NOAA SEC Report of Solar-Geophysical Activity 15 Apr 2002

:Product: Report of Solar-Geophysical Activity

:Issued: 2002 Apr 15 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 105 Issued at 2200Z on 15 Apr 2002

IA.  Analysis of Solar Active Regions and Activity from  14/2100Z

to 15/2100Z:  Solar activity was moderate. The Region complex

9893/9901 (N20W75) continues to flare as it approaches the west

limb. The largest was an M3/Sf at 15/0014 UTC. This region appears

to retain its mixed polarities and sunspot delta configuration.

Region 9906 (S15W14) also produced M-class activity, a long-duration

M1/Sf at 15/0355 UTC. An apparent Earth-directed CME is visible in

LASCO coronagraph images following this flare. Decay in Region 9906

since yesterday is most notable as fragmentation in the trailer

sunspot complex. Region 9907 (S04E21) continues to develop but has

not yet produced significant activity.

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

moderate. Additional M-class flares are possible in Regions 9906 and

the 9893/9901 complex, as is an isolated major flare.

IIA.  Geophysical Activity Summary 14/2100Z to 15/2100Z:

The geomagnetic field was quiet to unsettled.

IIB.  Geophysical Activity Forecast:  The geomagnetic field is

expected to be quiet unsettled for the first day of the forecast

period. Unsettled to active conditions are expected on days two and

three in response to the CME mentioned in Part IA.

III.  Event Probabilities 16 Apr-18 Apr

Class M    75/50/50

Class X    10/05/01

Proton     10/05/01

PCAF       yellow

IV.  Penticton 10.7 cm Flux

Observed           15 Apr 203

Predicted   16 Apr-18 Apr  200/190/185

90 Day Mean        15 Apr 202

V.  Geomagnetic A Indices

Observed Afr/Ap 14 Apr  008/013

Estimated Afr/Ap 15 Apr  005/006

Predicted Afr/Ap 16 Apr-18 Apr  008/008-018/015-018/015

VI.  Geomagnetic Activity Probabilities 16 Apr-18 Apr

A.  Middle Latitudes

Active                10/30/30

Minor storm           05/10/10

Major-severe storm    01/05/05

B.  High Latitudes

Active                15/40/40

Minor storm           05/15/15

Major-severe storm    01/05/05