Report of Solar-Geophysical Activity

Issued: 2006 Mar 20 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 079 Issued at 2200Z on 20 Mar 2006 IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity was at very low levels. Region 862

(S07W27) continues to show growth in sunspot area and remains the only spotted region on the visible disk. Magnetic analysis depicts a weak gamma structure developing within the intermediate cluster of sunspots. Multiple B-class flares were observed from Region 862 during the period. No new regions were numbered today.

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

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z:

The geomagnetic field ranged from quiet to minor storm levels today.

The elevated conditions are due to a favorably positioned coronal hole. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels again today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels. Isolated active periods may be possible on 21 March due to a waning geoeffective high speed coronal hole stream.

III. Event Probabilities 21 Mar-23 Mar

Class M 01/01/01

Class X 01/01/01

Proton 01/01/01

PCAF green

IV. Penticton 10.7 cm Flux

Observed 20 Mar 077

Predicted 21 Mar-23 Mar 075/075/075

90 Day Mean 20 Mar 080

V. Geomagnetic A Indices

Observed Afr/Ap 19 Mar 024/037

Estimated Afr/Ap 20 Mar 020/018

Predicted Afr/Ap 21 Mar-23 Mar 010/012-005/005-005/005 VI. Geomagnetic Activity Probabilities 21 Mar-23 Mar A. Middle Latitudes

Active 20/15/15

Minor storm 10/05/05

Major-severe storm 01/01/01

B. High Latitudes

Active 30/15/15

Minor storm 10/05/05

Major-severe storm 05/01/01