Report of Solar-Geophysical Activity

Report of Solar-Geophysical Activity

Issued: 2008 Feb 18 2200 UTC

Prepared jointly by the U.S. Dept. of Commerce, NOAA,

Space Weather Prediction Center and the U.S. Air Force.

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 049 Issued at 2200Z on 18 Feb 2008

IA. Analysis of Solar Active Regions and Activity from 17/2100Z

to 18/2100Z: Solar activity was at very low levels. The visible

solar disk remained spotless.

IB. Solar Activity Forecast: Solar activity is expected to remain

at very low levels.

IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z:

The geomagnetic field was at mostly quiet to unsettled levels. An

isolated active period was observed from 18/0900 - 1200Z due to

sustained southward Bz (-5nT maximum) and elevated solar wind speed.

Beginning at approximately 18/0600Z wind speed began a gradual rise

from around 450 km/s to end the summary period at about 600 km/s.

IIB. Geophysical Activity Forecast: The geomagnetic field is

expected to be at quiet to unsettled levels for the forecast period

(19 - 21 February).

III. Event Probabilities 19 Feb-21 Feb

Class M 01/01/01

Class X 01/01/01

Proton 01/01/01

PCAF Green

IV. Penticton 10.7 cm Flux

Observed 18 Feb 071

Predicted 19 Feb-21 Feb 070/070/070

90 Day Mean 18 Feb 075

V. Geomagnetic A Indices

Observed Afr/Ap 17 Feb 003/005

Estimated Afr/Ap 18 Feb 008/010

Predicted Afr/Ap 19 Feb-21 Feb 008/008-005/005-008/008

VI. Geomagnetic Activity Probabilities 19 Feb-21 Feb

A. Middle Latitudes

Active 10/05/10

Minor storm 05/01/05

Major-severe storm 01/01/01

B. High Latitudes

Active 15/10/15

Minor storm 10/05/10

Major-severe storm 05/01/05