Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 05 Apr 2008

By SpaceRef Editor

April 5, 2008

Filed under Earth, Space Weather Prediction Center (NOAA), Space Weather Solar-Geophysical Activity, US

Product: Report of Solar-Geophysical Activity
Issued: 2008 Apr 05 2200 UTC
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Weather Prediction Center and the U.S. Air Force.

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 096 Issued at 2200Z on 05 Apr 2008

IA. Analysis of Solar Active Regions and Activity from 04/2100Z to 05/2100Z: Solar activity was very low. Spotless plage Region 989 (S11W67) produced an isolated low-level B-class flare. SOHO/LASCO images showed a halo CME, first visible in C2 at 05/1626Z. The CME appeared to be from the back side, based on STEREO Ahead EUVI 195 images and the GOES- 10 X-ray signature. No new active regions were numbered.

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

IIA. Geophysical Activity Summary 04/2100Z to 05/2100Z: Geomagnetic field activity ranged from quiet to major storm levels with a Kp = 6 observed during 05/1500 – 1800Z. ACE measurements indicated Earth entered a fast solar wind flow from a recurrent low-latitude coronal hole in the southern hemisphere. Solar wind velocities increased during the period with a peak of 671 km/sec detected at 05/1634Z. IMF Bz reached a minimum of -7 nT at 05/1441Z. The greater than 2 MeV electron flux at geosynchronous orbit briefly reached high levels during the period.

IIB. Geophysical Activity Forecast: Geomagnetic field activity is expected to be at unsettled to minor storm levels on day 1 (06 April) with major storm levels possible at high latitudes. Activity is expected to decrease to unsettled to active levels during days 2 – 3 (07 – 08 April) as coronal hole effects persist.

III. Event Probabilities 06 Apr-08 Apr