:Product: 19981127RSGA.txt
:Issued: 1998 Nov 27 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 331 ISSUED AT 2200Z ON 27 NOV 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  26/2100Z
TO 27/2100Z:  SOLAR ACTIVITY BECAME MODERATE. REGION 8392 (S23W05)
PRODUCED A M1/2N AT 27/0743Z. THIS EVENT HAD MODERATE CENTIMETRIC
BURSTS INCLUDING 390 SFU'S AT 2695 MHZ. A TYPE II SWEEP WITH 700
KM/S SHOCK SPEED WAS ALSO OBSERVED WITH THIS EVENT. THE NORTHERN
HALF OF A 15 DEGREE LONG FILAMENT SHOWED STRONG LINEAR CHANGE
SHORTLY BEFORE THE FLARE BEGAN AND ERUPTED AS THE FLARE OCCURRED.
REGIONS 8395 (N19E44) EXHIBITED LITTLE CHANGE IN THE PAST 24 HOURS
AND CONTINUES TO PRODUCE OCCASIONAL MINOR C-CLASS SUBFLARES. REGION
8393 (S19E24) MAINTAINS A BETA-GAMMA CONFIGURATION IN A
MODERATE-SIZED F-TYPE SPOT GROUP.  IT DEVELOPED FURTHER MAGNETIC
COMPLEXITY ALONG THE EASTERN PORTION OF THE REGION AND THE SOUTHERN
EDGE OF THE LEADER SPOTS WHERE FREQUENT FLUCTUATIONS AND SURGES WERE
NOTED. REMAINDER OF THE DISK AND LIMB WAS QUIET.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO REMAIN
LOW TO MODERATE. REGION 8395 WILL CONTINUE TO BE THE PRIMARY FLARE
PRODUCER WITH THE BEST CHANCE OF ISOLATED LOW M-CLASS ACTIVITY.
REGION 8393'S RECENT GROWTH BEARS WATCHING - MOSTLY C-CLASS FLARES
EXPECTED WITH A SMALL CHANCE FOR A LOW M-CLASS. REGION 8392 WAS IN
DECAY WHEN THE M1/2N FLARE OCCURRED. THE REGION CONTINUES TO DECAY
SLOWLY - FURTHER M-CLASS ACTIVITY IS UNLIKELY.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 26/2100Z TO 27/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD SHOULD
REMAIN QUIET TO UNSETTLED FOR DAY 1 AND 2. ACTIVE CONDITIONS MAY
DEVELOP ON DAY 3 IN RESPONSE TO THE M1/2N FLARE OBSERVED TODAY.
III.  EVENT PROBABILITIES 28 NOV-30 NOV
CLASS M    40/40/40
CLASS X    05/05/05
PROTON     05/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           27 NOV 159
PREDICTED   28 NOV-30 NOV  160/160/160
90 DAY MEAN        27 NOV 132
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 26 NOV  010/011
ESTIMATED AFR/AP 27 NOV  010/009
PREDICTED AFR/AP 28 NOV-30 NOV  010/010-010/012-015/025
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 28 NOV-30 NOV
A.  MIDDLE LATITUDES
ACTIVE                20/20/30
MINOR STORM           01/01/05
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                20/20/35
MINOR STORM           01/01/10
MAJOR-SEVERE STORM    01/01/01