Report of Solar-Geophysical Activity
Issued: 2006 Apr 14 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 104 Issued at 2200Z on 14 Apr 2006 IA. Analysis of Solar Active Regions and Activity from 13/2100Z to 14/2100Z: Solar activity remained very low. No significant flares occurred during the past 24 hours.
IB. Solar Activity Forecast: Solar activity is expected to be at very low to low levels.
IIA. Geophysical Activity Summary 13/2100Z to 14/2100Z:
The geomagnetic field ranged from quiet to major storm levels. An interval of major to severe storm conditions was observed at the Boulder magnetometer between 14/0600Z and 1200Z. The interplanetary magnetic field strengthened, and the Z-component rotated smoothly from 13/1500Z through 14/1200Z from 17 nT through a maximum negative value of -15 nT. Solar wind speeds ranged from approximately 480 km/s to 570 km/s. The unusual solar wind conditions appear to be consistent with a corotating interaction region that may have been complicated by the presence of transient flow. 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 unsettled to active. Isolated periods of minor to major storm conditions are possible on 15-16 April due to a coronal hole high speed stream. Predominantly unsettled conditions will return on 17 April.
III. Event Probabilities 15 Apr-17 Apr
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 14 Apr 079
Predicted 15 Apr-17 Apr 080/080/080
90 Day Mean 14 Apr 080
V. Geomagnetic A Indices
Observed Afr/Ap 13 Apr 009/013
Estimated Afr/Ap 14 Apr 032/040
Predicted Afr/Ap 15 Apr-17 Apr 025/030-020/025-015/015 VI. Geomagnetic Activity Probabilities 15 Apr-17 Apr A. Middle Latitudes
Active 35/30/25
Minor storm 25/20/15
Major-severe storm 10/10/05
B. High Latitudes
Active 40/35/30
Minor storm 25/25/20
Major-severe storm 15/10/10