Severe Thunderstorm Warning 111, NWS Paducah, KY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
200 PM CDT TUE MAY 23 2000

PRIMARY FORECAST CHALLENGE IS TIMING POPS WITH MOVEMENT/PLACEMENT OF
WEAK SURFACE TROF(S). LATEST SURFACE ANALYSIS SHOWS WEAK TROF THAT
HELPED FOCUS AM CONVECTION HAS SCOOTED EAST INTO CNTL KY...AND TAKEN
MOST CONVECTION W/IT. WEAK TROF/COLD FRONT STRETCHES FROM NRN IN
INTO CNTL MO...POISED TO ENTER FA LATE TODAY/EARLY TONIGHT AS NEXT
NW FLOW PERTURBATION DROPS SE OUT OF IL.

NEW MODEL RUNS SUGGEST DROPPING WAVE/WEAK FRONT WL ENCOUNTER
SUFFICIENTLY UNSTABLE ENVIRONMENT OVER PAH FA BY 00Z WED. DEW POINT
POOLING OF 70F PLUS NOTED FM NE AR-SEMO-SW IL...WHERE FRONT IS
SAGGING SOUTH TOWARD. 12Z UA ANALYSIS REVEALS NOSE OF 130KT H3 JET
IN DIFLUENT NW FLOW ALOFT PROGGED TO INTERACT W/NE PTNS FA BY
TONIGHT. ONLY INHIBITING FACTOR IS BEST MEAN RH IS CONCENTRATED EAST
OF FA...THOUGH BOTH ETA/NGM BACK-BUILD IT AND POOL IT ALONG/AHEAD OF
WEAK FRONTAL BOUNDARY TONIGHT. LATEST SPC HAS ENTIRE FA IN SLGT RISK
SVR TONIGHT. BELIEVE CONVECTION WL REMAIN SCATTERED WITH HIGHER MEAN
RH EAST...THUS WL RETAIN CHC CATEGORY POPS ENTIRE FA THRU TONIGHT.
WL MAINTAIN CLOSE MONITOR THRU PRESS TIME FOR ANY LAST MINUTE
ADJUSTMENTS.

AFT 24 HOURS IS WHERE MODELS DIVERGE SOMEWHAT. WHILE ENVIRONMENT
REMAINS UNSTABLE WED...LOW LAYER CONVERGENCE DIMINISHES AS SURFACE
FRONT IS DRAGGED EAST. WL THEREFORE BLEED TONIGHT POPS INTO EARLY
WED FAR SRN/ERN PTNS FA...WHERE SPC DAY2 CONTINUES SLGT RISK. WL GO
AHEAD AND DROP POPS OUT NORTH WHERE LOW LAYER WLYS TAKE OVER. ETA
TRIES TO STALL BOUNDARY JUST TO SOUTH AND THEN RETURN IT NORTHWARD
THRU OUR AREA LATE WED NIGHT INTO THU...WHILE NGM IS A LITTLE MORE
AGGRESSIVE W/SOUTHWARD PUSH BUT NONETHELESS HINTS AT A SIMILAR RETURN
NWARD FOR THU. AVN DIFFERS GREATLY FIRST 36 HOURS...BUT BEGINS TO
PICK UP ON ETA/NGM SUGGESTION OF RETURNING BOUNDARY POST 48 HOURS.
AM THUS INCLINED TO TWEEK THU/FRI PTNS FORECAST FOR EARLIER
INTRO/DEPARTURE OF POPS...MORE IN TUNE W/ETA.

TEMPS HAVE RUN BETWEEN FWC/FAN GUIDANCE LAST 24 HOURS. WL GENERALLY
FOLLOW THEIR NOS AS 12Z RUN IS NOT TOO DISSIMILAR.

.PAH...NONE.
DH

ILZ075>078-080>094-INZ081-082-085>088-KYZ001>022-MOZ076-086-087-100-
107>112-114-231830-

THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE PADUCAH KY
1110 AM CDT TUE MAY 23 2000

THIS OUTLOOK PERTAINS TO SOUTHEAST MISSOURI...SOUTHERN ILLINOIS...
SOUTHWEST INDIANA AND WESTERN KENTUCKY...VALID UNTIL 600 AM
WEDNESDAY.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE FOUR-STATE
REGION THIS AFTERNOON AND TONIGHT.

THE AIRMASS REMAINS FAVORABLE FOR THE DEVELOPMENT OF STRONG TO
SEVERE THUNDERSTORMS. AT MID MORNING...A FRONTAL BOUNDARY WAS ACROSS
CENTRAL ILLINOIS INTO CENTRAL MISSOURI. THIS FRONT MOVING SOUTHEAST
ACROSS THE AREA...COMBINED WITH THE EXISTENCE OF NUMEROUS OUTFLOW
BOUNDARIES PRODUCED BY MORNING THUNDERSTORMS...WILL BE THE FOCAL
POINTS FOR RE-DEVELOPMENT.

THE AIRMASS ACROSS THE REGION WILL BE VERY UNSTABLE THIS AFTERNOON.
IN ADDITION...VERTICAL WIND AND SPEED SHEAR REMAIN FAIRLY IMPRESSIVE.
AS A RESULT...THE MAIN THREATS WILL BE LARGE HAIL AND DAMAGING
WIND. BECAUSE THE AIRMASS IS EXPECTED TO BECOME SO UNSTABLE...AND
WIND SHEAR WILL BE SUFFICIENT...A FEW TORNADOES CANNOT BE RULED
OUT.

STORM MOTION IS EXPECTED TO BE SOUTHEAST FROM 35 TO 45 MPH. SPOTTER
ACTIVATION MAY BE REQUESTED THROUGH THE COURSE OF THE AFTERNOON AND
TONIGHT.

NOLES

KYZ016-017-021-022-231700-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PADUCAH KY
1117 AM CDT TUE MAY 23 2000

AT 1115 AM...A STRONG THUNDERSTORM WAS LOCATED JUST SOUTH OF
HOPKINSVILLE MOVING EAST/SOUTHEAST AROUND 40 MPH.

THROUGH NOON...THIS STORM WILL LIKELY AFFECT THE COMMUNITIES OF
PEMBROKE...TRENTON AND GUTHRIE ACROSS SOUTHERN PORTIONS OF CHRISTIAN
AND TODD COUNTIES.

PEA TO MARBLE SIZE HAIL AND GUSTY WIND ARE POSSIBLE WITH THIS STORM.

NOLES

ILZ076>078-083-087>094-INZ081-082-085>088-KYZ001>022-MOZ087-111-112-
114-232030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PADUCAH KY
1150 AM CDT TUE MAY 23 2000

THE SEVERE THUNDERSTORM WATCHES THAT WERE IN EFFECT FOR PORTIONS OF
SOUTHEAST ILLINOIS...SOUTHWEST INDIANA...AND WESTERN KENTUCKY HAVE
BEEN CANCELLED.

THE STORMS THAT PRODUCED SEVERE WEATHER THIS MORNING HAVE DIMINISHED.
HOWEVER...STORMS ARE EXPECTED TO REDEVELOP AGAIN LATE THIS AFTERNOON.
WITH THE ENVIRONMENT NEARLY THE SAME...ANOTHER ROUND OF SEVERE
WEATHER IS POSSIBLE.

THE NWS WILL CONTINUE TO CLOSELY MONITOR AFTERNOON STORM
DEVELOPMENT. STAY TUNED TO YOUR LOCAL BROADCAST MEDIA IN CASE A NEW
WEATHER WATCH IS REQUIRED.

DH