Joint USAF/NOAA Report of Solar and Geophysical Activity 25 May 2005
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2005 May 25 2210 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 145 Issued at 2200Z on 25 May 2005
IA. Analysis of Solar Active Regions and Activity from 24/2100Z
to 25/2100Z: Solar activity continues at very low levels. Occasional
B-class flares were observed in Regions 766 (N14E23) and 767
(S07E26). These two active regions are the only sunspot groups on
the visible disk, and exhibited little change this period. A large
CME off the east limb was observed on LASCO imagery during the
latter half of 24 May. The likely source of this CME was backsided.
IB. Solar Activity Forecast: Solar activity is expected to continue
at very low levels. There is a slight chance for a C-class flare
from Region 767.
IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z:
The geomagnetic field was quiet. Solar wind speed declined to near
360 km/s. The greater than 2 MeV electron flux at geosynchronous
orbit was at high levels.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet, with isolated unsettled periods on 26 May.
Occasional active periods are expected on 27 and 28 May as a coronal
hole high speed stream rotates into a geoeffective position.
III. Event Probabilities 26 May-28 May
- Class M 05/05/05
- Class X 01/01/01
- Proton 01/01/01
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 25 May 084
- Predicted 26 May-28 May 085/085/095
- 90 Day Mean 25 May 090
V. Geomagnetic A Indices
- Observed Afr/Ap 24 May 002/005
- Estimated Afr/Ap 25 May 005/005
- Predicted Afr/Ap 26 May-28 May 005/010-010/015-015/020
VI. Geomagnetic Activity Probabilities 26 May-28 May
A. Middle Latitudes
- Active 15/20/30
- Minor storm 05/10/15
- Major-severe storm 01/01/05
B. High Latitudes
- Active 20/40/50
- Minor storm 10/20/25
- Major-severe storm 01/05/10
