FXUS63 KSGF 050026
AFDSGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
626 PM CST THU DEC 4 2008

...UPDATE TO AVIATION...

.DISCUSSION...

SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...

THE LONG WAVE PATTERN WILL CONTINUE TO FEATURE A NORTHWEST FLOW
ALOFT ACROSS THE CENTRAL UNITED STATES. WE WILL CONTINUE TO SEE
SHORT WAVE ENERGY DIVE SOUTHEAST ACROSS THE AREA ALONG WITH
ASSOCIATED SURFACE COLD FRONTAL PASSAGES. LOW LEVEL MOISTURE WILL
PRETTY MUCH BE NIL...BUT WE WILL HAVE TO DEAL WITH PERIODIC BOUTS
OF MID AND UPPER LEVEL MOISTURE. THUS TEMPERATURES WERE THE MAIN
FORECAST CONCERN.

TONIGHT...SURFACE HIGH PRESSURE WILL DRIFT SOUTHEAST INTO THE
AREA. MEANWHILE...AN UPPER LEVEL SHORT WAVE TROUGH WILL APPROACH
THE AREA FROM THE NORTHWEST LATE TONIGHT. SATELLITE IMAGERY
ALREADY INDICATES PLENTY OF MID AND HIGH CLOUDINESS OUT TO OUR
WEST. WITH THE WAVE MOVING IN LATE...THINK WE WILL SEE QUITE A BIT
OF CLOUD COVER TONIGHT. THIS WILL KEEP TEMPERATURES FROM TANKING
OVER MOST AREAS. GENERALLY WENT IN THE LOWER 20S OVER MOST OF THE
AREA. ANY AREAS THAT CAN SEE A FEW HOURS OF CLEAR SKIES WILL HAVE
NO PROBLEM PLUMMETING INTO THE TEENS.

FRIDAY...THAT UPPER LEVEL WAVE WILL QUICKLY SHUNT SOUTHEAST OF THE
OZARKS. AT THE SURFACE...THAT HIGH PRESSURE WILL ALSO SLIDE SOUTH
INTO THE RED RIVER REGION. ALTHOUGH WINDS WILL TURN AROUND TO THE
SOUTH AND SOUTHWEST THROUGHOUT THE DAY...NOT EXPECTING MUCH IN THE
WAY OF WARM ADVECTION. WE MAY ALSO STILL HAVE TO DEAL WITH SOME
MID CLOUDS...ESPECIALLY OVER SOUTHERN MISSOURI. THEREFORE WENT ON
THE COOL SIDE WITH HIGH TEMPERATURES...WITH MOST AREAS IN THE MID
AND UPPER 30S. MAY SEE A FEW LOW 40S OUT TOWARDS HIGHWAY 71.

FRIDAY NIGHT THROUGH SATURDAY NIGHT...ANOTHER SHORT WAVE TROUGH
WILL TRACK ACROSS THE CENTRAL UNITED STATES. THIS WILL DRIVE YET
ANOTHER COLD FRONT THROUGH THE AREA SATURDAY MORNING. WE WILL SEE
ANOTHER INCREASE IN MID AND HIGH CLOUDS FRIDAY NIGHT AND SATURDAY
MORNING. THINK THE BEST LOW LEVEL MOISTURE WILL REMAIN NORTHEAST
OF THE AREA...SO NOT EXPECTING ANY ORGANIZED PRECIPITATION.
SATURDAY NIGHT COULD BE ANOTHER CHILLY ONE...BUT WE MAY AGAIN SEE
AN INCREASE IN CLOUDS WHICH WOULD KEEP THOSE TEMPERATURES FROM
TANKING.

SCHAUMANN

LONG TERM (SUNDAY THROUGH THURSDAY)...

WINDS RETURN TO THE SOUTH BY SUNDAY AFTERNOON AS HIGH PRESSURE
CENTERED OVER THE UPPER MISSISSIPPI VALLEY SHIFTS EASTWARD INTO
THE OHIO RIVER VALLEY. WE MAY SEE A SLIGHT WARMUP ON
MONDAY...HOWEVER INCREASING CLOUD COVER MAY CANCEL OUT THE EFFECT
OF WARMER SOUTH WINDS. FOR NOW WE WILL KEEP MAX TEMPERATURES IN
THE 40S ON MONDAY.

WILL CONTINUE PRECIPITATION CHANCES ON MONDAY AND TUESDAY AS A
COLD FRONT AND DEEPENING UPPER TROUGH MOVE ACROSS THE REGION. AS
FAR AS PRECIPITATION TYPE...WILL CARRY A RAIN/SNOW MIX BEGINNING
MONDAY NIGHT OVER ALONG AND NORTH OF A PITTSBURG KANSAS TO
CAMDENTON TO SALEM LINE...AND GRADUALLY SPREAD THE LINE
SOUTHEASTWARD ACROSS MOST OF THE FORECAST AREA TUESDAY AFTERNOON
AS STRONG LOW LEVEL COLD AIR ADVECTION DEVELOPS BEHIND THE FRONT.
PRECIPITATION SHOULD END TUESDAY EVENING WITH THE PASSAGE OF THE
700 MB TROUGH AXIS. THIS FAR OUT...IT IS HARD TO TELL EXACTLY
WHICH TYPE OF PRECIP WILL DEVELOP...HOWEVER BASED ON GFS FORECAST
SOUNDINGS...LOOKS LIKE IT SHOULD BE A FAIRLY QUICK TRANSITION FROM
RAIN TO SNOW.

GOING INTO WEDNESDAY AND THURSDAY...WILL FAVOR THE ECMWF WHICH
BRINGS A SECONDARY FRONT INTO THE AREA WEDNESDAY NIGHT AND
REINFORCEMENT OF THE COLD CANADIAN AIR WITH A LARGE UPPER TROUGH
DOMINATING MUCH OF THE CONUS.

TERRY


&&

.AVIATION...

FOR THE 0000 UTC KSGF/KJLN TAFS...HIGH PRESSURE OVER THE CENTRAL
PLAINS WILL BUILD SOUTH INTO MISSOURI TONIGHT...THEN BEGIN TO PUSH
SOUTH AND SOUTHEAST OF THE AREA ON FRI. AN UPPER LEVEL DISTURBANCE
WILL PRODUCE SOME EXTENSIVE MID LEVEL CLOUDS/VFR CEILINGS THROUGH TONIGHT
BUT LITTLE ELSE. DSA

&&

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

$$




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