Joint USAF/NOAA Report of Solar and Geophysical Activity 31 May 2007

Product: Report of Solar-Geophysical Activity
Issued: 2007 May 31 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 151 Issued at 2200Z on 31 May 2007

IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: Solar activity remained at low levels. Region 958 (S13E35) continues to decay. A C1 x-ray flare occurred at 31/1253Z, and appeared to have come from a source region just beyond the east limb. No new regions were numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be at very low to low levels.

IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field was at quiet levels. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels again today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at predominantly quiet levels on 01 and 02 June. A recurrent coronal hole high speed stream is expected to become geoeffective on 03 June. Active conditions are possible with the onset of the coronal hole.

III. Event Probabilities 01 Jun-03 Jun

• Class M 10/10/10
• Class X 01/01/01
• Proton 01/01/01
• PCAF Green

IV. Penticton 10.7 cm Flux

• Observed 31 May 075
• Predicted 01 Jun-03 Jun 075/075/075
• 90 Day Mean 31 May 073

V. Geomagnetic A Indices

• Observed Afr/Ap 30 May 003/004
• Estimated Afr/Ap 31 May 003/005
• Predicted Afr/Ap 01 Jun-03 Jun 003/005-003/005-010/015

VI. Geomagnetic Activity Probabilities 01 Jun-03 Jun

A. Middle Latitudes

• Active 15/15/25
• Minor storm 01/01/10
• Major-severe storm 01/01/05

B. High Latitudes

• Active 15/15/30
• Minor storm 05/05/15
• Major-severe storm 01/01/10