Joint USAF/NOAA Report of Solar and Geophysical Activity 01 Sep 2007

Product: Report of Solar-Geophysical Activity
Issued: 2007 Sep 01 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 244 Issued at 2200Z on 01 Sep 2007
IA. Analysis of Solar Active Regions and Activity from 31/2100Z to 01/2100Z: Solar activity was very low. No flares were observed during the past 24 hours. New Region 970 (S06W07) was assigned today and is a small, C-type sunspot group. A filament eruption on the west limb was observed beginning at about 31/2000Z in Stereo-A EUVI images and was later seen as a limb CME in the Stereo-A COR1 and COR2 coronagraphs just after 01/0000Z.
IB. Solar Activity Forecast: Solar activity is expected to be very low.
IIA. Geophysical Activity Summary 31/2100Z to 01/2100Z: The geomagnetic field was mostly quiet to unsettled. There was an isolated active period from 0900-1200Z. Real-time solar wind measurements at the ACE spacecraft show a slow increase in speed over the last 24 hours, from initial values around 420 km/s to about 520 km/s by forecast issue time. The increase is consistent with a high speed stream from a favorably positioned coronal hole. The greater than 2 MeV electron flux at geosynchronous orbit was at high levels from 31/2100-31/2115 but was dropped below 1000 PFU for the remainder of the period.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be unsettled to active for the next 24 hours (02 September) as the high speed solar wind stream is expected to continue. Conditions should subside to mostly unsettled for the second day (03 September), and should be quiet to unsettled by the third day (04 September).
III. Event Probabilities 02 Sep-04 Sep
- Class M 01/01/01
- Class X 01/01/01
- Proton 01/01/01
- PCAF Green
IV. Penticton 10.7 cm Flux
- Observed 01 Sep 071
- Predicted 02 Sep-04 Sep 071/070/070
- 90 Day Mean 01 Sep 071
V. Geomagnetic A Indices
- Observed Afr/Ap 31 Aug 007/007
- Estimated Afr/Ap 01 Sep 015/015
- Predicted Afr/Ap 02 Sep-04 Sep 013/020-010/012-005/008
VI. Geomagnetic Activity Probabilities 02 Sep-04 Sep
A. Middle Latitudes
- Active 35/35/15
- Minor storm 15/15/05
- Major-severe storm 05/05/01
B. High Latitudes
- Active 35/30/15
- Minor storm 20/15/05
- Major-severe storm 10/10/01