NOAA SEC Report of Solar-Geophysical Activity 6 Apr 2002

:Product: Report of Solar-Geophysical Activity

:Issued: 2002 Apr 06 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 096 Issued at 2200Z on 06 Apr 2002

IA.  Analysis of Solar Active Regions and Activity from  05/2100Z

to 06/2100Z:  Solar activity was at low levels.  Region 9893 (N19E40)

produced the largest flare during the period, a C9/1F flare

occurring at 06/0619 UTC.  This region has become slightly more

complex during the period and has also seen an increase in penumbral

coverage.  Many minor C-class flares from the more ominous regions

were seen on the disk today as well.  One worthy of mention, a C2/Sf

flare that materialized from an area void of spots (S17E48) also

produced a weak Type II sweep with an estimated shock velocity of

296 km/s.  LASCO imagery doesn’t depict any geoeffective potential

to this event. New Regions 9897 (S01W02), 9898 (S19E66), and 9899

(N18E72) were numbered today.

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

low to moderate levels.  A chance for an isolated major flare exists

due to the magnetic complexity seen in several regions.

IIA.  Geophysical Activity Summary 05/2100Z to 06/2100Z:

The geomagnetic field activity was at quiet levels.

IIB.  Geophysical Activity Forecast:  Geomagnetic field activity is

expected to be quiet on day one of the forecast.  A slight chance of

isolated active conditions exist for days two and three.  The

greater than 2 MeV electron flux dropped below event levels at

05/2140 UTC (max flux 2140 pfu’s at 05/1725 UTC) , although levels

remain elevated at the time of this writing.

III.  Event Probabilities 07 Apr-09 Apr

Class M    60/60/60

Class X    10/10/10

Proton     05/05/05

PCAF       green

IV.  Penticton 10.7 cm Flux

Observed           06 Apr 206

Predicted   07 Apr-09 Apr  205/200/190

90 Day Mean        06 Apr 203

V.  Geomagnetic A Indices

Observed Afr/Ap 05 Apr  003/006

Estimated Afr/Ap 06 Apr  004/006

Predicted Afr/Ap 07 Apr-09 Apr  010/010-012/012-008/010

VI.  Geomagnetic Activity Probabilities 07 Apr-09 Apr

A.  Middle Latitudes

Active                15/20/20

Minor storm           01/05/05

Major-severe storm    01/01/01

B.  High Latitudes

Active                15/25/25

Minor storm           01/10/10

Major-severe storm    01/01/01