:Product: Report of Solar-Geophysical Activity
:Issued: 2000 Mar 26 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 086 ISSUED AT 2200Z ON 26 MAR 2000
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  25/2100Z
TO 26/2100Z:  SOLAR ACTIVITY WAS MODERATE DUE TO A SINGLE M-CLASS
EVENT; AN M2/SF FROM REGION 8926 (S12W55) AT 26/1734UT. THIS EVENT
ALSO PRODUCED A 3 DEGREE LONG, DISAPPEARING SOLAR FILAMENT (DSF)
NEAR THE REGION CENTER AT S11W55. THIS REGION ALSO PRODUCED A C2/SF
AT 25/2205UT. REGION 8921 (S14W02) PRODUCED A C7/1F AT 25/2243UT.
THIS EVENT WAS ACCOMPANIED BY TYPE II AND IV RADIO SWEEPS. OTHER
ACTIVE REGIONS INCLUDED: 8916 (N08W30), 8920 (N23W07), 8924
(N10E39), AND 8925 (S18E38), ALL OF WHICH PRODUCED ISOLATED OPTICAL
SUBFLARES. REGIONS 8924 AND 8925 SHOWED AN INCREASE IN SIZE DURING
THE PERIOD AND ALSO DEVELOPED INTO MORE COMPLEX BETA-GAMMA MAGNETIC
CLASSIFICATIONS.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
MOSTLY LOW WITH THE POSSIBILITY OF ISOLATED M-CLASS EVENTS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 25/2100Z TO 26/2100Z:
THE GEOMAGNETIC FIELD WAS MOSTLY QUIET TO UNSETTLED WITH ONE ISOLATED
ACTIVE PERIOD AT 26/15-1800UT.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED ON THE FIRST DAY OF THE PERIOD AND
QUIET TO ACTIVE ON THE SECOND AND THIRD DAYS. ACTIVE CONDITIONS ARE
POSSIBLE DUE TO FAVORABLE INDICATIONS, THAT THE C7/1F EVENT
DESCRIBED ABOVE, COULD HAVE ALSO PRODUCED AN EARTH-DIRECTED CORONAL
MASS EJECTION (CME). THESE INDICATORS AND THE REGION'S CENTRAL
POSITION AT THE TIME OF THE EVENT COMBINE TO PRODUCE POSSIBLE
GEOEFFECTIVE CONDITIONS. IMAGES FROM THE SOHO/LASCO SPACECRAFT WERE
NOT AVAILABLE AT THE TIME OF THE EVENT, MAKING IT DIFFICULT TO
VERIFY THE PRESENCE OF AN EARTH-DIRECTED CME.
III.  EVENT PROBABILITIES 27 MAR-29 MAR
CLASS M    60/60/60
CLASS X    10/10/10
PROTON     05/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           26 MAR 211
PREDICTED   27 MAR-29 MAR  205/200/200
90 DAY MEAN        26 MAR 177
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 25 MAR  005/008
ESTIMATED AFR/AP 26 MAR  008/008
PREDICTED AFR/AP 27 MAR-29 MAR  008/008-020/025-020/020
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 27 MAR-29 MAR
A.  MIDDLE LATITUDES
ACTIVE                30/60/60
MINOR STORM           05/10/10
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                40/70/70
MINOR STORM           10/25/20
MAJOR-SEVERE STORM    01/01/01