a weak geoeffective component. Region 792 underwent a decrease in sunspot number however, sunspot area has remained the same. This region continues to exhibit beta-gamma-delta magnetic features. Region 794 (S11E60) produced the second largest flare during the period, a C5 x-ray event that occurred at 01/1221Z. This region has shown growth in sunspot area over the interval. No new regions were numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be at moderate levels. Region 792 is capable of producing M-class flares.
IIA. Geophysical Activity Summary 31/2100Z to 01/2100Z:
The geomagnetic field was at quiet to active levels. The elevated activity may be attributed to a weak transient that was observed at the ACE spacecraft at approximately 01/0500Z. The greater than 10 MeV proton event that began at 27/2300Z ended at 01/1040Z, a maximum of 41 pfu occurred at 29/1715Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at predominantly quiet to unsettled levels. Isolated active conditions are possible on 04 August due to a glancing blow from the CME that was associated with the M1/1f flare that occurred today.
III. Event Probabilities 02 Aug-04 Aug
Class M 70/70/70
Class X 15/15/15
Proton 20/20/20
PCAF yellow
IV. Penticton 10.7 cm Flux
Observed 01 Aug 111
Predicted 02 Aug-04 Aug 110/105/105
90 Day Mean 01 Aug 096
V. Geomagnetic A Indices
Observed Afr/Ap 31 Jul 010/009
Estimated Afr/Ap 01 Aug 015/015
Predicted Afr/Ap 02 Aug-04 Aug 012/015-005/005-012/015 VI. Geomagnetic Activity Probabilities 02 Aug-04 Aug A. Middle Latitudes
Active 30/15/30
Minor storm 10/05/10
Major-severe storm 05/01/05
B. High Latitudes
Active 35/20/35
Minor storm 15/05/15
Major-severe storm 05/01/05

SUMMARY: Geomagnetic Sudden Impulse
Observed: 2005 Aug 01 0641 UTC
Deviation: 18 nT
Station: Boulder

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2005 Jul 30 0626 UTC
NOAA Scale: R2 - Moderate