FXUS63 KEAX 071133
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
533 AM CST MON DEC 7 2009

...UPDATED AVIATION DISCUSSION...

.DISCUSSION...

FOCUS CONTINUES TO BE ON THE UPCOMING WINTER STORM SYSTEM. LITTLE 
HAS CHANGED WITH THE LATEST MODEL RUNS. CONSENSUS CONTINUES TO TAKE 
THE TRACK OF HEAVIEST SNOW ACROSS EXTREME NORTHEAST KANSAS AND 
NORTHWEST INTO NORTH CENTRAL MISSOURI. BROAD SCALE LIFT IS EXPECTED 
TO DEVELOP OVER KANSAS BY THIS EVENING...SPREADING A LARGE PORTION 
OF MISSOURI THROUGH TONIGHT. EXPECT FORECAST SOUNDINGS SHOW TEMP 
PROFILE SUPPORTIVE OF SNOW AT THE ONSET OF PRECIPITATION. SNOW 
SHOULD MOVE INTO NORTHEAST KANSAS AND NORTHWEST MISSOURI DURING THE 
EVENING HOURS...THEN OVERSPREADING ALL BUT POSSIBLY CENTRAL MISSOURI 
BY TUESDAY MORNING. RELATIVELY MINOR...IF ANY...SNOW ACCUMULATIONS 
ARE EXPECTED OVERNIGHT TONIGHT. HOWEVER DEEP ISENTROPIC ASCENT WILL 
INCREASE RAPIDLY TUESDAY MORNING AND CONTINUE THROUGHOUT THE DAY.

QUESTIONS REMAIN WITH PRECIP TYPE MAINLY ALONG AND SOUTH OF A KANSAS 
CITY TO MOBERLY LINE. 00Z MODEL RUNS ONCE AGAIN BRING WARM AIR WELL 
NORTH INTO THE FORECAST AREA. BUT TO ACCOUNT FOR POSSIBLE 
UNDERESTIMATION BY THE MODELS OF THE AMOUNT OF COLD AIR IN 
PLACE...HAVE GONE WITH A WINTRY MIX OF RAIN/SNOW/SLEET FOR EAST 
CENTRAL KANSAS ACROSS CENTRAL MISSOURI.

SNOW AMOUNTS ARE THE BIG QUESTION ACROSS THE NORTHERN SECTIONS OF 
THE FORECAST AREA. MIXING RATIOS THROUGHOUT TUESDAY DURING THE 
ISENTROPIC LIFT TYPE SNOW ARE STILL EXPECTED TO BE IN THE 3-4 G/KG 
RANGE. THEN AS THE SYSTEM WRAPS UP OVER THE REGION TUESDAY 
NIGHT...STRONG DYNAMIC LIFT OCCURS. CONSIDERING THE LENGTH OF TIME 
OF SNOWFALL...UPWARDS OF 10 INCHES REMAINS POSSIBLE ACROSS FAR 
NORTHWEST MISSOURI...WITH LESSER AMOUNTS TO THE SOUTH. 6 INCH LINE 
STILL LOOKS TO CUT ACROSS KANSAS CITY NORTHEAST ACROSS THE 
MACON-KIRKSVILLE AREA. WATCH AREA STILL LOOKS GOOD SO NO ADJUSTMENTS 
MADE AT THIS POINT.

WEDNESDAY CONTINUES TO LOOK BITTERLY COLD AND VERY WINDY. EXPECTING 
ANY SNOW WHICH FALLS TO BE BLOWING AROUND AND SIGNIFICANTLY REDUCING 
VISIBILITIES ACROSS THE NORTHERN HALF OF THE CWA.

&&

.AVIATION...

CEILINGS HAVE RISEN TO MVFR CONDITIONS THIS MORNING AS PRECIP
CONTINUES TO PUSH EAST OF THE TERMINALS. EXPECT CEILINGS TO GRADUALLY
RISE THROUGH DAY...REMAINING MAINLY IN MVFR RANGE ALTHOUGH CANNOT
RULE OUT VFR CONDITIONS FOR A BRIEF PERIOD THIS AFTERNOON.
NEVERTHELESS...WILL HOLD AROUND 2500 FT HEADING INTO THE EVENING AS
CONFIDENCE AT THIS POINT IS LOW. PRESSURE FALLS ALONG THE LEE OF THE
ROCKIES WILL INDUCE INCREASING LLVL FLOW THIS EVENING AND TONIGHT.
THIS SHOULD LEAD TO INCREASING ISENTROPIC ASCENT...LOWER OF CLOUD
BASES...AND HIGHER PRECIP CHANCES DURING THIS TIME FRAME. STILL A
LITTLE UNCERTAIN AS TO THE ONSET OF PRECIP AS WAA REGIME MAY BEGIN
EARLIER THAN ANTICIPATED. WILL INCLUDE A PROB GROUP NEAR 2-3Z AND
MORE SUSTAINED PRECIP BEGINNING 6-8Z. BUFR FORECAST SOUNDINGS INDICATE
THE INITIAL WAVE OF WAA PRECIP SHOULD REMAIN AS SNOW AT ALL TERMINALS
THROUGH THE TAF FORECAST TIME FRAME.

DEROCHE

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT 
     FOR MOZ001>008-011>017-020>025-028.

KS...WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT 
     FOR KSZ025-102-103.

&&

$$