Joint USAF/NOAA Report of Solar and Geophysical Activity 22 May 2007

Product: Report of Solar-Geophysical Activity
Issued: 2007 May 22 2200 UTC
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.

IA. Analysis of Solar Active Regions and Activity from 21/2100Z to 22/2100Z: Solar activity continues at very low levels. Region 956 (N03W46) produced a long duration B3 flare at 22/1447Z. This event had an associated Type II radio sweep (585km/s), and a coronal mass ejection was observed on LASCO imagery. Region 956 is in decay and has decreased considerably in size over the last 48 hours, however, the region still exhibits minor magnetic complexity.

IB. Solar Activity Forecast: Solar activity is expected to continue at very low levels. There is a slight chance of a C-class flare from Region 956.

IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z: The geomagnetic field was quiet to unsettled.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to range from quiet to minor storm levels. Quiet to unsettled conditions are expected on 23 May. A recurrent coronal hole high speed stream will rotate into a geoeffective position on 24 May and produce active to minor storm periods on 24 and 25 May.

III. Event Probabilities 23 May-25 May

• Class M 05/05/05
• Class X 01/01/01
• Proton 01/01/01
• PCAF green

IV. Penticton 10.7 cm Flux

• Observed 22 May 072
• Predicted 23 May-25 May 075/075/075
• 90 Day Mean 22 May 074

V. Geomagnetic A Indices

• Observed Afr/Ap 21 May 006/006
• Estimated Afr/Ap 22 May 005/008
• Predicted Afr/Ap 23 May-25 May 008/010-010/015-020/025

VI. Geomagnetic Activity Probabilities 23 May-25 May

A. Middle Latitudes

• Active 20/30/40
• Minor storm 05/10/20
• Major-severe storm 01/01/05

B. High Latitudes

• Active 20/40/50
• Minor storm 05/20/30
• Major-severe storm 01/10/15