Severe Thunderstorm Warning 270, NWS Louisville, KY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
345 AM EST SAT DEC 16 2000

MAIN SHORT TERM CONSIDERATION WILL BE THE POTENTIAL FOR HEAVY RAIN
TODAY IN THE NORTH AND STRONG THUNDERSTORMS DEVELOPING ACROSS THE
CWFA THIS AFTERNOON.

LATEST WV LOOP SHOWS A WELL DEFINED MCS DEVELOPING OVER THE CWFA. IT
ALSO APPEARS THAT THEIR IS NICE DEFORMATION ZONE SETTING UP OVER
SOUTHERN INDIANA. THIS IS ALSO BEING ENHANCED BY THE RIGHT ENTRANCE
REGION OF THE UPPER LEVEL JET FOCUSED IN IL AND MO. THE RUC SHOWS
THE NOSE OF THE LOW LEVEL JET FOCUSING FURTHER EAST...BUT IT ALSO
SHOWS THE GRADIENT OF THE 850 MB THETA IN SOUTHERN INDIANA AND
NORTHERN KENTUCKY THROUGH THE EARLY AFTERNOON. AT THAT TIME...IT
APPEARS THE UPPER LEVEL SYSTEM CURRENTLY DIGGING THROUGH THE
SOUTHERN PLAINS SHIFTS INTO CENTRAL AND SOUTHERN KENTUCKY AND GIVES
THESE AREAS A GOOD POTENTIAL FOR SEVERE WEATHER.

AFTER COORDINATING  WITH SEVERAL OFFICES IT APPEARS THAT WE WILL
LEAN WITH A FFA FOR THE NORTHERN PART OF OUR CWFA..ACCORDING THE
LATEST SWODY1 CENTRAL KENTUCKY MAY SEE A FAST MOVING SQUALL LINE
DEVELOP THIS AFTERNOON AHEAD OF THE DRY SLOT. THIS MAY GIVE THE AREA
THE POTENTIAL FOR WIND DAMAGE AND ISOLATED TORNADOES.

TONIGHT LOOKS TO BE RATHER NASTY. MODELS HAVE SHOWN THAT THIS UPPER
LEVEL SYSTEM IS TRYING TO DIG A LITTLE FURTHER SOUTH AND SLOWER THAN
PREVIOUS RUNS. WE ARE GOING TO BUY THE ETA/AVN SOLUTION...BECAUSE THEY
DO BECOME A LITTLE MORE PROGRESSIVE WITH THIS SYSTEM AFTER THE
ENERGY DIVES INTO THE TROF. THAT SEEMS TO BE THE MORE REASONABLE
SOLUTION SINCE THE FAST FLOW WILL MOST LIKELY EJECT THIS SYSTEM OUT
QUICKLY WHICH WAS SIMILAR TO THE LAST EVENT. THIS SYSTEM ALSO SHOWS
A LOT MORE NEGATIVE TILT...WHICH WILL BE SLOWER IN BRINGING TO THE
COLDER TEMPERATURES ALOFT AND CHANGING THE RAIN TO SNOW.
HOWEVER...WITH THE SUFACE SYSTEM PASSING THROUGH FAIRLY QUICKLY WE
SHOULD SEE COLD AIR UNDERCUTTING THE UPPER LEVEL SYSTEM AND CAUSE A
RAPID BUT STEADY DROP IN TEMPERATURES AT THE BOUNDARY LAYER. A WIND
ADVISORY STILL COULD BE IN ORDER...BUT AT THIS POINT I WOULD HATE TO
MAKE THE CALL THIS EARLY SINCE THE MODELS SHOW BULK OF THE STRONGER
WINDS FOCUSED FURTHERN SOUTH OVERNIGHT. HOWEVER...IF THE UPPER LEVEL
TROF PASSES THROUGH AND THE SURFACE LOW KICKS FURTHER NORTH WE
SHOULD HAVE NO PROBLEM REACHING WIND CHILL AND WIND ADVISORY
CRITERIA. FOR NOW WE WILL LET THE DAY SHIFT SORT THIS MATTER OUT. WE
WILL CONTINUE TO HEADLINE THE WIND IN THE ZONES.

