Joint USAF/NOAA Report of Solar and Geophysical Activity 16 Dec 2003

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

Updated 2003 Dec 16 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 350 Issued at 2200Z on 16 Dec 2003

IA. Analysis of Solar Active Regions and Activity from 15/2100Z
to 16/2100Z: Solar activity has been low.

IB. Solar Activity Forecast: Solar activity is expected to be low
through 19 Dec.

IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z:
The geomagnetic field has been at quiet to unsettled levels. The
greater than 2MeV electron flux at geosynchronous orbit reached high
levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels for 17 – 18 Dec. By 19
Dec, a high-speed stream should begin to impact the Earth’s magnetic
field, elevating the geomagnetic field to active to minor storm
levels.

III. Event Probabilities 17 Dec-19 Dec

• Class M 05/05/05
• Class X 01/01/01
• Proton 01/01/01
• PCAF green

IV. Penticton 10.7 cm Flux

• Observed 16 Dec 106
• Predicted 17 Dec-19 Dec 110/110/115
• 90 Day Mean 16 Dec 136

V. Geomagnetic A Indices

• Observed Afr/Ap 15 Dec 018/025
• Estimated Afr/Ap 16 Dec 012/013
• Predicted Afr/Ap 17 Dec-19 Dec 012/012-010/012-018/018

VI. Geomagnetic Activity Probabilities 17 Dec-19 Dec

A. Middle Latitudes

• Active 35/35/30
• Minor storm 10/10/20
• Major-severe storm 01/01/10

B. High Latitudes

• Active 35/35/30
• Minor storm 15/15/25
• Major-severe storm 01/01/05