Report of Solar-Geophysical Activity

Issued: 2006 May 11 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 131 Issued at 2200Z on 11 May 2006 IA. Analysis of Solar Active Regions and Activity from 10/2100Z to 11/2100Z: Solar activity was very low. Region 882 (S12W82) remains the most magnetically complex sunspot group on the visible desk but has exhibited no growth or activity.

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

IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z:

The geomagnetic field has been unsettled to active. The large recurrent coronal hole high speed stream has rotated into a geoeffective position. Consequently, the solar wind speed increased to approximately 600 km/s.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to range from quiet to minor storm levels. Expect unsettled to active conditions with isolated minor storm periods on 12 May due to the coronal hole high speed stream. Quiet to unsettled conditions are expected on 13 and 14 May.

III. Event Probabilities 12 May-14 May

Class M 01/01/01

Class X 01/01/01

Proton 01/01/01

PCAF green

IV. Penticton 10.7 cm Flux

Observed 11 May 076

Predicted 12 May-14 May 075/075/075

90 Day Mean 11 May 082

V. Geomagnetic A Indices

Observed Afr/Ap 10 May 004/004

Estimated Afr/Ap 11 May 018/030

Predicted Afr/Ap 12 May-14 May 020/025-010/012-005/010 VI. Geomagnetic Activity Probabilities 12 May-14 May A. Middle Latitudes

Active 50/25/15

Minor storm 25/10/05

Major-severe storm 15/05/01

B. High Latitudes

Active 50/25/20

Minor storm 30/15/10

Major-severe storm 20/10/05