:Product: 20000410RSGA.txt
:Issued: 2000 Apr 10 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 101 ISSUED AT 2200Z ON 10 APR 2000
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  09/2100Z
TO 10/2100Z:  SOLAR ACTIVITY HAS BEEN MODERATE. REGION 8948 (S15W19)
PRODUCED AN M3/2B FLARE AT 2342Z ACCOMPANIED BY A TYPE II SWEEP.
THERE WAS NO EVIDENCE IN THE LASCO CORONAGRAPH DATA FOR A CME
ASSOCIATED WITH THIS EVENT. THIS REGION CONTINUES TO BE THE DOMINANT
PRODUCER OF SOLAR ACTIVITY ON THE DISK AND CONTINUES TO SHOW A DELTA
SPOT. THE SIZE AND NUMBER OF SPOTS FOR 8948 REMAINED FAIRLY STEADY
DURING THE PERIOD. SEVERAL NEW REGIONS WERE ASSIGNED TODAY: 8954
(N32E65), 8955 (S22E75), 8956 (N11E53), AND 8957 (S09W24). ALL OF
THESE REGIONS WERE SIMPLE AND STABLE. REGION 8957 EMERGED JUST
NORTHWEST OF 8948 WITH ITS OWN IDENTITY AS A SIMPLE BIPOLAR GROUP.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. THERE CONTINUES TO BE A FAIR-TO-GOOD CHANCE FOR
ADDITIONAL, ISOLATED M-CLASS EVENTS FROM REGION 8948.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 09/2100Z TO 10/2100Z:
THE GEOMAGNETIC FIELD WAS UNSETTLED TO ACTIVE DURING THE PAST 24
HOURS. SLIGHTLY ENHANCED SOLAR WIND SPEEDS (450-550 KM/S) WERE
ACCOMPANIED BY A PERSISTENT BUT WEAK NEGATIVE INTERPLANETARY BZ (-3
TO -5 NT), AND PRODUCED AN EXTENDED INTERVAL OF ACTIVE LEVELS FROM
09/2100-10/1200Z. CONDITIONS DECREASED TO QUIET TO UNSETTLED LEVELS
FROM 1200Z THROUGH THE END OF THE DAY. THE GREATER THAN 2 MEV
ELECTRON FLUXES ATTAINED HIGH LEVELS AT 1355Z.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE MOSTLY UNSETTLED FOR THE NEXT THREE DAYS. THERE IS A
SLIGHT CHANCE FOR SOME HIGH-LATITUDE ACTIVE PERIODS ON THE SECOND
DAY.
III.  EVENT PROBABILITIES 11 APR-13 APR
CLASS M    50/50/50
CLASS X    05/05/05
PROTON     05/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           10 APR 178
PREDICTED   11 APR-13 APR  175/175/180
90 DAY MEAN        10 APR 186
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 09 APR  012/013
ESTIMATED AFR/AP 10 APR  018/018
PREDICTED AFR/AP 11 APR-13 APR  010/010-012/015-010/012
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 11 APR-13 APR
A.  MIDDLE LATITUDES
ACTIVE                20/20/20
MINOR STORM           10/10/10
MAJOR-SEVERE STORM    05/05/05
B.  HIGH LATITUDES
ACTIVE                25/25/25
MINOR STORM           10/10/10
MAJOR-SEVERE STORM    05/05/05