:Product: Weekly Highlights and Forecasts
:Issued: 1999 Jun 08 2112 UT
HIGHLIGHTS OF SOLAR AND GEOMAGNETIC ACTIVITY
31 MAY - 06 JUNE 1999

SOLAR ACTIVITY RANGED FROM LOW TO MODERATE LEVELS. NUMEROUS C-CLASS
SUBFLARES OCCURRED DURING THE PERIOD FROM A VARIETY OF SMALL- TO
MODERATE-SIZED ACTIVE REGIONS. ACTIVITY ROSE TO MODERATE LEVELS
DURING 03 - 04 JUNE DUE TO ISOLATED M-CLASS FLARES FROM REGION 8562
(S16, L=292, CLASS/AREA DKI/420 ON 03 JUNE) AND REGION 8552 (N19,
L=346, CLASS/AREA EKO/360 ON 27 MAY). ONE OF THESE FLARES, AN
IMPULSIVE M3/2B FROM REGION 8552 AT 04/0703UT, WAS ASSOCIATED WITH A
TYPE IV RADIO SWEEP, A 360 SFU TENFLARE, A PARTIAL-HALO CME, AND A
PROTON EVENT.

REAL-TIME SOLAR WIND DATA WERE AVAILABLE FROM THE ADVANCED
COMPOSITION EXPLORER (ACE) SPACECRAFT FOR MOST OF THE PERIOD. A
SMALL SHOCK PASSED THE SPACECRAFT AT ABOUT 02/2035UT. THE FOLLOWING
CHANGES WERE ASSOCIATED WITH THE SHOCK PASSAGE: A BRIEF DENSITY
INCREASE TO 13 P/CC, A VELOCITY INCREASE FROM 380 TO 440 KM/SEC, AND
SOUTHWARD IMF BZ DEFLECTIONS TO MINUS 11 NT (GSM). NO SIGNIFICANT
DISCONTINUITIES WERE NOTED IN THE SOLAR WIND FLOW DURING THE
REMAINDER OF THE PERIOD.

TWO GREATER THAN 10 MEV PROTON EVENTS WERE DETECTED AT
GEO-SYNCHRONOUS ORBIT DURING THE PERIOD. THE FIRST BEGAN AT
02/0245UT, REACHED A MAXIMUM OF 48 PFU AT 02/1010UT, AND ENDED AT
03/1410UT. THIS EVENT WAS PROBABLY ASSOCIATED WITH A FLARE ON THE
FAR SIDE OF THE SUN. THE SECOND EVENT BEGAN AT 04/0925UT, REACHED A
MAXIMUM OF 64 PFU AT 04/1055UT, AND ENDED AT 05/0515UT. THIS EVENT
WAS ASSOCIATED WITH THE M3/2B FLARE MENTIONED ABOVE.

THE GREATER THAN 2 MEV ELECTRON FLUX AT GEO-SYNCHRONOUS ALTITUDE WAS
AT NORMAL LEVELS DURING MOST OF THE PERIOD.

THE GEOMAGNETIC FIELD WAS DISTURBED DURING 02/2100 - 03/0300UT WITH
UNSETTLED TO ACTIVE LEVELS DETECTED AT ALL LATITUDES. THIS
DISTURBANCE FOLLOWED THE SHOCK PASSAGE MENTIONED ABOVE. THE FIELD
WAS AT QUIET TO UNSETTLED LEVELS DURING THE REST OF THE PERIOD.

FORECAST OF SOLAR AND GEOMAGNETIC ACTIVITY
09 JUNE - 05 JULY 1999

SOLAR ACTIVITY IS EXPECTED TO RANGE FROM LOW TO MODERATE LEVELS.
ISOLATED M-CLASS FLARES ARE EXPECTED DURING THE PERIOD. THERE WILL
ALSO BE A SLIGHT CHANCE FOR A MAJOR FLARE SOMETIME DURING THE
PERIOD.

NO SIGNIFICANT PROTON FLUX ENHANCEMENTS ARE EXPECTED AT
GEO-SYNCHRONOUS ALTITUDE.

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

GEOMAGNETIC FIELD ACTIVITY IS EXPECTED TO INCREASE TO UNSETTLED TO
ACTIVE LEVELS AROUND 14 AND 21 JUNE DUE TO RECURRENT CORONAL HOLE
EFFECTS. OTHERWISE, THE FIELD IS EXPECTED TO BE AT QUIET TO
UNSETTLED LEVELS, BARRING ANY EARTH-DIRECTED CMES.


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