FXUS63 KSGF 270153
AFDSGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
753 PM CST THU NOV 26 2009

.UPDATE...

TEMPERATURES EARLY THIS EVENING ARE PLUMMETING GIVEN THE CLEAR
SKIES...LIGHT WINDS..AND DRY AIRMASS. SOME LOCATIONS ALONG AND
WEST OF HIGHWAY 65 ARE ALREADY APPROACHING PREVIOUSLY FORECASTED
LOWS. HAVE BUMPED DOWN EXPECTED LOWS A CATEGORY OVER MOST
LOCATIONS. AREAS WEST AND NORTH OF THE OZARK PLATEAU SHOULD SEE
TEMPERATURES STEADY OFF LATER THIS EVENING AS A WEAK SURFACE RIDGE
AXIS SLIDES EAST INTO SOUTH CENTRAL MISSOURI. UPDATES ALREADY
SENT.

SCHAUMANN

&&

.DISCUSSION...

MAIN FORECAST FOCUS IN THIS FORECAST PACKAGE DEALS WITH A WARM UP
FRIDAY AND SATURDAY...AS HIGHS RETURN TO THE 60S. THEN ATTENTION
TURNS TO A STORM SYSTEM THAT WILL AFFECT THE REGION LATE THIS
WEEKEND INTO EARLY NEXT WEEK.

SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...

A DEEP UPPER LEVEL TROUGH IS CURRENTLY LOCATED ACROSS THE EASTERN
HALF OF THE CONUS...WHILE A DEEP UPPER LEVEL RIDGE IS LOCATED
ACROSS THE WESTERN CONUS. THIS HAS RESULTED IN COOLER CONDITIONS
ACROSS THE EASTERN CONUS...INCLUDING OUR CWA...WITH WARMER
CONDITIONS ACROSS THE WESTERN CONUS. THESE FEATURES WILL MOVE TO
THE EAST THE REST OF TODAY INTO THE OVERNIGHT HOURS RESULTING IN
THE UPPER LEVEL RIDGE BUILDING INTO THE AREA. SURFACE HIGH
PRESSURE WILL PASS SOUTH OF THE AREA THIS EVENING AND OFF TO THE
SOUTHEAST TONIGHT. THIS WILL RESULT IN A GOOD RADIATIONAL COOLING
SET UP AS DRY SURFACE CONDITIONS...LIGHT WINDS AND CLEAR SKIES
WILL BE THE RULE. THEREFORE...TEMPERATURES SHOULD FALL OFF PRETTY
QUICKLY AFTER SUNSET THIS EVENING. SURFACE WINDS SHOULD BEGIN TO
SHIFT TO THE SOUTHWEST AFTER MIDNIGHT AS THE HIGH PUSHES TO THE
SOUTHEAST OF THE AREA AND WARM AIR ADVECTION SPREADS INTO THE AREA
FROM THE WEST. THIS SHOULD GENERALLY STEADY OFF TEMPERATURES OR
ALLOW THEM TO RISE A BIT OVERNIGHT...ESPECIALLY OUT WEST.

TWO VERY PLEASANT DAYS ARE ON TAP FOR FRIDAY AND SATURDAY AS THE
UPPER LEVEL RIDGE SETS UP OVER THE REGION AS 850 MB TEMPERATURES
WARM INTO THE LOWER TEENS CELSIUS. THIS WILL ALLOW TEMPERATURES TO
REACH INTO LOW TO MIDDLE 60S TOMORROW WEST OF HIGHWAY 65...WITH
UPPER 50S TO LOWER 60S EXPECTED EAST OF HIGHWAY 65. MODELS CONTINUE
TO SHOW A WEAK DISTURBANCE IN THE 500 MB FLOW FOR SATURDAY
AFTERNOON...WHICH MAY LIMIT TEMPERATURES FROM REACHING THEIR FULL
POTENTIAL...AS 925 MB TEMPERATURES FALL A FEW DEGREES BEHIND THIS
FEATURE. NEVERTHELESS A WARM AIRMASS WILL REMAIN OVER THE AREA...
AND HIGHS SHOULD STILL WARM INTO THE 60S AREA WIDE.

WISE

LONG TERM (SUNDAY THROUGH THURSDAY)...MEDIUM RANGE MODELS AND
ENSEMBLES HAVE COME INTO BETTER AGREEMENT FOR THE FIRST HALF THE
EXTENDED PERIOD. A SPLIT FLOW PATTERN WILL CONTINUE INTO EARLY
NEXT WEEK WITH BOTH THE NORTHERN AND SOUTHERN STREAMS REMAINING
ACTIVE. A NORTHERN STREAM WAVE WILL DRIVE A COLD FRONT INTO THE
AREA ON SUNDAY...WHILE SOUTHERN STREAM ENERGY BRIEFLY CUTS OFF
FROM THE FLOW OVER THE DESERT SOUTHWEST. OVERALL...EXPECT THE BEST
CHANCES FOR RAIN SUN/SUN NIGHT WITH TEMPERATURES FALLING TO AT OR
BELOW AVERAGE NEXT WEEK.

SOME SEMBLANCE OF UNCERTAINTY REMAINS FROM MIDWEEK ONWARD AS EACH 
MODEL HANDLES THE BEHAVIOR OF THE REMNANT CUT OFF LOW OVER THE 
SOUTHWEST DIFFERENTLY. BLURRING ONES EYES...EXPECTATIONS ARE FOR 
THIS WAVE TO CUT ACROSS THE SOUTHERN TIER OF STATES WITH THE VAST 
BULK OF THE ASSOCIATED SENSIBLE WEATHER AFFECTS REMAINING TO OUR 
SOUTH. INDICATIONS CONTINUE THAT A SURGE OF COLD AIR IS POSSIBLE 
LATE IN THE WEEK.

GAGAN

&&

.AVIATION...

VFR CONDITIONS ARE EXPECTED ACROSS THE AREA FOR THE NEXT 24 HOURS.
SKIES WILL BE CLEAR WITH WINDS SHIFTING TO SOUTHERLY. WIND GUSTS
WILL INCREASE TOMORROW AFTERNOON AS THE SURFACE PRESSURE GRADIENT
BEGINS TO TIGHTEN.

KARDELL

&&

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

$$