:Product: 19991127RSGA.txt
:Issued: 1999 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 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  26/2100Z
TO 27/2100Z:  SOLAR ACTIVITY CONTINUED AT HIGH LEVELS. REGION 8771
(S14W78) PRODUCED AN X1/2B TENFLARE AT 27/1212Z. THIS REGION ALSO
PRODUCED TWO OTHER SIGNIFICANT EVENTS - AN M2/1N AT 27/0301Z AND AN
M1/1N AT 27/0549Z. THOUGH SOME DECAY WAS OBSERVED IN THE LAST 24
HOURS, THIS REGION RETAINS CONSIDERABLE SIZE AND MAGNETIC COMPLEXITY
AS IT APPROACHES THE WEST LIMB. REGION 8778 (S14W19) CONTINUES IN A
SLOW GROWTH PHASE AND PRODUCED A C5/1N FLARE AT 27/0452Z. A LARGE,
17 DEGREE FILAMENT ERUPTED FROM S50 NEAR CENTER DISK BETWEEN 26/1700
- 1930Z.  NEW REGION 8782 (N11E01) WAS NUMBERED TODAY. NO OTHER
SIGNIFICANT ACTIVITY WAS OBSERVED.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE AT
MODERATE TO HIGH LEVELS. REGION 8771 (S14W78) SHOULD CONTINUE
PRODUCING M-CLASS ACTIVITY AS IT ROTATES AROUND THE WEST LIMB. AN
ISOLATED MAJOR FLARE IS POSSIBLE. REGION 8778 (S14W19) WILL LIKELY
CONTINUE TO PRODUCE C-CLASS ACTIVITY AND HAS POTENTIAL FOR AN
ISOLATED M-CLASS EVENT.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 26/2100Z TO 27/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO REMAIN AT QUIET LEVELS THROUGH DAY ONE, WITH UNSETTLED
TO ACTIVE CONDITIONS LIKELY ON DAY TWO AND THREE. THERE IS POTENTIAL
FOR A MINOR DISTURBANCE ON DAYS TWO AND THREE IN RESPONSE TO
YESTERDAY'S PARTIAL HALO CORONAL MASS EJECTION OFF THE WEST LIMB. WE
MAY ALSO HAVE TO CONTEND WITH THE EFFECTS OF A HIGH SPEED CORONAL
HOLE STREAM BY DAY THREE.
III.  EVENT PROBABILITIES 28 NOV-30 NOV
CLASS M    55/40/40
CLASS X    10/05/05
PROTON     05/05/05
PCAF       YELLOW
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           27 NOV 169
PREDICTED   28 NOV-30 NOV  160/150/145
90 DAY MEAN        27 NOV 165
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 26 NOV  002/004
ESTIMATED AFR/AP 27 NOV  005/008
PREDICTED AFR/AP 28 NOV-30 NOV  007/010-015/015-015/015
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 28 NOV-30 NOV
A.  MIDDLE LATITUDES
ACTIVE                15/25/25
MINOR STORM           05/10/10
MAJOR-SEVERE STORM    01/05/05
B.  HIGH LATITUDES
ACTIVE                20/30/40
MINOR STORM           10/20/20
MAJOR-SEVERE STORM    05/10/10