Joint USAF/NOAA Report of Solar and Geophysical Activity 22 May 2003

SDF Number 142 Issued at 2200Z on 22 May 2003

IA. Analysis of Solar Active Regions and Activity from 21/2100Z
to 22/2100Z: Solar activity was at low levels. Region 362 (S11W15)
produced a C4 flare at 0704Z. This region remains relatively
unchanged since yesterday. Region 362 has an east-west inversion
line and maintains its beta-gamma magnetic configuration. Three new
regions were numbered today: Region 366 (N11E62), Region 367
(S14E69), and Region 368 (S32E76).

IB. Solar Activity Forecast: Solar activity is expected to be low.
Regions 362 and 364 continue to have C-class potential.

IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z:
The geomagnetic field was at active to minor storm levels with one
period of quiet conditions. Solar wind speed decreased slightly
from yesterday but has remained elevated near 500 km/s due to a
coronal hole high speed stream.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at unsettled to active levels with a chance of minor
storming at local nighttime hours. Coronal hole high speed stream
effects are expected to continue through day two of the period.

III. Event Probabilities 23 May-25 May
Class M 15/15/10
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 22 May 118
Predicted 23 May-25 May 125/130/135
90 Day Mean 22 May 124

V. Geomagnetic A Indices
Observed Afr/Ap 21 May 013/020
Estimated Afr/Ap 22 May 025/027
Predicted Afr/Ap 23 May-25 May 020/020-015/020-012/015

VI. Geomagnetic Activity Probabilities 23 May-25 May
A. Middle Latitudes
Active 40/35/30
Minor storm 20/15/10
Major-severe storm 05/05/05
B. High Latitudes
Active 50/50/40
Minor storm 25/25/20
Major-severe storm 15/15/10