Joint USAF/NOAA Report of Solar and Geophysical Activity 11 Sep 2002

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 254 Issued at 2200Z on 11 Sep 2002

IA.  Analysis of Solar Active Regions and Activity from  10/2100Z
to 11/2100Z:  Solar activity has been moderate.  Region 105 (S09E28)
produced the largest event of the period, an M2/2b flare at 11/0735
UTC with an associated tenflare (230 sfu).  Region 107 (N11E30) was
a source of several C-class flares during the period, and Region 100
(S19W64) also produced a C-class flare.  Region 103 (N14W33) has
remained quiescent, but appears somewhat more compact today and
retains moderate magnetic complexity.

IB.  Solar Activity Forecast:  Solar activity is expected to be at
moderate levels for the next three days.  Region 105 is a likely
source of further M-class activity.  Regions 103 and 107 may become
more active during the period and could produce M-class flares as
well.

IIA.  Geophysical Activity Summary 10/2100Z to 11/2100Z:
Geomagnetic field conditions have ranged from quiet to major storm
levels.  Onset of coronal hole high speed stream effects have been
evident since about 11/0900 UTC, and the single period of major
storm conditions observed at higher latitudes occurred shortly
thereafter.  The remainder of the day had conditions in the
unsettled to minor storm range.

IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be mainly unsettled to active for the next 24-48 hours. 
Isolated minor storm conditions may also occur, especially at higher
latitudes.  Conditions are expected to be in the quiet to unsettled
range by the end of the forecast period.

III.  Event Probabilities 12 Sep-14 Sep
Class M    65/65/65
Class X    10/10/10
Proton     05/05/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           11 Sep 216
Predicted   12 Sep-14 Sep  220/220/225
90 Day Mean        11 Sep 173

V.  Geomagnetic A Indices
Observed Afr/Ap 10 Sep  014/024
Estimated Afr/Ap 11 Sep  020/025
Predicted Afr/Ap 12 Sep-14 Sep  018/018-015/018-012/015

VI.  Geomagnetic Activity Probabilities 12 Sep-14 Sep
A.  Middle Latitudes
Active                35/30/25
Minor storm           10/10/05
Major-severe storm    05/01/01
B.  High Latitudes
Active                35/35/30
Minor storm           15/15/10
Major-severe storm    05/05/01