FXUS63 KSGF 221153
AFDSGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
553 AM CST TUE DEC 22 2009

...UPDATE TO AVIATION...

.DISCUSSION...

FORECAST CHALLENGES DEAL WITH TEMPERATURES THE NEXT FEW DAYS IN
WARM AIR ADVECTION...FOLLOWED BY PRECIP CHANCES AND POTENTIALLY
HEAVY RAINFALL TOWARDS MIDWEEK.

CURRENTLY...SOUTHERLY WINDS AND WARM AIR ADVECTION UNDERWAY THIS
MORNING WITH CURRENT TEMPERATURES IN OKLAHOMA AND ARKANSAS IN THE
LOW TO MID 50S. EASTERN COUNTIES STILL EXPERIENCING AN EASTERLY
WIND FLOW WITH COLDER TEMPERATURES OUT THAT WAY. NEED TO WATCH FOR
SOME POSSIBLE DENSE FOG AROUND THE WEST PLAINS AREA THIS MORNING
AS AN AREA OF STRATUS CONTINUES TO DEVELOP AROUND THE BOOT HEEL
AREA. WATER VAPOR IMAGERY SHOWING OUR MID WEEK STORM SYSTEM
CONTINUING TO PUSH INTO THE ROCKIES. GULF MOISTURE BEGINNING TO BE
PULLED NORTH WITH MID 50 DEWPOINTS BEING OBSERVED ACROSS EAST
CENTRAL TEXAS THIS MORNING.

FOR TODAY...ANOTHER WARM AND DRY DAY AS WAA CONTINUES...SHOULD SEE
TEMPERATURES SIMILAR TO YESTERDAYS HIGHS ACROSS OUR WESTERN
COUNTIES AND SEVERAL DEGREES WARMER ACROSS OUR EASTERN COUNTIES.
850MB TEMPERATURES EXPECTED TO CLIMB TO AROUND +7C THIS
MORNING. HAVE GONE ABOVE MAV MOS GUIDANCE AS IT LOOKS TO BE TOO
COLD AND HAVE TRENDED MORE TOWARDS NAM MOS GUIDANCE FOR
TEMPERATURES TODAY. HEATING MAY BE OFFSET BY INCREASING HIGH
CLOUDINESS SOME THOUGH. KEPT THE FORECAST DRY FOR MOST OF THE DAY
AS ANY LOW LEVEL MOISTURE GETS USED UP TO SATURATE THE DRY LAYERS.
PRECIP EXPECTED TO BEGIN THIS EVENING AS STRONG ISENTROPIC LIFT
BEST SEEN AT THE 290 AND 295K PRESSURE SURFACES DEVELOPS OVER
SOUTHERN MISSOURI AND SPREADS NORTH. ALL AREAS SHOULD BE SEEING
RAINFALL BY WEDNESDAY MORNING.

BY WEDNESDAY MORNING...SURFACE LOW EXPECTED TO BE POSITIONED OVER
CENTRAL OKLAHOMA WITH WARM FRONT TO OUR NORTH ACROSS CENTRAL
MISSOURI. BEST INSTABILITY LOOKS TO BE WEDNESDAY AFTERNOON AND
EVENING WITH AROUND 600J/KG ELEVATED CAPE FORECAST ACROSS
SOUTHWEST MISSOURI AND SOUTHEAST KANSAS. WILL CONTINUE TO MENTION
THUNDERSTORMS IN THE FORECAST AND HWO. WE CONTINUE TO STAY ON THE
WARM SIDE OF THE LOW THROUGH THE EVENING HOURS INTO THURSDAY
MORNING WITH PWATS ON THE FORECAST SOUNDINGS APPROACHING 1 INCH.
SOME DIFFERENCES IN MODELS ON WHERE HEAVIEST RAINFALL IS GOING TO
OCCUR...BUT FOR THE MOST PART...IT LOOKS LIKE THE SOUTHEASTERN
HALF OF THE CWA WILL SEE THE MOST WEDNESDAY NIGHT INTO THURSDAY.
WRF MODEL SHOWS THE WESTERN HALF OF THE CWA GETTING DRY SLOTTED
WITH ONLY MEAGER AMOUNTS OF RAINFALL WEDNESDAY EVENING INTO
THURSDAY. BEING THREE DAYS OUT AND WITH THE WRF SHOWING THIS DRY
SLOTTING...HAVE DECIDED TO HOLD OFF ON ANY FLOOD WATCH FOR NOW AND
LET THE DAY SHIFT TAKE A LOOK AT ANOTHER MODEL RUN BEFORE PULLING
THE TRIGGER ON ANY WATCH.

SURFACE LOW TRACKS ACROSS SOUTHERN MISSOURI THURSDAY AFTERNOON
WITH COLDER AIR BEHIND THE FRONT THURSDAY AFTERNOON AND EVENING.
THERMAL PROFILES SHOW A COMPLETE CHANGE OVER TO SNOW BY FRIDAY
00Z. COULD SEE SOME ACCUMULATIONS OF SNOW FRIDAY MORNING...OUR
NORTHERN COUNTIES LOOK TO BE THE FAVORED AREAS FOR ACCUMULATING
SNOWS. AFTER LOW MOVES THROUGH...COLD AIR LOOKS TO STAY IN PLACE
THROUGH THE WEEKEND. A SECOND SYSTEM BEING SHOWN ON THE GFS AND
ECMWF FOR THE TUESDAY TIMEFRAME NEXT WEEK. WITH COLD AIR IN PLACE
A GULF MOISTURE BEING PULLED NORTH AHEAD OF THIS LOW...COULD SEE A
SIGNIFICANT WINTER WEATHER EVENT SETTING UP.

CLAYCOMB

&&

.AVIATION...

A GRADUAL DETERIORATION OF FLIGHT CONDITIONS WILL OCCUR OVER THE
NEXT 24 HOURS A STORM SYSTEM ORGANIZES TO THE WEST AND SOUTHERLY
WINDS INCREASE. LOW LEVEL MOISTURE WILL BE ON THE INCREASE WITH
MVFR CEILINGS DEVELOPING LATER TODAY AND TONIGHT. SHOWERS WILL
BEGIN DEVELOPING TONIGHT AND BECOME WIDESPREAD WEDNESDAY. IFR
CONDITIONS WILL DEVELOP WEDNESDAY. LOW LEVEL WIND SHEAR WILL
LINGER THIS MORNING AND DEVELOP AGAIN TONIGHT.

FOSTER

&&

.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&

$$