Joint USAF/NOAA Report of Solar and Geophysical Activity 28 Apr 2006

Product: Report of Solar-Geophysical Activity
Issued: 2006 Apr 28 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 118 Issued at 2200Z on 28 Apr 2006

IA. Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: Solar activity was low. Region 875 (S11E06) produced a C1 flare at 28/0826Z.

IB. Solar Activity Forecast: Solar activity is expected to be low with a slight chance of M-class activity from Region 875.

IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field was quiet to unsettled with one major storm period from 0600 – 0900 UTC following a discontinuity in the solar wind.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled for the next three days (29 April – 01 May). III. Event Probabilities 29 Apr-01 May

• Class M 20/20/20
• Class X 01/01/01
• Proton 01/01/01
• PCAF green

IV. Penticton 10.7 cm Flux

• Observed 28 Apr 100
• Predicted 29 Apr-01 May 100/100/100
• 90 Day Mean 28 Apr 080

V. Geomagnetic A Indices

• Observed Afr/Ap 27 Apr 003/005
• Estimated Afr/Ap 28 Apr 014/015
• Predicted Afr/Ap 29 Apr-01 May 005/007-005/007-005/007

VI. Geomagnetic Activity Probabilities 29 Apr-01 May A. Middle Latitudes

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

B. High Latitudes

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