Joint USAF/NOAA Report of Solar and Geophysical Activity 10 Apr 2008

Product: Report of Solar-Geophysical Activity
Issued: 2008 Apr 10 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 101 Issued at 2200Z on 10 Apr 2008

IA. Analysis of Solar Active Regions and Activity from 09/2100Z to 10/2100Z: Solar activity was very low.

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

IIA. Geophysical Activity Summary 09/2100Z to 10/2100Z: The geomagnetic field ranged from quiet to unsettled. Solar wind speed remains elevated to greater than 600 km/sec due to the continued influence of a coronal hole high speed stream. 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 11 April and abate to predominately quiet for 12 – 13 April as the coronal hole high speed stream rotates out of its geoeffective position.

III. Event Probabilities 11 Apr-13 Apr

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

IV. Penticton 10.7 cm Flux

• Observed 10 Apr 068
• Predicted 11 Apr-13 Apr 070/070/070
• 90 Day Mean 10 Apr 072

V. Geomagnetic A Indices

• Observed Afr/Ap 09 Apr 009/012
• Estimated Afr/Ap 10 Apr 007/010
• Predicted Afr/Ap 11 Apr-13 Apr 007/008-005/005-005/005

VI. Geomagnetic Activity Probabilities 11 Apr-13 Apr

A. Middle Latitudes

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

B. High Latitudes

• Active 25/20/15
• Minor storm 15/10/05
• Major-severe storm 05/05/01