Report of Solar-Geophysical Activity

Issued: 2005 Oct 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 293 Issued at 2200Z on 20 Oct 2005 IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity was very low. No flares were observed during the past 24 hours.

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

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

The geomagnetic field was quiet. The greater than 2 MeV electron flux reached high levels during the past 24 hours.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet on 21 Oct. Unsettled conditions, with a chance for active periods, are expected for 22-23 Oct, due to a favorably positioned coronal hole.

III. Event Probabilities 21 Oct-23 Oct

Class M 01/01/01

Class X 01/01/01

Proton 01/01/01

PCAF green

IV. Penticton 10.7 cm Flux

Observed 20 Oct 077

Predicted 21 Oct-23 Oct 078/078/078

90 Day Mean 20 Oct 088

V. Geomagnetic A Indices

Observed Afr/Ap 19 Oct 003/007

Estimated Afr/Ap 20 Oct 005/008

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

Active 15/20/20

Minor storm 10/15/15

Major-severe storm 01/05/05

B. High Latitudes

Active 15/25/25

Minor storm 10/20/20

Major-severe storm 01/10/10