NOAA SEC Report of Solar-Geophysical Activity 12 Apr 2002

:Product: Report of Solar-Geophysical Activity

:Issued: 2002 Apr 12 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 102 Issued at 2200Z on 12 Apr 2002

IA.  Analysis of Solar Active Regions and Activity from  11/2100Z

to 12/2100Z:  Solar activity was at moderate levels.  Region 9901

(N21W26) produced an M4/1F flare on 12/1802 UTC with an associated

Type IV Radio Sweep.  Region 9893 (N20W39) has developed a delta

magnetic configuration in the trailing spot and has increased in

area and spot count.  LASCO/EIT imagery indicates that Region 9893

is the most likely source of an optically uncorrelated M1.4 flare

that occurred on 12/1310 UTC.  Region 9906 (S16E26) has shown rapid

growth in spot count, area, and now has a beta-gamma magnetic

configuration.  This region also shows some indication of a

developing delta magnetic  configuration.  As Region 9907 (S05E61)

rotates onto the disk it has revealed a moderate size spot group and

a beta-gamma magnetic classification.  One new region was numbered

today:  Region 9908 (N05W25).

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

moderate.  Region 9893/9901 complex has been active and has two

delta configurations.  The potential for M-class events is good.

Region 9906 and 9907 are developing and have a slight chance of

M-class events.

IIA.  Geophysical Activity Summary 11/2100Z to 12/2100Z:

The geomagnetic field was at quiet to unsettled levels with one 3

hour period of minor storm conditions.  This isolated minor storm

condition coincided with a sector boundary crossing.  At the time of

this issue the NASA/ACE EPAM data have shown a steady increase in

low energy protons possibly due to expected CME shock.

IIB.  Geophysical Activity Forecast:  The geomagnetic field is

expected to be quiet to active.  A CME shock is expected midday on

day one of the forecast period.  A second shock expected midday on

day two of the forecast period.

III.  Event Probabilities 13 Apr-15 Apr

Class M    65/65/60

Class X    10/10/10

Proton     10/10/05

PCAF       yellow

IV.  Penticton 10.7 cm Flux

Observed           12 Apr 212

Predicted   13 Apr-15 Apr  210/210/205

90 Day Mean        12 Apr 202

V.  Geomagnetic A Indices

Observed Afr/Ap 11 Apr  010/013

Estimated Afr/Ap 12 Apr  014/015

Predicted Afr/Ap 13 Apr-15 Apr  015/015-015/020-010/015

VI.  Geomagnetic Activity Probabilities 13 Apr-15 Apr

A.  Middle Latitudes

Active                25/30/30

Minor storm           10/15/15

Major-severe storm    05/05/05

B.  High Latitudes

Active                25/30/30

Minor storm           10/15/15

Major-severe storm    05/05/05