Joint USAF/NOAA Report of Solar and Geophysical Activity 20 Nov 2007

Product: Report of Solar-Geophysical Activity
Issued: 2007 Nov 20 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 324 Issued at 2200Z on 20 Nov 2007

IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity was at very low levels. The visible solar disk remained spotless.

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

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field was at quiet to major storm levels. An isolated period of major storm conditions was observed from 20/1200 – 1500Z. Continued influence from a co-rotating interaction region and coronal hole high speed stream was seen by the ACE spacecraft through the summary interval. Solar wind speed ranged from approximately 440 km/s to a maximum of 510 km/s with Bz varying from +10nT to -16nT during the summary period.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels. On day one and two (21 and 22 November), activity should remain at unsettled to active levels. Isolated minor storm periods at middle latitudes and major storm levels at high latitudes are possible due to the continued effects from the coronal hole high speed stream. Activity levels should decrease to quiet to unsettled conditions on 23 November.

III. Event Probabilities 21 Nov-23 Nov

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

IV. Penticton 10.7 cm Flux

• Observed 20 Nov 070
• Predicted 21 Nov-23 Nov 070/070/069
• 90 Day Mean 20 Nov 068

V. Geomagnetic A Indices

• Observed Afr/Ap 19 Nov 002/003
• Estimated Afr/Ap 20 Nov 025/025
• Predicted Afr/Ap 21 Nov-23 Nov 018/020-015/015-008/010

VI. Geomagnetic Activity Probabilities 21 Nov-23 Nov

A. Middle Latitudes

• Active 35/30/15
• Minor storm 15/15/05
• Major-severe storm 10/10/01

B. High Latitudes

• Active 40/35/20
• Minor storm 20/20/15
• Major-severe storm 15/15/10