Report of Solar-Geophysical Activity

Issued: 2006 Jul 27 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 208 Issued at 2200Z on 27 Jul 2006 IA. Analysis of Solar Active Regions and Activity from 26/2100Z to 27/2100Z: Solar activity continues at very low levels. Region 901 (N05E00), the only sunspot group on the visible disk, produced occasional low B-class flares. Considerable decay was observed in the trailing sunspots in this region; however, new negative flux emerged northwest of the leader spot. This location was the source of most of the B-class flares.

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

IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z:

The geomagnetic field was quiet. Solar wind speed increased gradually from 330 km/s to near 450 km/s by the end of the period. This increase is associated with a weak high speed coronal hole stream.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet with isolated unsettled periods.

III. Event Probabilities 28 Jul-30 Jul

Class M 01/01/01

Class X 01/01/01

Proton 01/01/01

PCAF green

IV. Penticton 10.7 cm Flux

Observed 27 Jul 074

Predicted 28 Jul-30 Jul 075/075/075

90 Day Mean 27 Jul 078

V. Geomagnetic A Indices

Observed Afr/Ap 26 Jul 005/006

Estimated Afr/Ap 27 Jul 005/005

Predicted Afr/Ap 28 Jul-30 Jul 005/005-005/005-005/005 VI. Geomagnetic Activity Probabilities 28 Jul-30 Jul A. Middle Latitudes

Active 15/15/15

Minor storm 05/05/05

Major-severe storm 01/01/01

B. High Latitudes

Active 20/20/20

Minor storm 05/05/05

Major-severe storm 01/01/01