:Product: Weekly Highlights and Forecasts
:Issued: 2000 Jan 25 2112 UT
HIGHLIGHTS OF SOLAR AND GEOMAGNETIC ACTIVITY
17 - 23 JANUARY 2000

SOLAR ACTIVITY FLUCTUATED BETWEEN LOW AND MODERATE LEVELS. REGION
8831 (S18, L = 130, CLASS/AREA EAO/270 ON 17 JANUARY) SHOWED GRADUAL
GROWTH DURING 17 - 18 JANUARY AND PRODUCED A LONG-DURATION M3/1N
PARALLEL-RIBBON FLARE AT 18/1727UT WITH ASSOCIATED TYPES II AND IV
RADIO SWEEPS AND A HALO-CME. THIS REGION ALSO PRODUCED AN M1/SF
FLARE AT 22/1801UT DURING A PERIOD OF GRADUAL DECAY THAT BEGAN ON 19
JANUARY. REGION 8824 (S13, L = 173, CLASS/AREA FKI/430 ON 13
JANUARY) PRODUCED AN M1/SF FLARE AT 18/1008UT ALTHOUGH IT GRADUALLY
DECAYED UNTIL IT CROSSED THE WEST LIMB ON 21 JANUARY. AN OPTICALLY
UNCORRELATED M1 X-RAY FLARE OCCURRED AT 21/0648UT. ACTIVITY DROPPED
TO LOW LEVELS ON THE LAST DAY OF THE PERIOD WITH THE DISK POPULATED
BY TEN MOSTLY SMALL REGIONS, ALL OF WHICH WERE EITHER STABLE OR
DECAYING.

REAL-TIME SOLAR WIND DATA WERE AVAILABLE FROM THE NASA ADVANCED
COMPOSITION EXPLORER (ACE) SPACECRAFT FOR MOST OF THE PERIOD. TWO
TRANSIENT SIGNATURES WERE OBSERVED DURING THE PERIOD. THE FIRST
OCCURRED ON 20 JANUARY WITH MINOR INCREASES IN VELOCITY AND DENSITY,
A SHIFT TO A POSITIVE-POLARITY SOLAR SECTOR, AND PERIODS OF
SOUTHWARD IMF BZ WITH DEFLECTIONS TO MINUS 13 NT (GSM). THE SECOND
OCCURRED DURING 22 - 23 JANUARY AND WAS CHARACTERIZED BY A MINOR
VELOCITY INCREASE, INCREASED DENSITIES (PEAKS TO 37 P/CC), VARAIBLE
SOLAR SECTOR ORIENTATION, AND SUSTAINED SOUTHWARD IMF BZ WITH
DEFLECTIONS TO MINUS 18 NT. SOLAR WIND CONDITIONS WERE NOMINAL
DURING THE REST OF THE PERIOD.

THERE WAS A MINOR GREATER THAN 10 MEV PROTON ENHANCEMENT AT
GEOSYNCHRONOUS ORBIT DURING 18 - 20 JANUARY IN THE WAKE OF THE M3/1N
FLARE OF 18 JANUARY.

THE GREATER THAN 2 MEV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT WAS AT
NORMAL TO MODERATE LEVELS DURING THE PERIOD.

THE GEOMAGNETIC FIELD WAS MOSTLY QUIET DURING 17 - 19 JANUARY. A
MINOR DISTURBANCE OCCURRED DURING 20 JANUARY WITH UNSETTLED TO
(BRIEF) ACTIVE PERIODS DETECTED AT ALL LATITUDES. ACTIVITY DROPPED
TO QUIET LEVELS DURING 21 JANUARY. ANOTHER DISTURBANCE OCCURRED
DURING 22 - 23 JANUARY WITH UNSETTLED TO MINOR STORM LEVELS, THOUGH
MOST MINOR STORM LEVELS WERE LIMITED TO HIGH LATITUDES. BOTH
DISTURBANCES WERE DUE TO CORONAL TRANSIENTS (SEE THE SOLAR WIND
DISCUSSION ABOVE).

FORECAST OF SOLAR AND GEOMAGNETIC ACTIVITY
26 JANUARY - 21 FEBRUARY 2000

SOLAR ACTIVITY IS EXPECTED TO RANGE FROM LOW TO MODERATE LEVELS
DURING THE PERIOD. OCCASIONAL C-CLASS FLARES ARE LIKELY THROUGHOUT
THE PERIOD.  AN INCREASING TREND IS EXPECTED TO BEGIN ON 05 FEBRUARY
WITH ISOLATED M-CLASS FLARES POSSIBLE THROUGH THE REMAINDER OF THE
PERIOD DUE TO THE ANTICIPATED RETURN OF PREVIOUSLY ACTIVE REGIONS.

NO PROTON EVENTS ARE EXPECTED AT GEOSYNCHRONOUS ORBIT.

THE GREATER THAN 2 MEV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT IS
EXPECTED TO BE AT NORMAL TO MODERATE LEVELS THROUGH 27 JANUARY. HIGH
FLUX LEVELS WILL BE POSSIBLE DURING 28 JANUARY - 06 FEBRUARY. NORMAL
TO MODERATE FLUXES ARE EXPECTED FOR THE REST OF THE PERIOD.

GEOMAGNETIC FIELD ACTIVITY IS EXPECTED TO BE AT QUIET TO UNSETTLED
LEVELS ON 26 JANUARY. ACTIVE TO MINOR STORM LEVELS WILL BE POSSIBLE
DURING 27 JANUARY - 01 FEBRUARY DUE TO RECURRENT CORONAL HOLE
EFFECTS. ACTIVE LEVELS WILL ALSO BE POSSIBLE DURING 07 FEBRUARY DUE
TO CORONAL HOLE EFFECTS. QUIET TO UNSETTLED LEVELS ARE EXPECTED FOR
THE BALANCE OF THE PERIOD, BARRING AN EARTH-DIRECTED CME.


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