Joint USAF/NOAA Report of Solar and Geophysical Activity 21 Jul 2008

Product: Report of Solar-Geophysical Activity
Issued: 2008 Jul 21 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 203 Issued at 2200Z on 21 Jul 2008

IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity was very low. No flares occurred during the past 24 hours. Region 1000 (S12W18) is spotless.

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

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field was quiet to unsettled, with an isolated active period from 0900-1200Z. The solar wind data at ACE indicated the passage of a solar sector boundary. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be mostly unsettled on day one (22 July), unsettled to active on day two (23 July), and mostly unsettled on day three (24 July). The increase in activity is forecast due to the expected effects of a recurrent coronal hole high speed stream.

III. Event Probabilities 22 Jul-24 Jul

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

IV. Penticton 10.7 cm Flux

• Observed 21 Jul 066
• Predicted 22 Jul-24 Jul 066/066/066
• 90 Day Mean 21 Jul 067

V. Geomagnetic A Indices

• Observed Afr/Ap 20 Jul 002/003
• Estimated Afr/Ap 21 Jul 008/010
• Predicted Afr/Ap 22 Jul-24 Jul 010/010-015/015-010/010

VI. Geomagnetic Activity Probabilities 22 Jul-24 Jul

A. Middle Latitudes

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

B. High Latitudes

• Active 25/50/25
• Minor storm 10/20/10
• Major-severe storm 01/05/01