Joint USAF/NOAA Report of Solar and Geophysical Activity 16 Apr 2005

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2005 Apr 16 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 106 Issued at 2200Z on 16 Apr 2005

IA. Analysis of Solar Active Regions and Activity from 15/2100Z
to 16/2100Z: Solar activity has been very low. Current active
regions on the solar disk remain steady, with no new regions
numbered today.

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

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

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to remain at quiet to unsettled levels through 19 Apr.

III. Event Probabilities 17 Apr-19 Apr

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

IV. Penticton 10.7 cm Flux

• Observed 16 Apr 083
• Predicted 17 Apr-19 Apr 085/085/085
• 90 Day Mean 16 Apr 093

V. Geomagnetic A Indices

• Observed Afr/Ap 15 Apr 007/013
• Estimated Afr/Ap 16 Apr 005/008
• Predicted Afr/Ap 17 Apr-19 Apr 005/005-005/005-005/005

VI. Geomagnetic Activity Probabilities 17 Apr-19 Apr

A. Middle Latitudes

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

B. High Latitudes

• Active 20/20/20
• Minor storm 05/05/05
• Major-severe storm 02/02/02