NOAA SEC Report of Solar-Geophysical Activity 17 May 2001

:Product: Report of Solar-Geophysical Activity
:Issued: 2001 May 17 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 137 Issued at 2200Z on 17 May 2001
IA.  Analysis of Solar Active Regions and Activity from  16/2100Z
to 17/2100Z:  Solar activity was moderate due to a single M-class
event, an M1/1f flare from Region 9455 (S16W66) at 17/1652. Regions
9451 (S20W90+), 9454 (N14W22), and 9455 all produced C-class events
during the period. Region 9455 produced a C9/1f at the end of the
reporting period. Region 9461 (N18E49), returning Region 9433
(responsible for major flares during its previous two rotations),
continued to show little activity and is currently a 4-spot D-type
group.
IB.  Solar Activity Forecast:  Solar activity is expected to be at
low to moderate levels. Regions 9454 and 9455 could produce isolated
M-class events during the forecast period.
IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z:
The geomagnetic field ranged from quiet to unsettled levels. The
greater than 2 MeV electron flux at geosynchronous orbit reached
high levels during the period.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be at quiet to unsettled levels with a possibility of
isolated active periods at high latitudes on 18 May. The greater
than 2 MeV electron flux may reach high levels during the period.
III.  Event Probabilities 18 May-20 May
Class M    40/40/40
Class X    05/05/05
Proton     05/05/05
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           17 May 147
Predicted   18 May-20 May  150/155/160
90 Day Mean        17 May 167
V.  Geomagnetic A Indices
Observed Afr/Ap 16 May  007/012
Estimated Afr/Ap 17 May  010/012
Predicted Afr/Ap 18 May-20 May  012/020-010/012-008/010
VI.  Geomagnetic Activity Probabilities 18 May-20 May
A.  Middle Latitudes
Active                30/20/20
Minor storm           10/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                35/25/25
Minor storm           15/10/10
Major-severe storm    01/01/01