Joint USAF/NOAA Report of Solar and Geophysical Activity 14 Apr 2006

Product: 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