Joint USAF/NOAA Report of Solar and Geophysical Activity 23 Aug 2002

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 235 Issued at 2200Z on 23 Aug 2002

IA.  Analysis of Solar Active Regions and Activity from  22/2100Z

to 23/2100Z:  Solar activity has been high.  There have been numerous

low level M-class events during the period from Regions 69 (S08W85),

83 (S19W15), 85 (S09E16) and 87 (S07E60).  The most impressive was

an M1/2n at 23/0549 UTC from Region 85 with an associated Type II

radio sweep.  A Type IV radio sweep was observed among several

reported events at 23/1415 UTC.  New Region 88 (S22W28) was numbered

today.
IB.  Solar Activity Forecast:  Solar activity is expected to be

moderate to high.  Regions 69, 83, 85, and 87 all have potential to

produce a major flare.
IIA.  Geophysical Activity Summary 22/2100Z to 23/2100Z:

The geomagnetic field has been quiet to unsettled.  The greater than

10 MeV proton event that began at 22/0440 UTC ended at 23/0040 UTC.

The event reached a maximum of 36 pfu at 22/0940 UTC.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is

expected to be unsettled to active on 24-25 August as a possible

result of the M5 event observed at 22/0157 UTC.  Quiet to unsettled

conditions are expected for 26 August.
III.  Event Probabilities 24 Aug-26 Aug

Class M    75/75/75

Class X    20/20/20

Proton     20/20/20

PCAF       yellow
IV.  Penticton 10.7 cm Flux

Observed           23 Aug 225

Predicted   24 Aug-26 Aug  215/210/210

90 Day Mean        23 Aug 170
V.  Geomagnetic A Indices

Observed Afr/Ap 22 Aug  008/011

Estimated Afr/Ap 23 Aug  008/008

Predicted Afr/Ap 24 Aug-26 Aug  020/025-015/015-010/010
VI.  Geomagnetic Activity Probabilities 24 Aug-26 Aug

A.  Middle Latitudes

Active                35/30/20

Minor storm           15/15/05

Major-severe storm    05/05/01

B.  High Latitudes

Active                40/35/25

Minor storm           20/20/10

Major-severe storm    10/10/01