:Product: 19981018RSGA.txt
:Issued: 1998 Oct 18 2200 UTC
# 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 291 ISSUED AT 2200Z ON 18 OCT 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  17/2100Z
TO 18/2100Z:  SOLAR ACTIVITY BECAME MODERATE WHEN REGION 8358
(N15W69) PRODUCED A M2/1N FLARE AT 18/0145Z. THIS REGION BECAME VERY
ACTIVE DURING A GROWTH PERIOD THAT BEGAN WITH A C9/1F AT 17/1851Z
AND ENDED AT 18/0538Z, PRODUCING ONE M-CLASS AND FIVE C-CLASS
FLARES. ACTIVITY FROM THIS, AND ALL OTHER REGIONS HAVE BEEN VERY LOW
SINCE. NEW REGIONS 8365 (S28E10) AND 8366 (S16E35) WERE NUMBERED
TODAY BRINGING THE TOTAL TO NINE SPOT GROUPS VISIBLE IN WHITE LIGHT.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW.
REGION 8358 WILL LIKELY PRODUCE FURTHER C-CLASS ACTIVITY AND STILL
HAS POTENTIAL FOR AN ISOLATED M-CLASS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 17/2100Z TO 18/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED TO ACTIVE WITH ISOLATED PERIODS OF MINOR
STORMING IN RESPONSE TO THE CME ON 15 OCT.
III.  EVENT PROBABILITIES 19 OCT-21 OCT
CLASS M    25/15/15
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           18 OCT 126
PREDICTED   19 OCT-21 OCT  130/130/135
90 DAY MEAN        18 OCT 132
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 17 OCT  009/009
ESTIMATED AFR/AP 18 OCT  012/015
PREDICTED AFR/AP 19 OCT-21 OCT  025/030-015/020-010/015
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 19 OCT-21 OCT
A.  MIDDLE LATITUDES
ACTIVE                50/25/10
MINOR STORM           30/15/01
MAJOR-SEVERE STORM    10/01/01
B.  HIGH LATITUDES
ACTIVE                50/30/20
MINOR STORM           40/20/10
MAJOR-SEVERE STORM    10/05/01