Joint USAF/NOAA Report of Solar and Geophysical Activity 18 Apr 2006

Product: Report of Solar-Geophysical Activity
Issued: 2006 Apr 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 108 Issued at 2200Z on 18 Apr 2006

IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity remained at very low levels. A small filament eruption occurred early in the period and a related CME was observed on LASCO imagery shortly there after. The CME does not appear to be Earth directed. Region 874 (N00E15) was numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be at very low levels.

IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field was at quiet to unsettled levels. The greater than 2 MeV electron flux at geosynchronous orbit reached very high levels again today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels.

III. Event Probabilities 19 Apr-21 Apr

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

IV. Penticton 10.7 cm Flux

• Observed 18 Apr 074
• Predicted 19 Apr-21 Apr 075/075/075
• 90 Day Mean 18 Apr 078

V. Geomagnetic A Indices

• Observed Afr/Ap 17 Apr 004/006
• Estimated Afr/Ap 18 Apr 005/008
• Predicted Afr/Ap 19 Apr-21 Apr 005/008-005/008-005/008

VI. Geomagnetic Activity Probabilities 19 Apr-21 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 01/01/01