Severe Thunderstorm Warning 8, NWS Louisville, KY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
325 AM EST MON JAN 3 2000

MAIN FORECAST CHALLENGES WILL BE PRECIPITATION TRENDS AND POTENTIAL
AMOUNTS THROUGH THE PERIOD.

LATEST SURFACE ANALYSIS INDICATED A QUASI STATIONARY FRONTAL BOUNDARY
EXTENDING FROM CENTRAL ARKANSAS STRETCHING NORTHEAST ALONG AND NORTH
OF THE OHIO RIVER INTO NORTHWEST OHIO. REGIONAL DOPPLER RADAR
INDICATING A WIDE SWATCH OF MODERATE TO OCCASIONALLY HEAVIER RAIN
ALONG THE VICINITY OF THE FRONTAL BOUNDARY. ALL OF THE THUNDER
ACTIVITY REMAINS ACROSS WESTERN PORTIONS OF KY AND SOUTHWEST
INDIANA...WITH RENEWED DEVELOPMENT FURTHER WEST ALONG THE MISSOURI
AND ARKANSAS BORDER.

THE MODELS ARE IN GOOD ENOUGH AGREEMENT FOR OUR REGION TODAY...AND
THUS AS THE SHORT WAVE EJECTS OUT OF THE SOUTHERN PLAINS THERE
SHOULD BE SOME SHORT WAVE RIDGING ACROSS KENTUCKY TODAY...AND THIS
SHOULD HELP TO PUSH THIS BOUNDARY A BIT FURTHER NORTH THIS MORNING.
THE ETA DEPICTS THE HEAVIEST RAIN QUITE WELL NOW WITH INITIAL SURGE
OF SATURATED MEAN H85/H50 RELATIVE HUMIDITY AND QUITE IMPRESSIVE
UPPER LEVEL DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 140 KT
UPPER LEVEL JET STREAK AND MOVES THIS FEATURE ALONG THE OHIO RIVER TO
SOUTHERN OHIO AND AWAY FROM OUR AREA.

MEANWHILE...THIS AFTERNOON AS THE LOW MOVES FROM THE SOUTHERN PLAINS
TO THE MID MISSISSIPPI RIVER VALLEY...THE COLD FRONT WILL DRAW
NEAR...WITH ANOTHER LOBE OF MOISTURE AND ASSOCIATED UPPER LEVEL
DIVERGENCE WILL MOVE INTO OUR AREA.  THUS...WITH INCREASING MOISTURE
AND FAVORABLE DYNAMICS...I/VE OPTED FOR LIKELY POPS THIS AFTERNOON
FOR MOST AREAS.

TONIGHT...AS THE COLD FRONT RACES THROUGH THE STATE...FEEL THERE
WILL BE A DECENT SHOT OF SHOWERS AND THUNDERSTORMS AS 70 KT H85 WIND
ADVECTS HIGH THETA E AIR INTO A POSITION AHEAD OF THE COLD FRONT.
THE UPPER LEVEL DIVERGENCE IS FORECAST TO NOT BE AS STRONG...
NONETHELESS IT SHOULD HELP TO PUMP UP ANY QPF AMOUNTS. LATEST
CONVECTIVE OUTLOOK PEGS AREAS ALONG AND WEST OF INTERSTATE 65 FOR A
SLIGHT RISK OF SEVERE WEATHER...WITH AREAS EAST EXPECTING GENERAL
THUNDER AS ANY SYSTEM WOULD POTENTIALLY WEAKEN BELOW SEVERE LIMITS
IN AN UNFAVORABLE PERIOD OF NIGHT FOR THOSE AREAS.

ON TUESDAY...THE COLD AIR WILL CONTINUE TO FILTER INTO THE REGION...
WITH TEMPERATURES FALLING THROUGH OR INTO THE 30S. WE/RE ESSENTIALLY
DRY SLOTTED IN THE MORNING...WITH WITH WRAP AROUND MOISTURE MOVING
IN DURING THE AFTERNOON...WE FEEL THERE WILL BE A CHANCE OF SNOW
SHOWERS FOR CENTRAL PORTIONS...WITH A CHANCE OF RAIN MIXING WITH
SNOW IN THE EAST BY LATE AFTERNOON.

QPF AMOUNTS ARE SOMEWHAT PROBLEMATIC. AREAS OF NORTH CENTRAL
KENTUCKY AND SOUTH CENTRAL INDIANA HAVE ALREADY RECEIVED ONE TO ONE
AND ONE HALF INCHES OF RAIN WITH THIS FIRST SYSTEM...AND ADDITIONAL
RAINFALL CAN BE EXPECTED THIS MORNING WITH THE INITIAL SURGE.  WITH
ADDED RAINFALL THIS AFTERNOON AND OVERNIGHT...THESE AREAS WOULD
LIKELY APPROACH FLASH FLOOD VALUES...AND WE/LL HAVE TO MONITOR WATER
LEVELS CLOSELY THROUGH THE DAY...HOWEVER AT THIS TIME WE PLAN TO NOT
ISSUE ANY HEADLINES FOR THE ABOVE MENTIONED AREAS. THE DAY SHIFT MAY
NEED TO RE-EVALUATE THE SITUATION WITH ADDITIONAL MODEL GUIDANCE
THIS MORNING. POTENTIAL 'ADDITIONAL' QPF AMOUNTS FOR NORTH CENTRAL
KENTUCKY AND SOUTH CENTRAL INDIANA THROUGH TUESDAY MORNING COULD
RANGE 1 TO 3 INCHES. ELSEWHERE...SOME OF OUR FORECAST AREA HAS NOT
RECEIVED RAINFALL THIS MORNING AND THOSED AREAS THAT HAVE HAS BEEN
QUITE LIGHT.  THUS...FOR ALL REMAINING AREAS...ONE HALF TO ONE AND
ONE HALF INCHES LOOKS ON TARGET FOR A FIRST GUESS THROUGH TUESDAY
MORNING.

.SDF...NONE.

VLD