NOAA SEC Product: Report of Solar-Geophysical Activity 17 Feb 2002

:Product: Report of Solar-Geophysical Activity

:Issued: 2002 Feb 17 2210 UT

# 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 048 Issued at 2200Z on 17 Feb 2002

IA.  Analysis of Solar Active Regions and Activity from  16/2100Z

to 17/2100Z:  Solar activity remained at low levels. Region 9830

(S18E31) was the most active of the visible regions. It produced

occasional subflares as it grew at a gradual pace with increased

sunspot area and magnetic complexity. A magnetic delta configuration

may have developed within its leader spots. Region 9825 (N12W35)

continued to gradually decay and simplify. The remaining active

regions were unremarkable.

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

low to moderate levels. There is a chance for an isolated M-class

flare from Region 9830.

IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z:

Geomagnetic field activity was at quiet to active levels. Activity

increased to unsettled to active levels during 17/0300 – 0900 UTC

following a sudden impulse at 17/0257 UTC (13 nT, as measured by the

Boulder USGS magnetometer). Field activity decreased to quiet to

unsettled levels after 17/0900 UTC. This brief increase in activity

appeared to be the result of a weak CME passage.

IIB.  Geophysical Activity Forecast:  Geomagnetic field activity is

expected to be at quiet to unsettled levels.

III.  Event Probabilities 18 Feb-20 Feb

Class M    40/40/40

Class X    05/05/05

Proton     05/05/05

PCAF       green

IV.  Penticton 10.7 cm Flux

Observed           17 Feb 197

Predicted   18 Feb-20 Feb  195/195/190

90 Day Mean        17 Feb 222

V.  Geomagnetic A Indices

Observed Afr/Ap 16 Feb  002/005

Estimated Afr/Ap 17 Feb  008/008

Predicted Afr/Ap 18 Feb-20 Feb  010/010-010/012-010/012

VI.  Geomagnetic Activity Probabilities 18 Feb-20 Feb

A.  Middle Latitudes

Active                25/20/20

Minor storm           10/10/10

Major-severe storm    01/01/01

B.  High Latitudes

Active                30/25/25

Minor storm           15/15/15

Major-severe storm    05/05/05