Report of Solar-Geophysical Activity

Report of Solar-Geophysical Activity

Issued: 2008 May 22 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 143 Issued at 2200Z on 22 May 2008

IA. Analysis of Solar Active Regions and Activity from 21/2100Z

to 22/2100Z: Solar activity was very low. The visible disk is

spotless. A 10 degree filament near S25E08 disappeared between

0734-1338Z.

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

low.

IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z:

The geomagnetic field was quiet to unsettled. Solar wind speed

decreased gradually from approximately 620 km/s to values ranging

between 580 - 520 km/s. The solar wind signatures were consistent

with a high speed stream from a coronal hole.

IIB. Geophysical Activity Forecast: The geomagnetic field is

expected to be quiet to unsettled with a chance for isolated active

periods for the next three days (23 - 25 May) due to persistent

effects from the high speed stream.

III. Event Probabilities 23 May-25 May

Class M 01/01/01

Class X 01/01/01

Proton 01/01/01

PCAF Green

IV. Penticton 10.7 cm Flux

Observed 22 May 069

Predicted 23 May-25 May 068/068/068

90 Day Mean 22 May 071

V. Geomagnetic A Indices

Observed Afr/Ap 21 May 009/013

Estimated Afr/Ap 22 May 010/010

Predicted Afr/Ap 23 May-25 May 008/010-008/010-008/010

VI. Geomagnetic Activity Probabilities 23 May-25 May

A. Middle Latitudes

Active 25/25/25

Minor storm 10/10/10

Major-severe storm 01/01/01

B. High Latitudes

Active 40/40/25

Minor storm 20/20/15

Major-severe storm 10/10/05