:Product: 19980331RSGA.txt
:Issued: 1998 Mar 31 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 090 ISSUED AT 2200Z ON 31 MAR 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  30/2100Z
TO 31/2100Z:  SOLAR ACTIVITY WAS LOW. SEVERAL C-CLASS EVENTS OCCURRED
TODAY, THE LARGEST OF WHICH WAS A C2/SF AT 0302Z FROM REGION 8190
(S22E36). REGION 8190 HAS SHOWN STEADY GROWTH DURING THE PAST 24
HOURS AND WAS THE SOURCE OF THE MAJORITY OF TODAY'S FLARE ACTIVITY.
NEW REGION 8191 (S23E48) WAS ASSIGNED TODAY AND IS A SMALL BIPOLAR
GROUP JUST EAST OF 8190. REGION 8185 (S25W51) IS STILL THE LARGEST
REGION ON THE DISK BUT WAS DECLINING IN SUNSPOT AREA AND MAGNETIC
FIELD INTENSITY. LASCO IMAGES BEGINNING AT 31/0626Z SHOWED A LARGE
ERUPTION OF MATERIAL; THE PROJECTION WAS FROM THE SOUTHWESTERN PART
OF THE DISK. THE LACK OF ANY CORRESPONDING SIGNATURES ON THE DISK
SUGGEST THAT THE SOURCE WAS PROBABLY ON THE BACK SIDE OF THE SUN.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW.
THERE CONTINUES TO BE A SLIGHT CHANCE FOR ISOLATED M-CLASS EVENTS.
REGION 8190 IS EXPECTED TO BE THE MOST ACTIVE REGION OVER THE NEXT
THREE DAYS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 30/2100Z TO 31/2100Z:
THE GEOMAGNETIC FIELD WAS MOSTLY QUIET TO UNSETTLED. MINOR INTENSITY
SUBSTORMS WERE RECORDED AT HIGH LATITUDE BETWEEN FROM 0300-0900Z,
LEADING TO UNSETTLED LEVELS AT MID-LATITUDE STATIONS  AND ACTIVE
LEVELS FOR THE PLANETARY INDICES. THE FIELD WAS QUIET AT ALL
LATITUDES FOR THE REMAINDER OF THE PERIOD. THE GREATER THAN 2 MEV
ELECTRON FLUXES ATTAINED HIGH LEVELS.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED TO ACTIVE, WITH A CHANCE FOR SOME MINOR
STORM LEVEL CONDITIONS, OVER THE NEXT 24-48 HOURS. ENHANCED ACTIVITY
IS POSSIBLE BECAUSE OF A TRANSIENT ASSOCIATED WITH THE FILAMENT
ERUPTION ON 30 MARCH. CONDITIONS ARE EXPECTED TO RETURN TO UNSETTLED
TO QUIET LEVELS BY THE THIRD DAY.
III.  EVENT PROBABILITIES 01 APR-03 APR
CLASS M    15/15/15
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           31 MAR 108
PREDICTED   01 APR-03 APR  110/110/105
90 DAY MEAN        31 MAR 099
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 30 MAR  006/010
ESTIMATED AFR/AP 31 MAR  012/012
PREDICTED AFR/AP 01 APR-03 APR  020/015-012/020-007/015
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 01 APR-03 APR
A.  MIDDLE LATITUDES
ACTIVE                50/40/25
MINOR STORM           20/20/15
MAJOR-SEVERE STORM    05/05/05
B.  HIGH LATITUDES
ACTIVE                60/50/25
MINOR STORM           30/25/20
MAJOR-SEVERE STORM    05/05/05