Joint USAF/NOAA Report of Solar and Geophysical Activity 26 Apr 2007

Product: Report of Solar-Geophysical Activity
Issued: 2007 Apr 26 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 116 Issued at 2200Z on 26 Apr 2007

IA. Analysis of Solar Active Regions and Activity from 25/2100Z to 26/2100Z: Solar activity was very low. Region 953 (S10E61) produced only B-class activity during the past 24 hours.

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

IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z: The geomagnetic field has been quiet to unsettled.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled on 27 April. A recurrent coronal hole high speed stream is expected to become geoeffective on 28 April. Expect unsettled to minor storm conditions on 28 – 29 April.

III. Event Probabilities 27 Apr-29 Apr

• Class M 05/05/05
• Class X 01/01/01
• Proton 01/01/01
• PCAF Green

IV. Penticton 10.7 cm Flux

• Observed 26 Apr 081
• Predicted 27 Apr-29 Apr 080/080/080
• 90 Day Mean 26 Apr 074

V. Geomagnetic A Indices

• Observed Afr/Ap 25 Apr 004/005
• Estimated Afr/Ap 26 Apr 005/005
• Predicted Afr/Ap 27 Apr-29 Apr 005/005-015/025-015/015

VI. Geomagnetic Activity Probabilities 27 Apr-29 Apr

A. Middle Latitudes

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

B. High Latitudes

• Active 10/40/35
• Minor storm 05/25/20
• Major-severe storm 01/10/05