Joint USAF/NOAA Report of Solar and Geophysical Activity 17 Apr 2007

Product: Report of Solar-Geophysical Activity
Issued: 2007 Apr 17 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 107 Issued at 2200Z on 17 Apr 2007

IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity was very low. Region 952 (S08W73) was numbered today.

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

IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field was quiet to unsettled.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be predominantly quiet to unsettled for the next three days (18-20 April). Isolated active periods are expected on 19-20 April, with a chance for isolated minor storm conditions at high latitudes on 20 April, due to a favorably positioned coronal hole.

III. Event Probabilities 18 Apr-20 Apr

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

IV. Penticton 10.7 cm Flux

• Observed 17 Apr 069
• Predicted 18 Apr-20 Apr 070/070/070
• 90 Day Mean 17 Apr 075

V. Geomagnetic A Indices

• Observed Afr/Ap 16 Apr 000/001
• Estimated Afr/Ap 17 Apr 005/007
• Predicted Afr/Ap 18 Apr-20 Apr 005/005-008/010-015/015

VI. Geomagnetic Activity Probabilities 18 Apr-20 Apr

A. Middle Latitudes

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

B. High Latitudes

• Active 15/20/30
• Minor storm 05/15/20
• Major-severe storm 01/05/10