:Product: 20000718RSGA.txt
:Issued: 2000 Jul 18 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 200 ISSUED AT 2200Z ON 18 JUL 2000
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  17/2100Z
TO 18/2100Z:  SOLAR ACTIVITY REMAINED AT A MODERATE LEVEL.  DECAYING
REGION 9077 (N18W57) PRODUCED AN M1/2B FLARE AT 18/0515Z WITH WEAK
TYPE II AND IV BURSTS.  REGION 9087 (S12E12) GENERATED AN M3/2N
FLARE AT 18/1419Z.  THIS REGION ALSO GENERATED A LONG DURATION M3/2N
AT 18/1945Z.  IN THE LAST 24 HOURS, THIS REGION EXHIBITED
SIGNIFICANT GROWTH JUST AHEAD OF THE PREEXISTING LEADER SPOTS.  IT
IS LIKELY THAT A DELTA CONFIGURATION FORMED ALSO INDICATING THE
PRESENCE OF STRONG MAGNETIC GRADIENTS.  SEVERAL NEW REGIONS WERE
NUMBERED.  THE MOST SIGNIFICANT WAS REGION 9097 (N06E76) THAT
ROTATED ONTO THE DISK WITH BRIGHT COMPACT PLAGE, A MODERATE SIZE D
CLASS SUNSPOT GROUP, AND FREQUENT SUBFLARES.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY SHOULD BE MODERATE TO
HIGH.  A POSSIBILITY REMAINS OF A DECAY PHASE MAJOR FLARE FROM
REGION 9077.  HOWEVER, REGION 9087 SHOULD BEGIN TO PRODUCE MORE
FREQUENT M-CLASS EVENTS DUE TO NEARBY FLUX EMERGENCE.  IF THE AREA
OF NEW FLUX BEGINS TO MERGE WITH THE PREEXISTING FIELDS, MAJOR
FLARES WILL BECOME LIKELY.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 17/2100Z TO 18/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO SLIGHTLY UNSETTLED.  SOLAR WIND
VELOCITY REMAINED ELEVATED, AT TIMES EXCEEDING 600 KM/S.  THE
GREATER THAN 10 MEV FLUX BEGAN THE PERIOD AT APPROXIMATELY 50 PFU
AND DECLINED SLOWLY TO NEAR 20 PFU AT THE END OF THE PERIOD.  AN
INTERMITTENT FORBUSH DECREASE WAS IN PROGRESS DURING THE DAY.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD SHOULD BE
PREDOMINANTLY QUIET TO UNSETTLED FOR THE NEXT THREE DAYS.
OCCASIONAL ACTIVE PERIODS ARE POSSIBLE DURING THAT TIME.  BASED UPON
THE CURRENT DECAY RATE OF THE GREATER THAN 10 MEV PROTON FLUX, THIS
EVENT SHOULD DECREASE BELOW THRESHOLD LATE ON 19 JUL.
III.  EVENT PROBABILITIES 19 JUL-21 JUL
CLASS M    90/90/90
CLASS X    40/40/40
PROTON     99/50/40
PCAF       YELLOW
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           18 JUL 249 (ESTIMATED)
PREDICTED   19 JUL-21 JUL  255/260/255
90 DAY MEAN        18 JUL 187
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 17 JUL  008/009
ESTIMATED AFR/AP 18 JUL  008/008
PREDICTED AFR/AP 19 JUL-21 JUL  010/010-012/012-012/012
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 19 JUL-21 JUL
A.  MIDDLE LATITUDES
ACTIVE                20/25/25
MINOR STORM           10/10/10
MAJOR-SEVERE STORM    05/05/05
B.  HIGH LATITUDES
ACTIVE                20/30/30
MINOR STORM           10/15/15
MAJOR-SEVERE STORM    05/05/05