:Product: Weekly Highlights and Forecasts
:Issued: 1999 Jul 07 2112 UT
HIGHLIGHTS OF SOLAR AND GEOMAGNETIC ACTIVITY
28 JUNE - 04 JULY 1999

SOLAR ACTIVITY WAS AT MODERATE LEVELS DURING MOST OF THE WEEK. THERE
WERE FOUR REGIONS OF INTEREST DURING THE PERIOD. REGION 8598 (N23,
L=328, CLASS/AREA FKI/650 ON 25 JUNE) SHOWED MODERATE MAGNETIC
COMPLEXITY, BUT SLOWLY DECAYED THROUGH THE WEEK. NONETHELESS, IT
MANAGED TO PRODUCE AN M1/SF FLARE AT 30/2012UT AND AN M1/1F AT
01/2143UT, NEITHER OF WHICH WERE IMPRESSIVE IN RADIO ASPECTS. REGION
8602 (N18, L=297, CLASS/AREA DKO/270 ON 02 JULY) GREW SLIGHTLY
DURING THE EARLY PART OF THE PERIOD AND PRODUCED AN M1/SF FLARE AT
29/0510UT ACCOMPANIED BY A TYPE II RADIO SWEEP. REGION 8603 (S15,
L=286, CLASS/AREA FAI/360 ON 27 JUNE) ALSO GREW GRADUALLY DURING THE
FIRST HALF OF  THE PERIOD AND WAS ONE OF THE MOST PRODUCTIVE REGIONS
OF THE PERIOD. IT PRODUCED A FEW M-CLASS FLARES INCLUDING AN M1/1N
AT 29/1913UT, AN M1/1B AT 30/1130UT ASSOCIATED WITH A HALO-CME
(WHICH CAUSED A GEOMAGNETIC DISTURBANCE ON 02 - 03 JULY, SEE THE
SOLAR WIND AND GEOMAGNETIC ACTIVITY DISCUSSIONS BELOW), AN M2/2B
PARALLEL-RIBBON FLARE AT 30/1808UT, AND AN M1/1N AT 01/2331UT. THE
FINAL REGION OF INTEREST WAS 8611 (S25, L=258, CLASS/AREA FAI/420 ON
04 JULY). IT GREW GRADUALLY THROUGHOUT THE PERIOD, DISPLAYED
MODERATE MAGNETIC COMPLEXITY, AND WAS THE MOST FLARE-PRODUCTIVE OF
THE VISIBLE REGIONS. IT PRODUCED AN M3/1N PARALLEL-RIBBON FLARE AT
29/0821UT, AN M2/1N AT 30/0446UT, AN M2/1B AT 02/0138UT, AND AN
M1/SF AT 02/1520UT ASSOCIATED WITH A PARTIAL-HALO CME. SOLAR
ACTIVITY DROPPED TO LOW LEVELS DURING THE LAST TWO DAYS OF THE
PERIOD AS REGIONS 8602, 8603, AND 8611 APPEARED TO STABILIZE. REGION
8598 ROTATED OUT OF VIEW LATE IN THE PERIOD.

REAL-TIME SOLAR WIND DATA WERE AVAILABLE FROM THE ADVANCED
COMPOSITION EXPLORER (ACE) SPACECRAFT FOR MOST OF THE PERIOD. TWO
TRANSIENT SIGNATURES WERE DETECTED DURING THE PERIOD. THE FIRST
OCCURRED ON 28 JUNE AS VELOCITIES INCREASED FROM 550 TO 890 KM/SEC,
DENSITIES BRIEFLY INCREASED TO 18 P/CC, AND IMF BZ TURNED SOUTHWARD
WITH MAXIMUM DEFLECTIONS TO MINUS 08 NT (GSM). THIS TRANSIENT WAS
PROBABLY ASSOCIATED WITH A PARTIAL-HALO CME SEEN ON 24 JUNE. THE
SECOND TRANSIENT STRUCTURE WAS DETECTED EARLY ON 02 JULY AS A SHOCK
PASSED THE SPACECRAFT AT 02/0024UT ACCOMPANIED BY A VELOCITY
INCREASE FROM 480 - 700 KM/SEC, INCREASED PARTICLE DENSITIES, AND
PERIODS OF SOUTHWARD IMF BZ WITH MAXIMUM DEFLECTIONS TO MINUS 08 NT
(GSM). THIS STRUCTURE WAS LIKELY ASSOCIATED WITH THE 30 JUNE
HALO-CME FROM REGION 8603.

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 TO MODERATE LEVELS.

THE GEOMAGNETIC FIELD WAS DISTURBED DURING THE FIRST HALF OF 28 JUNE
WITH ACTIVE TO MAJOR STORM LEVELS DETECTED AT ALL LATITUDES.
ACTIVITY DECLINED TO MOSTLY QUIET LEVELS DURING THE LATTER HALF OF
28 JUNE AND REMAINED SO THROUGH 01 JULY. ANOTHER DISTURBANCE
OCCURRED DURING 02 - 03 JULY WITH ACTIVE TO MINOR STORM LEVELS AND
ISOLATED MAJOR STORM INTERVALS AT HIGH LATITUDES. FIELD ACTIVITY
SUBSIDED TO MOSTLY QUIET LEVELS DURING THE LATTER HALF OF 03 JULY,
THEN REMAINED SO FOR THE BALANCE OF THE PERIOD.

FORECAST OF SOLAR AND GEOMAGNETIC ACTIVITY
07 JULY - 02 AUGUST 1999

SOLAR ACTIVITY IS EXPECTED TO RANGE FROM LOW TO MODERATE LEVELS.
ISOLATED M-CLASS FLARES 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.


.