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

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 204 Issued at 2200Z on 23 Jul 2002

IA.  Analysis of Solar Active Regions and Activity from  22/2100Z
to 23/2100Z:  Solar activity was high.  Region 39 (S15E59) produced
an X4/2b event at 23/0035 UTC with associated Type II and Type IV
radio sweeps and an 1800 sfu Tenflare.  A full-halo CME was visible
in the SOHO/LASCO imagery with this event.  This region now exceeds
900 millionths of white light area with a magnetic delta
configuration.  Another region of interest is Region 36 (S07W28). 
It also exceeds 900 millionths of white light with a magnetic
beta-gamma configuration.  Two new regions were numbered today as
Regions 43 (N12E56) and 44 (S19E57).

IB.  Solar Activity Forecast:  Solar activity is expected to be
moderate to high.  Regions 36 and 39 both have potential to produce
isolated major events.

IIA.  Geophysical Activity Summary 22/2100Z to 23/2100Z:
The geomagnetic field has been quiet to unsettled.  Isolated active
to minor storm conditions were observed at high latitudes.  The
greater than 10 MeV proton event which began at 22/0655 UTC
continues with the tentative maximum of 28 pfu at 23/1025 UTC.  The
energetic electron fluxes at geosynchronous orbit were at high
levels today.

IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be quiet to active on 24 July.  Minor storm conditions
are expected on 25 July with active to minor conditions on 26 July. 
These conditions are anticipated due to the X-class event observed
today.  The greater than 10 MeV proton event is expected to continue
for most of the period.  The energetic electron fluxes at
geosynchronous orbit are expected to remain at high levels for the
next several days.

III.  Event Probabilities 24 Jul-26 Jul
Class M    75/75/75
Class X    25/25/25
Proton     99/99/99
PCAF       yellow

IV.  Penticton 10.7 cm Flux
Observed           23 Jul 198
Predicted   24 Jul-26 Jul  195/195/200
90 Day Mean        23 Jul 162

V.  Geomagnetic A Indices
Observed Afr/Ap 22 Jul  012/020
Estimated Afr/Ap 23 Jul  015/015
Predicted Afr/Ap 24 Jul-26 Jul  015/015-030/040-020/030

VI.  Geomagnetic Activity Probabilities 24 Jul-26 Jul
A.  Middle Latitudes
Active                25/40/30
Minor storm           05/30/15
Major-severe storm    01/10/05
B.  High Latitudes
Active                30/50/40
Minor storm           10/40/20
Major-severe storm    05/10/10