:Product: Weekly Highlights and Forecasts
:Issued: 1999 Jul 27 2112 UT
HIGHLIGHTS OF SOLAR AND GEOMAGNETIC ACTIVITY
19 - 25 JULY 1999

SOLAR ACTIVITY WAS LOW TO HIGH DURING THE PERIOD. HIGH CONDITIONS
WERE EXPERIENCED ON 19 JULY DUE TO AN M5/2N EVENT AT 19/0846UT FROM
REGION 8636 (N20, L=334, CLASS/AREAEAI/330 ON 19 JULY). THIS EVENT
ALSO PRODUCED TYPE II AND IV SWEEPS. REGION 8636 CONTINUED TO GROW
IN SIZE AND COMPLEXITY UNTIL NEAR THE MIDDLE OF THE PERIOD. IT THEN
BEGAN TO SIMPLIFY AND SHOW SIGNS OF DECAY TOWARD THE END OF THE
PERIOD. HIGH CONDITIONS WERE ALSO EXPERIENCED ON 24 JULY. THIS WAS
DUE TO 5 M-CLASS EVENTS THAT DAY. TWO WERE OPTICALLY UNCORRELATED
AND THE OTHER THREE WERE FROM REGION 8645 (S26, L=251, CLASS/AREA
DKO/190 ON 24 JULY). REGION 8645 IS THOUGHT TO BE THE RETURNING
REGION 8611, WHICH PRODUCED MULTIPLE C AND M-CLASS EVENTS DURING ITS
LAST ROTATION. MODERATE CONDITIONS WERE EXPERIENCED ON 23 AND 25
JULY. SOLAR ACTIVITY WAS LOW ON 20-22 JULY. THE ONLY OTHER REGION OF
NOTE WAS REGION 8639 (N38, L=032, CLASS/AREA DAO/230 ON 25 JULY).
THIS REGION PRODUCED AN M2/SF ON 25/1338UT ACCOMPANIED BY TYPE II
AND IV SWEEP FREQUENCY BURSTS.

REAL-TIME SOLAR WIND DATA WERE AVAILABLE FROM THE ADVANCED
COMPOSITION EXPLORER (ACE) SPACECRAFT FOR MOST OF THE PERIOD. SOLAR
WIND VELOCITY SHOWED A STEADY INCREASE FROM 320 TO 490 KM/SEC ON 22
JULY. VELOCITY INCREASED TO OVER 500 KM/SEC ON 23 JULY AND THEN
RETURNED TO NORMAL LEVELS ON 24 JULY.

NO PROTON EVENTS WERE DETECTED AT GEO-SYNCHRONOUS ORBIT DURING THE
PERIOD.

THE GREATER THAN 2 MEV ELECTRON FLUX AT GEO-SYNCHRONOUS ORBIT WAS AT
NORMAL LEVELS.

THE GEOMAGNETIC FIELD WAS MOSTLY QUIET TO UNSETTLED. ISOLATED ACTIVE
CONDITIONS WERE EXPERIENCED ON 21 JULY. MINOR STORM CONDITIONS WERE
EXPERIENCED ON 22/0300-0600UT. THE INCREASED GEOMAGNETIC ACTIVITY
WAS THOUGHT TO HAVE BEEN RELATED TO A HALO CME EARLY ON 19 JULY.

FORECAST OF SOLAR AND GEOMAGNETIC ACTIVITY
28 JULY - 23 AUGUST 1999

SOLAR ACTIVITY IS EXPECTED TO RANGE FROM LOW TO MODERATE LEVELS.
ISOLATED M-CLASS FLARES FROM REGIONS 8636 AND 8645 MAY OCCUR AT ANY
TIME DURING THE PERIOD. THERE WILL ALSO BE A SLIGHT CHANCE FOR A
MAJOR FLARE SOMETIME DURING THE PERIOD.

THERE WILL BE A SLIGHT CHANCE FOR A PROTON EVENT AT GEO-SYNCHRONOUS
ALTITUDE.

THE GREATER THAN 2 MEV ELECTRON FLUX AT GEO-SYNCHRONOUS ALTITUDE IS
EXPECTED TO BE AT  NORMAL TO MODERATE LEVELS DURING MOST OF THE
PERIOD.

GEOMAGNETIC FIELD ACTIVITY IS EXPECTED TO BE AT QUIET TO UNSETTLED
LEVELS DURING MOST OF THE PERIOD, BARRING ANY EARTH-DIRECTED CMES.


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