Joint USAF/NOAA Report of Solar and Geophysical Activity 15 Dec 2002

SDF Number 349 Issued at 2200Z on 15 Dec 2002

IA. Analysis of Solar Active Regions and Activity from 14/2100Z
to 15/2100Z: Solar activity was low. Numerous C-class events
occurred, with Region 226 (S28E25) being the most frequent source of
flare activity. However, Region 227 (N06E08) appeared in available
H-alpha and SOHO-EIT imagery to have been the source of the largest
event of the period, associated with an impulsive C5.9 x-ray
enhancement at 15/1804 UTC. Several other regions produced C-class
optical flares, including the closely spaced group of Regions
223/5/9 (collectively located near N20E45). Of these, Region 229
(N18E51) appears to be the largest and most complex. No new regions
were numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be
predominantly low, with a chance for isolated moderate flare
activity during the next three days.

IIA. Geophysical Activity Summary 14/2100Z to 15/2100Z:
The geomagnetic field was quiet to unsettled. Weak coronal hole high
speed stream effects persisted through the period.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled for the next two days. Isolated
active and minor storm conditions are possible on day three, in
response to expected recurrent coronal hole effects

III. Event Probabilities 16 Dec-18 Dec

• Class M 35/35/35
• Class X 01/01/01
• Proton 01/01/01
• PCAF green

IV. Penticton 10.7 cm Flux

• Observed 15 Dec 203
• Predicted 16 Dec-18 Dec 195/200/200
• 90 Day Mean 15 Dec 165

V. Geomagnetic A Indices

• Observed Afr/Ap 14 Dec 009/011
• Estimated Afr/Ap 15 Dec 007/010
• Predicted Afr/Ap 16 Dec-18 Dec 010/010-010/010-015/015

VI. Geomagnetic Activity Probabilities 16 Dec-18 Dec
A. Middle Latitudes

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

B. High Latitudes

• Active 15/20/35
• Minor storm 01/05/10
• Major-severe storm 01/01/01