Severe Thunderstorm Warning 206, NWS Kansas City, MO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
315 PM CDT FRI AUG 16 2002

MAIN FORECAST CONCERN THIS PACKAGE IS TIMING OF FRONT ON SATURDAY.
ETA MODEL IS SLOWER...WITH FRONT STILL IN SOUTHERN PART OF FORECAST
AREA BY 00Z. AVN STAYING MORE CONSISTENT WITH PUSHING FRONT THROUGH
FASTER. THIS WILL HAVE BIG IMPACT ON TEMPERATURES AND STORM
POTENTIAL. WILL TREND TOWARD AVN SOLUTION SINCE ETA INITIALIZATION
HAD PROBLEMS THIS MORNING SO SOME QUESTION OF WHAT EFFECT THAT HAD.
HOWEVER THINK MAV GUIDANCE RUNNING TOO COLD GIVEN FACT THAT
OVERNIGHT LOWS WILL LIKELY STAY WARMER THAN WHAT GUIDANCE IS
SHOWING.

NOT MAKING ANY BIG CHANGES TO GOING FORECASTS SUNDAY THROUGH
TUESDAY. WARM AIR ADVECTION SETS UP SUNDAY NIGHT. WILL EXPAND THE
PRECIPITATION AREA OVERNIGHT...AS AVN SHOWS LOW LEVEL JET PICKS UP
ACROSS ALL OF FORECAST AREA. MAY SEE MCS SET UP AND ROLL EAST ON
MONDAY. THIS MAY LEAVE A BOUNDARY IN AREA MONDAY NIGHT. SOME CONCERN
WITH AVN LEAVING SOME PRECIPITATION IN AREA ON TUESDAY NEAR THIS
BOUNDARY. WILL NOT INTRODUCE POPS AT THIS TIME...BUT SOMETHING TO BE
WATCHED.

IN EXTENDED...WILL ADD SOME PRECIPITATION IN NORTHERN PART OF
FORECAST AREA ON THURSDAY. BIG QUESTION ON THIS UPPER RIDGE SITS
ACROSS SOUTHERN PLAINS AND WAVES WILL BE RIDING OVER THIS RIDGE
WEDNESDAY THROUGH FRIDAY...SO TIMING VERY TOUGH AT THIS POINT. MRF
RUN BRINGS A STRONGER WAVE TOWARD AREA BY 12Z THURSDAY WILL KEY ON
THIS FEATURE FOR TIMING OF THE POPS.

PC

410 AM...

FRONT JUST SOUTH OF A STJ TO IRK LINE CONTINUING TO TRIGGER
SCATTERED SHOWERS AND THUNDERSTORMS IN A MOIST AND UNSTABLE AIR
MASS. MODELS CONTINUE TO INDICATE FRONT TO DISSIPATE IN RESPONSE TO
PRESSURE FALLS IN LEE OF ROCKIES AS STRONG SHORTWAVE TROF MOVES
RAPIDLY EAST INTO NORTHERN ROCKIES. AS A RESULT...EXPECT SHOWER AND
THUNDERSTORM ACTIVITY ACROSS NORTHERN HALF OF COUNTY WARNING AREA TO
GRADUALLY DIMINISH THIS MORNING.

NEXT CONCERN IS SPEED OF NEXT FRONT AND THREAT OF CONVECTION ALONG
FRONT. MODELS ARE CONSISTENT IN DRIVING FRONT INTO EXTREME
NORTHWESTERN MISSOURI BY DAYBREAK AND INTO SOUTHEASTERN ZONES DURING
THE AFTERNOON. SQUALL LINE WILL LIKELY DEVELOP ALONG FRONT IN
NEBRASKA...IOWA AND KANSAS FRIDAY NIGHT WITH MODERATE LINEAR FORCING
AND SHOWALTER INDICES AROUND -6. STRONG 850MB LOW LEVEL JET OF
40-50 KNOT ALSO TO AID DEVELOPMENT. WILL KEEP POPS IN CHANCE
CATEGORY AT THIS TIME DUE TO HAVING SOME CONCERN THAT MODELS MAY
STILL HAVE SOME TROUBLE IN TIMING.

SQUALL LINE WOULD LIKELY PROGRESS QUICKLY THROUGH THE COUNTY WARNING
AREA BY EARLY AFTERNOON. ALTHOUGH THERE IS A STILL A THREAT OF
SEVERE...MAINLY DAMAGING WINDS...THE TIMING OF THIS EVENT...WILL
LIMIT THE COVERAGE AND THE SEVERITY. THE INITIAL SQUALL LINE MAY END
UP BEING THE ONLY SHOW AS IT MAY SHUNT MOST MOISTURE TO THE SOUTH.
HOWEVER...WILL HOLD ON TO THE THREAT THROUGHOUT THE DAY DUE TO
UNCERTAINITY. HOWEVER...WILL REMOVE THREAT FOR THE NIGHTTIME HOURS
EXCEPT FOR THE EVENING HOURS IN THE SOUTH.

OTHERWISE...GUIDANCE TEMPERATURES LOOK OK.

DB

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