Joint USAF/NOAA Report of Solar and Geophysical Activity 21 Nov 2007

Product: Report of Solar-Geophysical Activity
Issued: 2007 Nov 21 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 325 Issued at 2200Z on 21 Nov 2007

IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity was very low. No flares were detected. The visible disk remained spotless.

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

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: Geomagnetic field activity ranged from quiet to active levels. ACE solar wind measurements indicated Earth remained under the influence of a recurrent coronal hole high-speed stream. Solar wind velocities gradually increased during the first half of the period and reached a peak of 703 km/sec at 21/0920Z, then gradually decreased to a low of 601 km/sec by the end of the period.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to active levels on 22 November as coronal hole effects continue. Activity is expected to decrease to quiet to unsettled levels on 23 November as coronal hole effects subside. Quiet conditions are expected on the final day of the period.

III. Event Probabilities 22 Nov-24 Nov

• Class M 01/01/01
• Class X 01/01/01
• Proton 01/01/01
• PCAF green

IV. Penticton 10.7 cm Flux

• Observed 21 Nov 069
• Predicted 22 Nov-24 Nov 069/069/068
• 90 Day Mean 21 Nov 068

V. Geomagnetic A Indices

• Observed Afr/Ap 20 Nov 010/028
• Estimated Afr/Ap 21 Nov 012/020
• Predicted Afr/Ap 22 Nov-24 Nov 012/015-008/010-005/008

VI. Geomagnetic Activity Probabilities 22 Nov-24 Nov

A. Middle Latitudes

• Active 30/20/10
• Minor storm 15/05/01
• Major-severe storm 05/01/01

B. High Latitudes

• Active 40/25/15
• Minor storm 20/10/05
• Major-severe storm 05/01/01