Joint USAF/NOAA Report of Solar and Geophysical Activity 30 May 2003
SDF Number 150 Issued at 2200Z on 30 May 2003
IA. Analysis of Solar Active Regions and Activity from 29/2100Z
to 30/2100Z: Solar activity was low. Region 365 (S07W59) remains the
largest and most complex sunspot group on the disk with some decay
evident since yesterday. The largest flare in this region was a
C8/1n at 30/0650 UTC.
IB. Solar Activity Forecast: Solar activity is expected to moderate
to high. Region 365 remains capable of another major flare.
IIA. Geophysical Activity Summary 29/2100Z to 30/2100Z:
The geomagnetic field ranged from unsettled to severe storm levels.
The field was mostly unsettled to active since about 30/0600 UTC
with a single minor storm period from 30/1500-1800 UTC. The CME
associated with the X1 flare early on 29 May was apparently observed
to encounter the ACE spacecraft at about 30/1600 UTC. The shock in
solar wind parameters was not strong and an SI was not clearly
observed by ground magnetometers. The proton event at greater than
10 MeV has ended: 28/2335 UTC start, 121 pfu peak at 29/1530 UTC,
and 30/0110 UTC end.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to range from unsettled to minor storm levels as the
current CME passes.
III. Event Probabilities 31 May-02 Jun
- Class M 80/80/80
- Class X 20/20/20
- Proton 20/20/20
- PCAF yellow
IV. Penticton 10.7 cm Flux
- Observed 30 May 117
- Predicted 31 May-02 Jun 115/110/105
- 90 Day Mean 30 May 125
V. Geomagnetic A Indices
- Observed Afr/Ap 29 May 059/089
- Estimated Afr/Ap 30 May 035/060
- Predicted Afr/Ap 31 May-02 Jun 025/040-015/025-015/020
VI. Geomagnetic Activity Probabilities 31 May-02 Jun
A. Middle Latitudes
- Active 40/20/15
- Minor storm 30/10/05
- Major-severe storm 15/05/01
B. High Latitudes
- Active 20/50/50
- Minor storm 50/20/10
- Major-severe storm 30/10/01
