Joint USAF/NOAA Report of Solar and Geophysical Activity 09 Apr 2007

Product: Report of Solar-Geophysical Activity
Issued: 2007 Apr 09 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 099 Issued at 2200Z on 09 Apr 2007

IA. Analysis of Solar Active Regions and Activity from 08/2100Z to 09/2100Z: Solar activity was very low. No new regions were numbered today.

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

IIA. Geophysical Activity Summary 08/2100Z to 09/2100Z: The geomagnetic field was quiet to active. The magnetic structure of the solar wind appears to be consistent with a co-rotating interaction region coupled with a solar sector boundary crossing. Solar wind increased from around 350 km/s to 480 km/s by approximately 09/1700 UTC. 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 quiet to unsettled with isolated active periods possible on 10 April due to coronal hole activity. On 11 and 12 April, conditions are expected to be quiet to unsettled.

III. Event Probabilities 10 Apr-12 Apr

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

IV. Penticton 10.7 cm Flux

• Observed 09 Apr 070
• Predicted 10 Apr-12 Apr 070/070/070
• 90 Day Mean 09 Apr 075

V. Geomagnetic A Indices

• Observed Afr/Ap 08 Apr 002/003
• Estimated Afr/Ap 09 Apr 008/015
• Predicted Afr/Ap 10 Apr-12 Apr 010/015-008/010-008/010

VI. Geomagnetic Activity Probabilities 10 Apr-12 Apr

A. Middle Latitudes

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

B. High Latitudes

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