Joint USAF/NOAA Report of Solar and Geophysical Activity 22 May 2008

Product: Report of Solar-Geophysical Activity
Issued: 2008 May 22 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 143 Issued at 2200Z on 22 May 2008

IA. Analysis of Solar Active Regions and Activity from 21/2100Z to 22/2100Z: Solar activity was very low. The visible disk is spotless. A 10 degree filament near S25E08 disappeared between 0734-1338Z.

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

IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z: The geomagnetic field was quiet to unsettled. Solar wind speed decreased gradually from approximately 620 km/s to values ranging between 580 – 520 km/s. The solar wind signatures were consistent with a high speed stream from a coronal hole.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled with a chance for isolated active periods for the next three days (23 – 25 May) due to persistent effects from the high speed stream.

III. Event Probabilities 23 May-25 May

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

IV. Penticton 10.7 cm Flux

• Observed 22 May 069
• Predicted 23 May-25 May 068/068/068
• 90 Day Mean 22 May 071

V. Geomagnetic A Indices

• Observed Afr/Ap 21 May 009/013
• Estimated Afr/Ap 22 May 010/010
• Predicted Afr/Ap 23 May-25 May 008/010-008/010-008/010

VI. Geomagnetic Activity Probabilities 23 May-25 May

A. Middle Latitudes

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

B. High Latitudes

• Active 40/40/25
• Minor storm 20/20/15
• Major-severe storm 10/10/05