Joint USAF/NOAA Report of Solar and Geophysical Activity 25 Nov 2004

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.

Updated 2004 Nov 25 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 330 Issued at 2200Z on 25 Nov 2004

IA. Analysis of Solar Active Regions and Activity from 24/2100Z
to 25/2100Z: Solar activity was low. The largest C-class event of
the period was a C9/Sf flare at 24/2145 UTC from Region 706
(S08E56).

IB. Solar Activity Forecast: Solar activity is expected to be low
with a slight chance of an isolated M-class event.

IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z:
The geomagnetic field was quiet to active with one period at 25/0600
UTC of minor storm conditions at high latitudes. Solar wind speed
at ACE has steadily increased during the last 24 hours from around
380 to 550 km/s. This increase is likely due to the recurrent
coronal hole. Prolonged periods of southward Bz components were
responsible for the minor storming conditions.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled. Isolated active conditions are
possible for 26 November as the geomagnetic field continues to be
under the influence of the coronal hole high speed stream.

III. Event Probabilities 26 Nov-28 Nov

• Class M 15/15/15
• Class X 01/01/01
• Proton 01/01/01
• PCAF green

IV. Penticton 10.7 cm Flux

• Observed 25 Nov 109
• Predicted 26 Nov-28 Nov 110/115/115
• 90 Day Mean 25 Nov 106

V. Geomagnetic A Indices

• Observed Afr/Ap 24 Nov 007/006
• Estimated Afr/Ap 25 Nov 012/020
• Predicted Afr/Ap 26 Nov-28 Nov 010/015-008/010-005/005

VI. Geomagnetic Activity Probabilities 26 Nov-28 Nov

A. Middle Latitudes

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

B. High Latitudes

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