Joint USAF/NOAA Report of Solar and Geophysical Activity 31 May 2003
SDF Number 151 Issued at 2200Z on 31 May 2003
IA. Analysis of Solar Active Regions and Activity from 30/2100Z
to 31/2100Z: Solar activity was high. Region 365 (S07W72) produced
an M9/2b flare at 31/0224 UTC. The flare was accompanied by a 1300
sfu radio burst at 2695 MHz, a Type II radio sweep, and a CME
observed by the SOHO spacecraft to be directed mostly towards the
southwest. This region also generated a few C-class subflares during
the past day. Further decay, mostly in penumbral area, is evident
since yesterday.
IB. Solar Activity Forecast: Solar activity is expected to be
moderate to high. Region 365 may produce yet another major flare
before it passes the west solar limb.
IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z:
The geomagnetic field ranged from quiet to major storm levels. The
most disturbed period occurred from 31/0300-0600 UTC and has since
been quiet to unsettled at most locations. A greater than 10 MeV
proton event started at 31/0440 UTC, reached a 27 pfu peak at
31/0645 UTC, and ended at 31/1440 UTC.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be mostly unsettled to active with a chance of isolated
storm conditions at local nighttime. The field may become
increasingly disturbed by 03 June due to a recurrent coronal hole
high-speed stream.
III. Event Probabilities 01 Jun-03 Jun
- Class M 80/50/10
- Class X 20/10/01
- Proton 20/10/01
- PCAF yellow
IV. Penticton 10.7 cm Flux
- Observed 31 May 113
- Predicted 01 Jun-03 Jun 110/100/090
- 90 Day Mean 31 May 125
V. Geomagnetic A Indices
- Observed Afr/Ap 30 May 036/049
- Estimated Afr/Ap 31 May 025/040
- Predicted Afr/Ap 01 Jun-03 Jun 015/025-015/015-020/030
VI. Geomagnetic Activity Probabilities 01 Jun-03 Jun
A. Middle Latitudes
- Active 20/15/30
- Minor storm 10/05/05
- Major-severe storm 05/01/01
B. High Latitudes
- Active 50/30/60
- Minor storm 20/05/05
- Major-severe storm 10/01/01
