Joint USAF/NOAA Report of Solar and Geophysical Activity 3 Aug 2002

:Product: Report of Solar-Geophysical Activity

:Issued: 2002 Aug 03 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 215 Issued at 2200Z on 03 Aug 2002

IA.  Analysis of Solar Active Regions and Activity from  02/2100Z

to 03/2100Z:  Solar activity was high. Region 39 (S16W83) produced an

impulsive X1 flare and CME off the SW limb at 23/1907Z. Limb

proximity limits our analysis of this region, but it was in a decay

phase over the past few days. Complex Region 44 (S24W88) produced

considerable surging early in the period and is the likely source of

a C6 flare in progress at issue time. Some development in size and

complexity was observed in Region 57 (S08W25) which now exhibits a

beta-gamma configuration. Region 50 (S08W73) continues to maintain

moderate size and complexity, but has been quiet. New Regions 60

(S28W26), and 61 (N08E77) were numbered today.

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

moderate. M-class flares are still possible from Regions 39 and 44

as they rotate around the west limb. M-class flares are also

possible from Region 50 and developing Region 57. An isolated major

flare is possible.

IIA.  Geophysical Activity Summary 02/2100Z to 03/2100Z:

The geomagnetic field was at quiet to minor storm levels. Active to

minor storm conditions were observed through the first half of the

period but tapered off to quiet to unsettled after 23/0900Z.

IIB.  Geophysical Activity Forecast:  The geomagnetic field is

expected to continue at mostly quiet to unsettled levels with

isolated high latitude active periods. Preliminary analysis of the

X1 flare and CME off the SW limb late today suggests the ejecta is

not earthbound.

III.  Event Probabilities 04 Aug-06 Aug

Class M    75/65/55

Class X    20/15/10

Proton     20/15/05

PCAF       green

IV.  Penticton 10.7 cm Flux

Observed           03 Aug 168

Predicted   04 Aug-06 Aug  160/160/160

90 Day Mean        03 Aug 167

V.  Geomagnetic A Indices

Observed Afr/Ap 02 Aug  028/037

Estimated Afr/Ap 03 Aug  018/020

Predicted Afr/Ap 04 Aug-06 Aug  012/012-010/010-010/010

VI.  Geomagnetic Activity Probabilities 04 Aug-06 Aug

A.  Middle Latitudes

Active                30/25/25

Minor storm           15/10/10

Major-severe storm    05/05/05

B.  High Latitudes

Active                35/30/30

Minor storm           20/15/15

Major-severe storm    05/05/05