Flash Flooding and Hail in Missouri, May 11 to 12, 2002

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
925 PM CDT FRI MAY 10 2002

925 PM...
EXPCD ELEVATED CNVTN TO BLOSSOM FM NCNTRL THRU E CNTRL KS THIS EVE
IN RGN OF STG H8/H7 THETAE ADVCTN...AND LTST RADAR TRENDS SUPPORT
THIS. FEEL CONFIDENT ENUF TO BUMP POPS IN WRN HLF CWA TO CATEGORICAL
VALUES. ALSO BUMP POPS UP TO LIKELY CAT FOR SAT MRNG ACRS NRN HLF
CWA...AND THEN ONLY MENTION CHC IN NW FOR LT AFTN REDVLPMT.

MJ

433 PM...
MAIN FCST CONCERN IS CURRENTLY PRECIP CHCS AND INTENSITY TONIGHT
THRU SUNDAY. STRONG WAA AHEAD OF DEVELOPING LOW IS PROVIDING ENOUGH
LIFT FOR TSRA SOUTHERN KANSAS. THIS AREA MATCHES UP WELL WITH
STRONGEST UPGLIDE ON ETA 300K ISENTROPIC SFC. APPEARS THIS IS ALSO
WHERE THE 850MB WARM FRONT IS SETTING UP. TSRA SHOULD CONTINUE TO
SPREAD ACROSS FCST AREA THIS EVENING...AS THE WARM FRONT MOVES
NORTH. MAY SEE A BREAK IN THE THUNDERSTORM ACTIVITY AFTER MIDNIGHT.
NOSE OF LOW LEVEL JET SHOULD SPARK ADDITIONAL TSRA OVER CEN
KS...WHICH WOULD MOVE ACROSS THE FCST AREA LATE TONIGHT. SEVERE
THREAT SEEMS MINIMAL...HOWEVER AN ISOLATED HAIL REPORT MAY NOT BE
OUT OF THE QUESTION.

BEST CHC FOR SEVERE STORMS STILL APPEARS TO BE SAT EVENING/NIGHT.
SHOULD SEE SOME WARMING DURING THE AFTERNOON...WHICH WOULD AID IN
THE DESTABOLIZATION. ALSO STILL EXPECT TSRA TO DEVELOP INTO MCS SAT
NIGHT...BRINGING ADDITIONAL HEAVY RAIN TO THE ALREADY SOGGY GROUND.
NEXT FEW SHIFTS WILL HAVE TO LOOK INTO POSSIBLE FLOOD WATCH FOR SAT
NIGHT. FRONT MOVES THROUGH SAT NIGHT/SUNDAY. EXPECT SHOWERS TO END
SUN/SUN EVENING.

1020 AM...
FOR THE EXTENDED PERIOD (MON-FRI)...MODELS IN AGREEMENT WITH PATTERN
THRU WED...WITH SOME DIVERGENCE IN SOLUTIONS THEREAFTER. HAVE GONE
WITH BLEND OF EC AND NCEP ENSEMBLES...AS AVN SEEMS TOO QUICK TO
EJECT PAC NW SHORTWAVE LATE IN THE WEEK. SHORTWAVE TROUGH LOOKS TO
BE EAST OF CWA BY MON AS SFC RIDGE BUILDS INTO REGION. HAVE LOWERED
MAX TEMPS MON AS H85 TEMPS IN THE 4C TO 6C RANGE...SUPPORTING LOW TO
MID 60S ASSUMING BL MIXES THIS DEEP. OTHERWISE HAVE GONE WITH
GRADUAL WARMING TREND THRU THURS AS CWA REMAINS DOWNSTREAM FROM H5
RIDGE AXIS. MODELS BRING UPPER LOW INTO PAC NW WED...RELOADING W
COAST LONGWAVE TROUGH. PER NCEP ENSEMBLES...EXPECT WARM FRONT TO SET
UP SOMEWHERE ACROSS KS/MO THURS NIGHT INTO FRI...SO HAVE INTRODUCED
30 POPS DURING THIS TIME PERIOD.

MS

440 AM...
WARM AIR ADVECTION ALREADY PRODUCING MID-HIGH LEVEL CLOUDS
ACROSS OKLAHOMA...AND EXPECT CLOUDS TO INCREASE ACROSS AREA
TODAY.  MAINTAINED CHANCE OF SHRA ACROSS SW PART OF FOR
LATE THIS AFTERNOON...AND ADDED CHANCE OF SPRINKLES AS FAR
NORTH AS THE MISSOURI RIVER.  WITH CLOUDS AND EASTERLY FLOW...
DID NOT WARM THINGS UP TOO MUCH TODAY...UNDERCUTTING GUIDANCE
SLIGHTLY.

UPPER FLOW BECOMES MORE DIFLUENT TONIGHT...WITH PIECES OF
SOUTHWEST SHORTWAVE ROTATING ACROSS AREA OVERNIGHT. STRONG
ISENTROPIC LIFT...SUPPORTED BY 50KT LLJ...WILL TRANSPORT HIGH THETAE
AIR INTO REGION...WITH PRECIPITABLE WATER VALUES RISING ABOVE ONE
INCH.  GIVEN MODEST MID LEVEL INSTABILITY...KEPT LIKELY TSRA ACROSS
AREA TONIGHT.  BY SATURDAY...PRECIP ASSOCIATED WITH WARM FRONT WILL
LIFT INTO NORTHEAST PART OF FORECAST AREA...WITH PRECIP TAPERING
OFF ACROSS THE REMAINDER OF AREA. NUDGED TEMPERATURES UP A BIT...
AS EXPECT WELL SEE A LITTLE MORE SUN.  ABUNDANT LOW LEVEL MOISTURE
SHOULD KEEP TEMPERATURES FROM GETTING TOO OUT OF HAND...WITH
ETA/AVN MOS VALUES LOOKING REASONABLE. AS SHORTWAVE LIFTS OUT OF SW
ON SATURDAY...LIKELY WILL SEE TSRA FIRE ALONG COLD FRONT DURING
THE AFTERNOON...EVOLVING INTO MCS THAT WILL ROLL ACROSS FORECAST
AREA SATURDAY NIGHT.  FRONTAL BOUNDARY WILL BECOME QUASI-STATIONARY
SOMEWHERE ACROSS THE FORECAST AREA SATURDAY NIGHT...SO EXPECT RAIN
AND THUNDERSTORMS TO CONTINUE ACROSS AREA ON SUNDAY.  DROPPED
TEMPERATURES A LITTLE...AS CLOUDS...EVAP COOLING WONT ALLOW
MUCH OF A WARMUP.

SF

.EAX...
KS...NONE.
MO...NONE.