Joint USAF/NOAA Report of Solar and Geophysical Activity 07-22-2002

:Product: Report of Solar-Geophysical Activity

:Issued: 2002 Jul 21 2210 UTC

# Prepared jointly by the U.S. Dept. of Commerce, NOAA,

#Space Environment Center and the U.S. Air Force.

#

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 202 Issued at 2200Z on 21 Jul 2002

IA.  Analysis of Solar Active Regions and Activity from  20/2100Z

to 21/2100Z:  Solar activity was high. The event in progress at issue

time yesterday, from behind the east limb near S10, reached  the X3

level at 20/2130UTC. There was an associated type II sweep and

tenflare. The site of the activity has, as yet, failed to fully

appear, but should do so in the next 24 hours. Some plage and

faculae are now visible in that vicinity. Elsewhere, Regions 30

(N18W76) and 36 (S06W02) continue to impress in white light and

H-alpha, but have been relatively quiet. One new region, 38

(N17E51), was assigned.

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

moderate. Watch the east limb for more energetic activity over the

next three days.

IIA.  Geophysical Activity Summary 20/2100Z to 21/2100Z:

The geomagnetic field was at quiet to minor storm levels during the

period. Faster than normal solar wind, with some southward Bz,

brought periods of minor storm conditions to local nighttime

sectors. An enhancement in the greater than 10 MeV protons has

occurred, with current readings near 5 pfu. The greater than 2 MeV

electrons at geosynchronous orbit reached high levels for a few

hours near midday.

IIB.  Geophysical Activity Forecast:  The geomagnetic field is

expected to be unsettled to mildly active for the next three days.

III.  Event Probabilities 22 Jul-24 Jul

Class M    70/70/70

Class X    20/20/20

Proton     20/20/20

PCAF       yellow

IV.  Penticton 10.7 cm Flux

Observed           21 Jul 183

Predicted   22 Jul-24 Jul  185/185/185

90 Day Mean        21 Jul 161

V.  Geomagnetic A Indices

Observed Afr/Ap 20 Jul  013/018

Estimated Afr/Ap 21 Jul  015/018

Predicted Afr/Ap 22 Jul-24 Jul  010/012-010/010-010/010

VI.  Geomagnetic Activity Probabilities 22 Jul-24 Jul

A.  Middle Latitudes

Active                30/30/30

Minor storm           15/15/15

Major-severe storm    05/05/05

B.  High Latitudes

Active                40/40/40

Minor storm           15/15/15

Major-severe storm    05/05/05