:Product: 20000720RSGA.txt
:Issued: 2000 Jul 20 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 202 ISSUED AT 2200Z ON 20 JUL 2000
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  19/2100Z
TO 20/2100Z:  SOLAR ACTIVITY REMAINED AT A HIGH LEVEL.  REGION 9087
(S11W11) PRODUCED AN IMPULSIVE M5/1B AT 20/2025Z WITH A 10 CM BURST
OF 490 SFU.  THIS REGION ALSO PRODUCED A MODERATE DURATION M3/1F AT
20/1006Z WITH MEDIUM INTENSITY CENTIMETRIC BURSTS.  THE GROWTH RATE
IN THIS REGION SLOWED.  AREAS OF MAGNETIC COMPLEXITY REMAINED BUT
THE STEEP GRADIENTS OBSERVED IN THE PREVIOUS TWO DAYS APPEAR TO HAVE
LESSENED.  REGION 9097 (N05E55) PRODUCED SEVERAL C-CLASS EVENTS.
THIS REGION SHOWED A WEAK DELTA CONFIGURATION IN ITS LEADER SPOT.
REGION 9090 (N11E21) EXHIBITED SOME LEADER GROWTH AND SEVERAL
C-CLASS EVENTS ORIGINATED FROM THAT AREA.  A TYPE II BURST OCCURRED
AT 20/1652Z WITH NO APPROPRIATE OPTICAL COUNTERPART.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY SHOULD BE MODERATE TO
HIGH FOR THE NEXT THREE DAYS.  REGION 9087 RETAINS THE CAPABILITY OF
PRODUCING OCCASIONAL M-CLASS EVENTS.  THIS REGION IS ALSO CAPABLE OF
GENERATING ISOLATED X-CLASS FLARES.  OTHER DISK REGIONS MAY
CONTRIBUTE TO FULL DISK M-CLASS FLARE PRODUCTION.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY 19/2100Z TO 20/2100Z:
THE GEOMAGNETIC FIELD BEGAN THE PERIOD AT MINOR TO MAJOR STORM
LEVELS.  FOLLOWING THE SUDDEN IMPULSE AT 19/1526Z, BZ WAS NORTHWARD
UNTIL IT TURNED SOUTHWARD AT APPROXIMATELY 20/0000Z AND STORM
CONDITIONS ENSUED.  BZ BECAME NORTHWARD AGAIN AROUND 20/1300Z AND
THE FIELD CALMED TO UNSETTLED LEVELS.  THE PROTON EVENT THAT BEGAN
ON 14 JULY ENDED AT 19/2330Z.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD SHOULD
RETURN TO STORM LEVELS EARLY ON 21 JULY IN RESPONSE TO A SUSPECTED
(NO CORONAGRAPH DATA) MASS EJECTION WITH THE M6 FLARE ON 19 JULY.
MINOR TO MAJOR STORM LEVELS ARE EXPECTED.  ISOLATED PERIODS OF
SEVERE STORMING ARE POSSIBLE.  THE DISTURBANCE SHOULD CONTINUE INTO
22 JULY WITH UNSETTLED TO MINOR STORM LEVELS FORECAST.  QUIET TO
UNSETTLED CONDITIONS ARE EXPECTED ON 23 JULY.  THERE IS A MODERATE
PROBABILITY OF A SOLAR PROTON EVENT DURING THE PERIOD.
III.  EVENT PROBABILITIES 21 JUL-23 JUL
CLASS M    85/80/75
CLASS X    35/30/20
PROTON     35/30/20
PCAF       YELLOW
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           20 JUL 253
PREDICTED   21 JUL-23 JUL  245/235/230
90 DAY MEAN        20 JUL 188
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 19 JUL  010/015
ESTIMATED AFR/AP 20 JUL  038/052
PREDICTED AFR/AP 21 JUL-23 JUL  050/050-025/020-015/015
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 21 JUL-23 JUL
A.  MIDDLE LATITUDES
ACTIVE                25/30/20
MINOR STORM           25/25/15
MAJOR-SEVERE STORM    30/10/05
B.  HIGH LATITUDES
ACTIVE                25/30/20
MINOR STORM           25/25/15
MAJOR-SEVERE STORM    30/10/05