Joint USAF/NOAA Report of Solar and Geophysical Activity 13 Apr 2008

Product: Report of Solar-Geophysical Activity
Issued: 2008 Apr 13 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 104 Issued at 2200Z on 13 Apr 2008

IA. Analysis of Solar Active Regions and Activity from 12/2100Z to 13/2100Z: Solar activity was very low.

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

IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z: The geomagnetic field was quiet to unsettled. Solar wind velocity remains elevated in the 550 – 600 km/sec range. 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 at mid-latitudes for the forecast period, 14-16 April. Isolated active to minor storm conditions at high-latitudes remains a possibility due to the elevated solar wind velocity.

III. Event Probabilities 14 Apr-16 Apr

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

IV. Penticton 10.7 cm Flux

• Observed 13 Apr 069
• Predicted 14 Apr-16 Apr 070/070/070
• 90 Day Mean 13 Apr 072

V. Geomagnetic A Indices

• Observed Afr/Ap 12 Apr 008/011
• Estimated Afr/Ap 13 Apr 005/005
• Predicted Afr/Ap 14 Apr-16 Apr 005/005-005/005-005/005

VI. Geomagnetic Activity Probabilities 14 Apr-16 Apr

A. Middle Latitudes

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

B. High Latitudes

• Active 25/25/20
• Minor storm 15/15/10
• Major-severe storm 01/01/01