Status Report

NOAA/USAF Report of Solar-Geophysical Activity 11 November 2000

By SpaceRef Editor
November 11, 2000
Filed under
:Product: Report of Solar-Geophysical Activity
:Issued: 2000 Nov 11 2200 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 316 Issued at 2200Z on 11 Nov 2000
IA.  Analysis of Solar Active Regions and Activity from  10/2100Z
to 11/2100Z:  Solar activity was low. There were two C-class flares
produced during the past 24 hours. The first was a C2/Sf at 0012Z
from Region 9218 (N21W90+), and the second was a C2 which was not
reported optically. An examination of SOHO/EIT images during the
second event strongly suggest that it also originated from Region
9218. Region 9221 (S12W20) showed some magnetic flux development in
the leader part of the group and Region 9227 (S12E12)  displayed new
spot growth just behind the leader spot. All regions currently on
the disk are quiet and stable.
IB.  Solar Activity Forecast:  Solar activity is expected to be
predominantly low for the next three days, but there is a slight
chance for an isolated M-class event.
IIA.  Geophysical Activity Summary 10/2100Z to 11/2100Z:
The geomagnetic field has been quiet to unsettled during the past 24
hours. Solar wind measurements from ACE indicate the onset of a
high-speed, low density flow that is consistent with a favorably
positioned solar coronal hole. The interplanetary magnetic field,
however, has been either northwards or has been fluctuating weakly
between -3 nT and +5 nT, and the geomagnetic response so far has
been weak. The proton event at greater than 100 MeV ended at 0240Z
today (based on GOES-8 flux dropping below 1 pfu). The greater than
10 MeV protons decreased during the past 24 hours but continue to be
above the event threshold of 10 pfu, with a current value at 2100Z
of 23.6 pfu.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be unsettled to active during the next 24 hours due to
possible enhanced activity from the high speed solar wind stream. A
decline to mostly unsettled is expected for the second and third
days. The greater than 10 MeV proton event is expected to end
sometime during the next 24 hours.
III.  Event Probabilities 12 Nov-14 Nov
Class M    15/15/15
Class X    01/01/01
Proton     99/30/05
PCAF       yellow
IV.  Penticton 10.7 cm Flux
Observed           11 Nov 150
Predicted   12 Nov-14 Nov  150/145/140
90 Day Mean        11 Nov 172
V.  Geomagnetic A Indices
Observed Afr/Ap 10 Nov  029/041
Estimated Afr/Ap 11 Nov  010/015
Predicted Afr/Ap 12 Nov-14 Nov  015/020-012/015-012/015
VI.  Geomagnetic Activity Probabilities 12 Nov-14 Nov
A.  Middle Latitudes
Active                35/30/25
Minor storm           25/15/10
Major-severe storm    10/05/05
B.  High Latitudes
Active                25/25/25
Minor storm           30/20/15
Major-severe storm    20/15/10

SpaceRef staff editor.