Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 19 Sep 2002

By SpaceRef Editor
September 19, 2002
Filed under , ,
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 262 Issued at 2200Z on 19 Sep 2002

IA.  Analysis of Solar Active Regions and Activity from  18/2100Z
to 19/2100Z:  Solar activity was low. The largest event of the period
was a C4/1f flare from Region 125 (S08E55). An associated Type II
radio sweep and CME was observed with this flare, but the ejecta was
not earthward directed.  Region 119 (S14W10) produced occasional low
C-class flares. This region continues to develop and a weak delta
configuration is now evident.  Region 105 (S08W83) also produced
minor C-class flares as it rotates around the west limb. New Region
126 (S23E75) was numbered today.

IB.  Solar Activity Forecast:  Solar activity is expected to be low
to moderate. Developing Region 119 has best potential for a low
M-class flare. There is still a small chance for a low M-class flare
from Region 105 on the west limb.

IIA.  Geophysical Activity Summary 18/2100Z to 19/2100Z:
The geomagnetic field ranged from quiet to minor storm levels. A weak
shock was observed at the ACE spacecraft just before 19/0600Z. Solar
wind speed gradually increased to over 750 km/s by late in the
period, but total magnetic field measurements and densities remained
very low. This disturbance is likely associated with the C8 flare
and CME observed on 17 September. The greater than 2 MeV electron
flux was at moderate to high levels.

IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to continue at unsettled to minor storm levels through day
one. Unsettled conditions are expected to prevail after the current
disturbance subsides.

III.  Event Probabilities 20 Sep-22 Sep
Class M    40/40/40
Class X    05/05/05
Proton     05/05/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           19 Sep 165
Predicted   20 Sep-22 Sep  165/160/155
90 Day Mean        19 Sep 178

V.  Geomagnetic A Indices
Observed Afr/Ap 18 Sep  013/014
Estimated Afr/Ap 19 Sep  018/018
Predicted Afr/Ap 20 Sep-22 Sep  020/020-008/010-008/010

VI.  Geomagnetic Activity Probabilities 20 Sep-22 Sep
A.  Middle Latitudes
Active                50/30/20
Minor storm           30/10/05
Major-severe storm    15/05/01
B.  High Latitudes
Active                40/40/25
Minor storm           40/15/05
Major-severe storm    20/10/01

SpaceRef staff editor.