:Product: Report of Solar-Geophysical Activity
:Issued: 2000 Feb 27 2210 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 058 ISSUED AT 2200Z ON 27 FEB 2000
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  26/2100Z
TO 27/2100Z:  SOLAR ACTIVITY BECAME MODERATE. REGION 8889 (N20E35)
PRODUCED A LONG DURATION M1/2F FLARE FROM 26/2333-27/0103Z. THIS
EVENT WAS PRECEDED BY A NEARBY FILAMENT ERUPTION AND ERUPTIVE
PROMINENCE AT NE44 TO 0.29 RADIUS ABOVE THE LIMB. MINOR RADIO BURSTS
ACCOMPANIED THIS EVENT. THE SOHO CORONAGRAPH RECORDED A VERY LARGE
AND DENSE CORONAL MASS EJECTION FOLLOWING THE ERUPTION AND FLARE. IT
WAS SEEN TO PROPAGATE NORTHWARD OUT OF THE ECLIPTIC. REGION 8882
(S16W04) PRODUCED FREQUENT C-CLASS SUBFLARES. SOME GROWTH WAS NOTED
HERE BUT MAGNETIC COMPLEXITY MAY BE DECREASING. REGION 8891 (S17E49)
ALSO PRODUCED SEVERAL SUBFLARES BUT WAS GENERALLY STABLE IN OTHER
PARAMETERS.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY SHOULD BE LOW TO
MODERATE. M-CLASS EVENTS ARE POSSIBLE FROM REGIONS 8882 AND 8891.
THERE IS A SMALL POSSIBILITY THAT EITHER OF THESE REGIONS COULD
PRODUCE A MAJOR FLARE. SHOULD THE FILAMENT NEAR REGION 8889 REFORM,
ANOTHER ERUPTION COULD BE POSSIBLE.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 26/2100Z TO 27/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. SOLAR WIND VELOCITY
REMAINED ELEVATED AT APPROXIMATELY 550-600 KM/S. ENERGETIC ELECTRON
FLUXES AT GEOSYNCHRONOUS ORBIT REMAINED AT HIGH LEVELS DURING THE
PERIOD.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD SHOULD
REMAIN QUIET TO UNSETTLED FOR THE NEXT THREE DAYS. ISOLATED ACTIVE
PERIODS REMAIN POSSIBLE UNTIL SOLAR WIND VELOCITY DECREASES TO
BACKGROUND LEVEL. ENERGETIC ELECTRON FLUXES SHOULD REMAIN ELEVATED
FOR MOST IF NOT ALL OF THE FORECAST PERIOD.
III.  EVENT PROBABILITIES 28 FEB-01 MAR
CLASS M    70/70/70
CLASS X    20/20/20
PROTON     10/10/10
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           27 FEB 227
PREDICTED   28 FEB-01 MAR  229/231/233
90 DAY MEAN        27 FEB 166
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 26 FEB  010/012
ESTIMATED AFR/AP 27 FEB  009/008
PREDICTED AFR/AP 28 FEB-01 MAR  008/010-008/008-005/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 28 FEB-01 MAR
A.  MIDDLE LATITUDES
ACTIVE                25/15/10
MINOR STORM           10/05/05
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                25/15/10
MINOR STORM           10/15/05
MAJOR-SEVERE STORM    01/01/01