Report of Solar-Geophysical Activity

Issued: 2006 Mar 21 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 080 Issued at 2200Z on 21 Mar 2006 IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity was low. Region 862 (S07W39) produced five low level C-class flares; the largest of which was a C2.5 that occurred at 21/0944 UTC. Region 862 has shown little change in area over the last 24 hours and maintains a beta gamma magnetic configuration.

IB. Solar Activity Forecast: Solar activity is expected to be low with a slight chance for an M-class flare from Region 862.

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z:

The geomagnetic field was quiet to active. Isolated active periods were due to continued effects of a coronal hole high speed stream.

The greater than 2 MeV electron flux at geosynchronous orbit reached high levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled on 22 and 23 March. On 24 March, quiet to unsettled conditions with possible isolated active levels are expected as a coronal hole high speed stream moves into geoeffective position.

III. Event Probabilities 22 Mar-24 Mar

Class M 10/10/10

Class X 01/01/01

Proton 01/01/01

PCAF green

IV. Penticton 10.7 cm Flux

Observed 21 Mar 077

Predicted 22 Mar-24 Mar 080/080/080

90 Day Mean 21 Mar 080

V. Geomagnetic A Indices

Observed Afr/Ap 20 Mar 014/022

Estimated Afr/Ap 21 Mar 012/010

Predicted Afr/Ap 22 Mar-24 Mar 008/008-005/008-008/012 VI. Geomagnetic Activity Probabilities 22 Mar-24 Mar A. Middle Latitudes

Active 20/15/20

Minor storm 10/05/10

Major-severe storm 01/01/01

B. High Latitudes

Active 20/20/30

Minor storm 10/10/15

Major-severe storm 01/01/05