:Product: Report of Solar-Geophysical Activity
:Issued: 2000 Mar 31 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 091 ISSUED AT 2200Z ON 31 MAR 2000
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  30/2100Z
TO 31/2100Z:  SOLAR ACTIVITY BECAME HIGH DUE TO THE LARGE NUMBER OF
M-CLASS EVENTS THAT OCCURRED. MULTIPLE REGIONS WERE RESPONSIBLE FOR
THIS INCREASE IN ACTIVITY.  REGION 8939 (N22E56) PRODUCED THE
LARGEST EVENT - AN M4/SF AT 31/1019Z. THIS FLARE ALSO PRODUCED A
WEAK TYPE IV AND MINOR CENTIMETER BURSTS. REGION 8939 ALSO PRODUCED
M1/SF FLARES AT 31/0755Z, 31/1318Z, AND 31/1655Z. THIS REGION'S
SMALL SIZE BELIES ITS M-CLASS FLARE PRODUCTION.  REGION 8936
(S14E56) GREW AT A MODERATE PACE DURING THE PERIOD AND EXHIBITED
INCREASING MAGNETIC GRADIENTS AND A POSSIBLE DELTA CONFIGURATION.
THIS REGION PRODUCED AN M2/2B AT 30/2324Z AND AN M1/SN AT 31/0652Z
(WITH A LARGE CORONAL MASS EJECTION). REGION 8925 (S18W32) PRODUCED
AN M2/1N AT 31/1901Z. THIS REGION WAS PREDOMINANTLY STABLE AND
EXHIBITED SOME MAGNETIC COMPLEXITY. SEVERAL FILAMENTS IN THE NORTH
CENTRAL PORTION OF THE SUN FADED DURING THE PERIOD.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY SHOULD REMAIN AT A
MODERATE LEVEL FOR THE NEXT SEVERAL DAYS. CONTINUED GROWTH IN REGION
8936 WOULD INCREASE THE FREQUENCY OF M-CLASS EVENTS FROM THAT
REGION. REGION 8939 COULD CONTINUE TO PRODUCE M-CLASS EVENTS BUT DUE
TO ITS SMALL AREA IN WHITE LIGHT, IT IS LIKELY THIS REGION WILL
QUIET DURING THE PERIOD.  THERE IS A SLIGHT POSSIBILITY OF A MAJOR
FLARE DURING THE NEXT THREE DAYS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 30/2100Z TO 31/2100Z:
THE GEOMAGNETIC FIELD WAS PREDOMINANTLY UNSETTLED TO ACTIVE. ISOLATED
MINOR STORMING WAS ALSO OBSERVED. THE SOURCE OF THIS DISTURBANCE IS
UNKNOWN. SOLAR WIND PARAMETERS WERE REASONABLY BENIGN EXCEPT FOR
SOME PERIODS OF NEGATIVE BZ AND THE PASSAGE OF A SECTOR BOUNDARY
DURING THE PERIOD.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD SHOULD
BECOME QUIET TO UNSETTLED FOR THE NEXT THREE DAYS. ISOLATED ACTIVE
CONDITIONS COULD BE EXPERIENCED EARLY ON 01 APR AND AGAIN ON 03 APR.
THERE IS A POSSIBILITY OF A SOLAR PROTON EVENT DURING THE NEXT THREE
DAYS.
III.  EVENT PROBABILITIES 01 APR-03 APR
CLASS M    85/85/85
CLASS X    20/20/20
PROTON     05/05/10
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           31 MAR 225
PREDICTED   01 APR-03 APR  225/225/223
90 DAY MEAN        31 MAR 181
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 30 MAR  008/010
ESTIMATED AFR/AP 31 MAR  015/020
PREDICTED AFR/AP 01 APR-03 APR  010/012-008/010-010/015
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 01 APR-03 APR
A.  MIDDLE LATITUDES
ACTIVE                25/15/25
MINOR STORM           15/05/15
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                30/15/30
MINOR STORM           15/05/15
MAJOR-SEVERE STORM    01/01/01