Severe Thunderstorm Warning 43, NWS Paducah, KY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
251 AM CDT SUN JUN 3 2001

MAIN FOCUS FOR NEXT 12 TO 36 HOUR TIME FRAME WILL BE SPATIAL AND
TEMPORAL ALIGNMENT OF RAIN CHANCES ACROSS PAH FORECAST AREA. OF
COURSE...THE LOCATION OF THE WARM FRONTAL BOUNDARY TODAY THROUGH
MONDAY WILL HAVE A STRONG INFLUENCE ON TEMPS/WIND FORECAST.

MINOR TSTM CLUSTER OVER THE SWRN PTN OF THE PAH CWA BTWN 04-05Z SUN
WAS ASSOCIATED WITH EXTREMELY SHARP 925 MB THETA-E GRADIENT AND
40-60KT NW-SELY ORIENTED JETLET AOA 700 MB. THIS FEATURE TRANSLATED
INTO NERN AR AND WRN TN OVERNIGHT. NEW CONVECTION WAS DEVELOPING
OVER NWRN AR...WERE WAA WAS CRANKING UP IN EARNEST. DECENT WAA
ADVECTION HAS ALSO BEEN EVIDENT WITH IR SATL PIX SHOWING EXPANSION
OF CU/AC ACRS KS/AR/MO DURING THE PAST EIGHT HOURS. MOST OF THE LIFT
WAS FOCUSED IN ADVANCE OF NEGATIVELY TILTED TROUGH...WITH CLOSED LOW
NOTED ON 00Z 850 MB HEIGHT CHART OVER WY...WITH SHARPENING WARM
FRONTAL BOUNDARY EXTENDING OVER SRN NE...BISECTING KS FROM
NW-SE...WITH SOME SUGGESTION OF FRONTEGENETIC FORING INTO NERN OK
AND AR.

ANTICIPATE INCREASED LIFT/SATURATION OF SFC-850 MB+ DEEP MSTR AS
WARM AIR ADVECTION CONTINUES TO SPREAD ACROSS MO INTO SWRN IL/WRN KY
TODAY. 00Z UA ANALYSIS SUGGESTED ONE N-S ORIENTED 850 MB MSTR RIDGE
ACRS S CNTRL KS AND INTO CNTRL OK...WITH ANOTHER SW-NELY ORIENTED
FROM NERN TX INTO THE MO BOOTHEEL. THIS SECOND FEATURE WAS
CO-LOCATED WITH A WEAKER SECONDARY THERMAL RIDGE. AT 925 MB...THE
MAIN THETA-E RIDGE WAS LOCATED OVER ERN OK AND WRN MO.  GIVEN THE
INCREASED LOW LVL QG FORCING IN RESPONSE TO THE SHARPENING AND
NEGATIVELY TILTED S/WV MOVING INTO NERN CO AND NWRN KS...THE
AFOREMENTIONED THERMAL/MOISTURE AXES WILL BE ENHANCES WITH
INCREASINGLY UNSTABLE AIR BEING LIFTED NWD FROM THE GULFMEX. 00Z
SOUNDINGS SUGGEST THAT THE 300K LAYER WILL BE THE INITIAL MSTR
TRANSPORT LAYER FOR DEVELOPING CONVECTION TODAY.

AVN HAS CONVERGED WITH ETA SOLN ON DEVELOPMENT AND INTENSIFICATION
OF WARM FRONTAL BOUNDARY THIS AFTERNOON AND TONIGHT...WITH THE
GREATEST FORCING IN THE PAH FORECAST AREA EXPECTED BETWEEN 00Z AND
12Z MON. PRECIPITABLE WATER VALUES FROM BOTH AVN/ETA INCREASE FROM
AROUND 3/4 OF AN INCH TO ALMOST 1.75 INCHES BY 12Z MON...ESPECIALLY
ACRS THE NRN 1/2 OF THE CWA. ANTICIPATE THAT MOISTURE FLUX
CONVERGENCE...LIFT AND STABILITY GRADIENTS ASSOCIATED WITH
APPROACHING S/WV AND ATTENDANT CHANGES IN WIND FIELDS WILL PRODUCE A
NARROW SWATH OF CONVECTION WITH LOCALLY HEAVY RAIN ACROSS SRN
IL...NWRN KY AND EXTREME SWRN IN. I CANNOT RULE OUT ISOLATED ONE TO
TWO INCHES AMOUNTS IN A THREE HOUR PERIOD FROM 06-12Z MON IN AN AREA
BOUNDED BY PINCKNEYVILLE AND GRAND TOWER IL TO THE WEST AND
OWENSBORO AND GREENVILLE KY TO THE EAST.

FOR THE ZONE FORECAST PACKAGE TODAY...MAY MAKE A MINOR TWEEK IN THE
ZONE BOUNDARIES...BUT GENERALLY LIKE THE ARRANGEMENT OF ZONE GROUPS
FROM DAY SHIFT. ANTICIPATE SCATTERED CONVECTION TO OVERSPREAD SERN
MO FIRST...THEN SPREAD N AND E THIS AFTN AND TONIGHT AS WARM FRONT
MOVES NEWD TOWARD THE CWA LATER TODAY AND TONIGHT. ANTICIPATE BEST
THUNDERSTORM/HEAVY RAIN CHANCES WILL OCCUR ALONG THE SRN PTN OF THE
SRN IL/ SWRN IN/NWRN KY ZONE GROUPS. WL NOT MAKE ANY SPECIFIC
MENTION OF SVR POTENTIAL...BUT SUSPECT INITIAL AND GREATEST THREAT
FOR THE PAH FORECAST AREA WILL BE OVER SERN MO.

WL LOOK AT MAV TEMPXS FOR MAX/MINS AND ADJUST ACCORDINGLY TO PCPN
THREAT AND CLOUD COVER.

WL NOT MAKE ANY CHANGES TO EXTENDED PACKAGE AT THIS TIME.

.PAH...NONE.

SMITH