NOAA SEC Report of Solar-Geophysical Activity 4 Sep 2001

:Product: Report of Solar-Geophysical Activity
:Issued: 2001 Sep 04 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 247 Issued at 2200Z on 04 Sep 2001
IA.  Analysis of Solar Active Regions and Activity from  03/2100Z
to 04/2100Z:  Solar activity was moderate. A gradual rise in X-rays
began at around 04/1000Z and continued through the end of this
period. Since 04/1500Z, the X-ray baseline ranged from C4 - C8 with
occasional fluctuations to the M1 level. Development within regions
near the SE limb, the SW limb and within Region 9601 (N13W22) are
the likely sources of the enhanced X-rays. Region 9606 (S17E45)
produced an impulsive M1/1n at 04/2017Z. Region 9601, at almost 800
millionths of white light area is moderately complex and the largest
region on the visible disk. Several plage fluctuations were observed
in this region, but only minor C-class flareS were observed. The two
M-class flares observed yesterday at 03/1545Z and 03/1841Z were
likely associated with CMEs off the SE limb. New region 9607
(S16E68) was numbered today.
IB.  Solar Activity Forecast:  Solar activity is expected to be at
moderate to high levels. New regions near the SE limb and developing
regions near the SW limb have potential for isolated M-class flares.
Region 9601 also has potential for M-class flares.
IIA.  Geophysical Activity Summary 03/2100Z to 04/2100Z:
The geomagnetic field was mostly at unsettled to active levels. A
high speed coronal hole stream and possibly some weak CME effects
are producing the disturbed conditions.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to return to quiet to unsettled conditions by the end of
day one and persist through days two and three.
III.  Event Probabilities 05 Sep-07 Sep
Class M    70/70/70
Class X    15/15/15
Proton     15/15/15
PCAF       yellow
IV.  Penticton 10.7 cm Flux
Observed           04 Sep 218
Predicted   05 Sep-07 Sep  210/210/205
90 Day Mean        04 Sep 158
V.  Geomagnetic A Indices
Observed Afr/Ap 03 Sep  012/017
Estimated Afr/Ap 04 Sep  015/018
Predicted Afr/Ap 05 Sep-07 Sep  010/012-010/010-010/010
VI.  Geomagnetic Activity Probabilities 05 Sep-07 Sep
A.  Middle Latitudes
Active                30/20/20
Minor storm           10/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                40/25/25
Minor storm           15/05/05
Major-severe storm    05/01/01