Report of Solar-Geophysical Activity

Issued: 2006 Apr 16 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 106 Issued at 2200Z on 16 Apr 2006 IA. Analysis of Solar Active Regions and Activity from 15/2100Z to 16/2100Z: Solar activity was very low. Region 871 (S06W33) produced a B1 flare at 16/1829Z.

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

IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z:

The geomagnetic field ranged from quiet to active. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled. Isolated active periods are possible early on 17 April.

III. Event Probabilities 17 Apr-19 Apr

Class M 01/01/01

Class X 01/01/01

Proton 01/01/01

PCAF green

IV. Penticton 10.7 cm Flux

Observed 16 Apr 077

Predicted 17 Apr-19 Apr 075/075/075

90 Day Mean 16 Apr 080

V. Geomagnetic A Indices

Observed Afr/Ap 15 Apr 018/029

Estimated Afr/Ap 16 Apr 010/015

Predicted Afr/Ap 17 Apr-19 Apr 008/008-005/008-005/008 VI. Geomagnetic Activity Probabilities 17 Apr-19 Apr A. Middle Latitudes

Active 15/10/10

Minor storm 05/05/05

Major-severe storm 01/01/01

B. High Latitudes

Active 20/20/20

Minor storm 05/05/05

Major-severe storm 01/01/01