Joint USAF/NOAA Report of Solar and Geophysical Activity 24 Apr 2007

Product: Report of Solar-Geophysical Activity
Issued: 2007 Apr 24 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 114 Issued at 2200Z on 24 Apr 2007

IA. Analysis of Solar Active Regions and Activity from 23/2100Z to 24/2100Z: Solar activity was very low. The background solar x-ray flux increased from below A-class to approximately A6 during the past 24 hours and a bright emerging flux region has rotated onto the east limb. However, no sunspots are visible in this region yet.

IB. Solar Activity Forecast: Solar activity is expected to be very low. There is a slight chance for a C-class flare from the east limb.

IIA. Geophysical Activity Summary 23/2100Z to 24/2100Z: The geomagnetic field was quiet. Solar wind speed remains slightly elevated at approximately 440 km/s.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet for the next three days (25 – 27 April).

III. Event Probabilities 25 Apr-27 Apr

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

IV. Penticton 10.7 cm Flux

• Observed 24 Apr 073
• Predicted 25 Apr-27 Apr 075/075/075
• 90 Day Mean 24 Apr 074

V. Geomagnetic A Indices

• Observed Afr/Ap 23 Apr 010/018
• Estimated Afr/Ap 24 Apr 003/005
• Predicted Afr/Ap 25 Apr-27 Apr 005/005-005/005-005/005

VI. Geomagnetic Activity Probabilities 25 Apr-27 Apr

A. Middle Latitudes

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

B. High Latitudes

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