FXUS63 KSGF 090937
AFDSGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
337 AM CST WED DEC 9 2009

.DISCUSSION...

A POWERFUL WINTER STORM CONTINUES TO PULL AWAY FROM THE MISSOURI
OZARKS EARLY THIS MORNING. WHILE THE OZARKS HAVE BEEN SPARED FROM
THE WORST OF THIS STORM...THERE ARE STILL SOME NOTABLE IMPACTS.
WIND WILL BE THE MAIN CONCERN AS PRESSURES RAPIDLY RISE BEHIND THE
DEPARTING LOW AND A PASSING COLD FRONT. WITH AN ARCTIC AIRMASS
FILTERING INTO THE REGION...WIND CHILLS ARE ALSO A CONCERN. MUCH
QUIETER WEATHER IS THEN ANTICIPATED STARTING TONIGHT.

CURRENTLY...SURFACE LOW PRESSURE IS ANALYZED OVER NORTHERN
ILLINOIS. CENTRAL PRESSURE ON THIS LOW HAS NOW DIPPED TO AROUND
988 MB. A STRONG COLD FRONT TRAILS THE LOW AND IS CURRENTLY
PUSHING ACROSS THE OZARKS. TEMPERATURES AHEAD OF THE FRONT ARE IN
THE UPPER 30S AND LOWER 40S...WHILE TEMPERATURES HAVE PLUMMETED
INTO THE UPPER TEENS AND LOWER TWENTIES ACROSS WESTERN MISSOURI.
PRESSURE GRADIENTS BEHIND THE LOW ARE QUITE IMPRESSIVE...AND
SUPPORTIVE OF STRONG WEST TO NORTHWEST WINDS. A WELL MIXED LOWER
ATMOSPHERE AND STRONG MOMENTUMS JUST OFF THE SURFACE ARE ALSO
SUPPORTING STRONG GUSTS. FINALLY...SURFACE OBSERVATIONS AND RADAR
DATA INDICATE AREAS OF VERY LIGHT SNOW OR FLURRIES.

THE MAIN CONCERN OVER THE NEXT 6 TO 9 HOURS WILL BE THE WIND. THE
TIGHTEST PRESSURE GRADIENTS WILL PERSIST UNTIL AROUND SUNRISE AND
THEN BEGIN TO SLOWLY RELAX. MEANWHILE...THERE IS LIKELY SOME
ISALLOBARIC ACCELERATION AS AN AREA OF STRONG PRESSURE RISES
CONTINUES TO OVERSPREAD THE OZARKS. WE WILL ALSO REMAIN MIXED INTO
THIS MORNING WITH 40 KNOT PLUS MOMENTUMS AROUND 900 MB ALONG AND
NORTH OF THE PLATEAU. WILL THEREFORE LET THE WIND ADVISORY RIDE
INTO THIS MORNING. WINDS WILL SLOWLY DIMINISH THIS AFTERNOON AS
PRESSURE GRADIENTS RELAX.

MEANWHILE...TEMPERATURES WILL CONTINUE TO FALL INTO AT LEAST MID
MORNING AS STRONG COLD AIR ADVECTION CONTINUES. CASE IN
POINT...TEMPERATURES ACROSS WESTERN KANSAS AND NEBRASKA ARE IN THE
-5 TO 5 DEGREE RANGE. WE MAY SEE SOME CLEARING THIS AFTERNOON
WHICH MAY ALLOW FOR A FEW DEGREES OF WARMING. FINALLY...WE ARE
SEEING SOME LOW LEVEL MOISTURE WRAP AROUND THAT DEPARTING LOW. IR
CLOUD TOP TEMPERATURES ARE SUPPORTIVE OF VERY LIGHT SNOW OR
FLURRIES. RECENT OBS AND CALLS INDICATE THIS IS INDEED
OCCURRING...SO WILL KEEP MENTION IN FORECAST THROUGH THIS MORNING.

TONIGHT THEN LOOKS QUITE COLD AS SURFACE HIGH PRESSURE SETTLES
SOUTH ACROSS EASTERN KANSAS AND OKLAHOMA. THE COLDEST TEMPERATURES
MAY ACTUALLY BE ACROSS EASTERN KANSAS AND WESTERN MISSOURI CLOSER
TO THAT SURFACE HIGH. PRESSURE GRADIENTS AND CORRESPONDING WINDS
ACROSS CENTRAL MISSOURI MAY KEEP TEMPERATURES A FEW DEGREES
WARMER. NEVERTHELESS...SINGLE DIGITS LOOK FEASIBLE OVER MOST
AREAS. ALTHOUGH WINDS WILL BE LIGHTER THAN THOSE OF TODAY...WIND
CHILLS WILL STILL DIP TO OR SLIGHTLY BELOW ZERO.

LONG WAVE CHARTS THEN INDICATE A FLAT UPPER LEVEL FLOW ACROSS THE
CENTRAL UNITED STATES INTO EARLY NEXT WEEK. MEDIUM RANGE MODELS DO
INDICATE SOME WEAK RIPPLES IN THE UPPER LEVEL FLOW MIGRATING
ACROSS THE SOUTHERN UNITED STATES. LIMITED MOISTURE AND LOW
AMPLITUDE TO THE ENERGY DICTATE LOW POPS AT BEST. WILL KEEP
THINGS DRY THROUGH THE WEEKEND. TEMPERATURES WILL TEND TO WARM UP
THROUGH THE PERIOD...ALTHOUGH SHORT RANGE MODELS SEEM A BIT TOO
QUICK TO PULL THE COLD AIR OUT OF HERE. WENT WITH THE SLOWER NAM
SOLUTION WITH REGARDS TO THIS.

SCHAUMANN

&&

.AVIATION...

FOR THE 06Z TAF PACKAGE...AN EARLIER FORECAST UPDATE BY THIS
FORECASTER WAS A TAD TOO OPTIMISTIC WITH STRATUS BEHAVIOR FOR THE
REST OF TONIGHT. CYCLONIC FLOW AROUND THE DEPARTING SFC LOW AND
UPSLOPE COMPONENT OF THE WIND AS IT ENCOUNTERS THE PLATEAU WILL
MAINTAIN MVFR CIGS FOR THE REST OF TONIGHT...WITH LIFTING/THINNING
EXPECTED EARLY WEDNESDAY AFTERNOON. OTHERWISE...THE PRIMARY
WEATHER HAZARD FOR AREA TAFS WILL BE THE VERY GUSTY WINDS. THESE
WINDS WILL RELAX BY WEDNESDAY EVENING AS HIGH PRESSURE BUILDS INTO
THE AREA. VFR IS EXPECTED BY MID AFTERNOON WEDNESDAY ONWARD.

GAGAN

&&

.SGF WATCHES/WARNINGS/ADVISORIES...
MO...WIND ADVISORY UNTIL NOON CST TODAY FOR MOZ055>058-066>071-
     077>083-088>092-094.

KS...WIND ADVISORY UNTIL NOON CST TODAY FOR KSZ073-097-101.

&&

$$