Tornadoes and Flash Flood in Kansas, June 13, 2001

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DODGE CITY KS
315 PM CDT WED JUN 13 2001

FORECAST CHALLENGES ARE THREAT FOR SEVERE LOCAL STORMS ALL AREAS
TONIGHT AND FRONTAL POSITION, THEN TEMPS THEREAFTER.

UPPER AIR ANALYSIS SHOWS MAIN UPPER TROF TO STILL COME OUT LATER
TONIGHT WITH COLD POOL AND GOOD UVVS. AHEAD OF THE UPPER TROF A COLD
FRONT HAS PUSHED EAST TO ASHLAND TO NEAR SAINT JOHN LINE AND IS
BEGINNING TO STALL OUT BASED ON 88D DATA. THE MODELS STILL HAVE
STRONG CYCLOGENESIS OCCURRING IN SOUTHERN COLORADO AS MAIN UPPER JET
MOVES ACROSS NORTHERN NEW MEXICO THIS EVENING. THIS LOOKS TO BE ON
TARGET AS STRONG PRESSURE FALLS ARE STARTING TO SHOW UP IN THAT
AREA. PRESSURE FALLS WILL HELP THE FRONT TO STALL AND THEN PUSH
BACK WEST AS A WARM FRONT AND MOIST LINE. THE FRONT MAY PUSH BACK
TO A LIBERAL TO JETMORE TO LACROSSE LINE THIS EVENING WITH
THUNDERSTORMS TRYING TO FORM ALONG IT. STRONG MID LEVEL WINDS
APPROACHING 50KTS ARE ALSO FORECAST TO MOVE OUT OVER FRONTAL
BOUNDARY AND WITH GOOD LOW LEVEL SHEAR. A FEW STRONG TORNADOS ARE
POSSIBLE ALONG FRONTAL BOUNDARY AS THE RESULT OF 1) BAROCLINICALLY
INDUCED LOWER TROPOSPHERIC CYCLONIC RELATIVE VORTICITY (SOLENOIDAL
TERM IN THE VORTICITY EQUATION) TILTED ONTO THE VERTICAL, AND
2) ENHANCED DIRECTIONAL VERTICAL WIND SHEAR, RESULTING IN STRONG MID
LEVEL MESOCYCLONES. OF COURSE THAT IS IF CAP IS BROKEN AND
THUNDERSTORMS FORM. RIGHT NOW NO CLOUDS ARE SHOWING UP ALONG THIS
BOUNDARY.

LATER ON TONIGHT MAIN UPPER TROF COMES OUT WITH GOOD UVVS AND
STEEPENING LAPSE RATES. WILL NEED TO CANVAS ALL AREAS WITH 50 TO 60
POPS, AND SOME SEVERE. WIND DIRECTION WILL BE HARD TO FORECAST WITH
FRONTAL BOUNDARY BACKING UP. COLD FRONT WILL THEN RE-SURGE THROUGH
ENTIRE AREA EXCEPT FOR MED LODGE BY 12Z. SEVERE LOCAL STORMS LOOK TO
BE A GOOD BET.

THEN ON THURSDAY THERE MAY BE SOME LINGERING THUNDERSTORMS AND
SHOWERS MAINLY EAST OF A LINE FROM COLDWATER TO PRATT SO WILL JUST
CONTINUE WITH SOME POPS TO COVER. ALSO MAIN UPPER LOW AND PVA STILL
MOVING ACROSS AREA AND HAVE DECIDED TO THROUGH IN A SMALL
THUNDERSTORMS POP IN THE NORTH CWA WITH COLD POOL. OTHERWISE TEMPS
SHOULD BE MUCH COOLER WITH MID 70S TO AROUND 80. WINDS SHOULD BE 20
TO 30 MPH IN THE MORNING THEN DECREASING BY LATE AFTERNOON.

THURSDAY NIGHT INTO FRIDAY THE ATMOSPHERE DRIES OUT AND WINDS
DECREASE. WILL GO WITH LOWS MAINLY IN THE 40S WITH LOW DEWPOINTS
FORECAST IN THE 30S. THEN FOR FRIDAY HIGHS USING FCST SOUNDINGS MID
TO UPPER 80S LOOK REASONABLE AS WARM FRONT RETURNS AND ZONAL FLOW
SETS UP.

EXTENDED DISCUSSION...
MODELS CONTINUE TO SUGGEST RIDGING TAKING PLACE OVER THE CENTRAL
PLAINS LATE THIS WEEKEND INTO EARLY NEXT WEEK. APPEARS THAT A
NORTHWEST FLOW WILL BE PRESENT ACROSS ERN CO/WRN KS SAT INTO EARLY
SUN SO MAY HAVE TO WATCH FOR SOME EMBEDDED WAVES MOVING ALONG THE
FLOW. AT THIS TIME WILL ONLY GO SLT CHANCE LATE SATURDAY AND OPT TO
KEEP FORECAST DRY ON SUNDAY.

CONFIDENCE FROM MONDAY ON DECREASES RAPIDLY WITH ALL MODELS SHOWING
A SLIGHTLY DIFFERENT MOVEMENT OF THE WESTERN CONUS UPPER LEVEL
SYSTEM. FAVORING NO SINGLE MODELS THIS AFTERNOON AND BASED ON
BLOCKING PATTERN DEVELOPING OVER THE NORTH ATLANTIC AND SPLIT FLOW
DEVELOPING OVER THE PACIFIC WILL KEEP CONDITIONS WARM BUT INTRODUCE
POPS BACK INTO THE FORECAST BY MID WEEK.

PRELIMINARY GUIDANCE FOR COORDINATION ONLY. OFFICIAL FORECASTS ARE
CONTAINED WITHIN THE DODGE CITY ZONE FORECAST.

DDC 057/078 049/086 055 510
GCK 055/077 048/086 053 510
EHA 055/078 048/089 055 510
LBL 055/078 049/088 055 510
HYS 059/076 048/083 054 620
P28 066/080 055/086 058 630

.DDC...NONE.

KRUSE/RBS