TOMORROW THE MODELS CONTINUE TO SHOW STRONG COLD AIR ADVECTION
BUILDING INTO THE AREA DURING THE MORNING. THIS WILL BE ACCOMPANIED
BY THE ROTATING COMMA HEAD SHIFTING BEHIND THE UPPER LEVEL TROF.
WOULD NOT EXPECT ANY SIGNIFICANT SNOW AMOUNTS WITH THIS DUE TO THE
MODELS SHOWING THE DEEPER MOISTURE FOCUSED FURTHERN NORTH. THUS...WE
KEPT SNOW AMOUNTS ON THE LIGHT SIDE. TEMPERATURES SHOUuLD DROP OR
REMAIN STEADY OVER MOST OF THE AREA.

.SDF...FLASH FLOOD WATCH EXTREME NORTH CENTRAL KENTUCKY AND SOUTHERN
INDIANA

COX

INZ076>079-083-084-089>092-KYZ023>043-045>049-053>057-061>067-
070>078-081-082-162145-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LOUISVILLE KY
1155 AM EST SAT DEC 16 2000

...A WILD WEATHER WEEKEND CONTINUES FOR SOUTH CENTRAL INDIANA
AND CENTRAL KENTUCKY WITH STRONG THUNDERSTORMS POSSIBLE THIS
AFTERNOON AND NEAR BLIZZARD CONDITIONS LATE TONIGHT...

LOW PRESSURE OVER NORTHERN MISSISSIPPI WILL CONTINUE TO STRENGTHEN
AND LIFT NORTHEAST ACROSS OUR REGION THIS AFTERNOON AND TONIGHT.
SOUTHERLY WINDS AHEAD OF THIS SYSTEM WILL DRAW WARM...MOIST AIR
NORTHWARD. AN ARCTIC FRONT WILL CRASH INTO THE REGION THIS EVENING.
AS A RESULT...MORE SHOWERS AND THUNDERSTORMS WITH HEAVY RAIN WILL
DEVELOP THIS AFTERNOON. SOME OF THE STORMS MAY PRODUCE WIND DAMAGE
DUE TO AN UNSTABLE AIR MASS.

AFTER THIS FRONT PASSES THROUGH THE AREA THIS EVENING...THE
RAIN WILL CHANGE OVER TO SNOW FROM WEST TO EAST BEGINNING AROUND
MIDNIGHT. TOTAL SNOW ACCUMULATIONS WILL MOST LIKELY RANGE FROM 1 TO
3 INCHES THROUGH SUNDAY MORNING. STRONG WEST WINDS AND SHARPLY
COLDER TEMPERATURES ARE ALSO ANTICIPATED. SUSTAINED WIND SPEEDS OF 25
TO 35 MPH WITH GUSTS TO 45 MPH ARE POSSIBLE WHICH WILL CAUSE BLOWING
AND DRIFTING SNOW. TEMPERATURES WILL DROP FROM THE 50S THIS AFTERNOON
TO NEAR 20 BY SUNDAY MORNING. THESE TEMPERATURES COMBINED WITH
STRONG WINDS WILL PRODUCE WIND CHILLS BETWEEN 10 AND 20 BELOW ZERO
BY SUNDAY MORNING.

THE COMBINATION OF VERY LOW VISIBILITIES PRODUCED BY FALLING AND
BLOWING SNOW LATE TONIGHT MAY RESULT IN NEAR BLIZZARD CONDITIONS
AFTER MIDNIGHT AND EARLY SUNDAY MORNING.

IF YOU PLAN ON TRAVELING LATE TONIGHT OR EARLY SUNDAY...BE
PREPARED FOR LIFE THREATENING CONDITIONS IF YOU ARE CAUGHT
OUTSIDE. PRACTICE YOUR WINTER SAFETY RULES...KEEP A FLASHLIGHT...
FOOD AND WATER IN YOUR CAR IN CASE OF EMERGENCY.

KIRKPATRICK