Joint USAF/NOAA Report of Solar and Geophysical Activity 18 Oct 2007

Product: Report of Solar-Geophysical Activity
Issued: 2007 Oct 18 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 291 Issued at 2200Z on 18 Oct 2007

IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity was very low. The visible disk remains spotless.

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

IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field began the summary period at quiet levels and became briefly active between 09-12Z as a recurrent coronal hole high speed stream became geoeffective. Activity since 12Z has been quiet to unsettled.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to range from unsettled to active for the next three days under the continued influence of the high speed stream.

III. Event Probabilities 19 Oct-21 Oct

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

IV. Penticton 10.7 cm Flux

• Observed 18 Oct 068
• Predicted 19 Oct-21 Oct 067/067/067
• 90 Day Mean 18 Oct 068

V. Geomagnetic A Indices

• Observed Afr/Ap 17 Oct 000/001
• Estimated Afr/Ap 18 Oct 010/010
• Predicted Afr/Ap 19 Oct-21 Oct 010/015-012/012-010/008

VI. Geomagnetic Activity Probabilities 19 Oct-21 Oct

A. Middle Latitudes

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

B. High Latitudes

• Active 35/26/15
• Minor storm 15/14/10
• Major-severe storm 10/05/01