Joint USAF/NOAA Report of Solar and Geophysical Activity 21 Feb 2004

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.

Updated 2004 Feb 21 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 052 Issued at 2200Z on 21 Feb 2004

IA. Analysis of Solar Active Regions and Activity from 20/2100Z
to 21/2100Z: Solar activity was at very low levels. New Region 564
(N14E42) produced a B6 flare at 1444Z. Other spot groups on the
disk produced little activity and are magnetically simple.

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

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z:
The geomagnetic field was at mostly quiet levels with one period of
unsettled conditions observed at 1500Z. Greater than 2 MeV electron
flux at geosynchronous orbit reached high levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels. Isolated active
conditions are possible, due to a small and variable high speed
stream.

III. Event Probabilities 22 Feb-24 Feb

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

IV. Penticton 10.7 cm Flux

• Observed 21 Feb 098
• Predicted 22 Feb-24 Feb 095/090/090
• 90 Day Mean 21 Feb 117

V. Geomagnetic A Indices

• Observed Afr/Ap 20 Feb 002/004
• Estimated Afr/Ap 21 Feb 006/010
• Predicted Afr/Ap 22 Feb-24 Feb 010/012-010/012-008/010

VI. Geomagnetic Activity Probabilities 22 Feb-24 Feb

A. Middle Latitudes

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

B. High Latitudes

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