Thursday, May 27, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 271713
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1213 PM CDT THU MAY 27 2010

UPDATE...

GOING FORECAST GENERALLY ON TRACK THIS MORNING...WITH JUST A FEW
TWEAKS TO SKY COVER...HOURLY TEMPS...AND POPS WITH THIS UPDATE.

HIGH PRESSURE CONTINUES TO OOZE INTO THE AREA FROM THE NORTH THIS
MORNING AS THE UPPER RIDGE AXIS SHIFTS EAST ACROSS THE EASTERN
PLAINS. VERY WEAK SHORTWAVE IS EVIDENT IN WATER VAPOR IMAGERY NEAR
THE CHICAGO AREA...AND THIS WAVE IS EXPECTED TO VERY SLOWLY MOVE
SOUTH ACROSS THE MID OHIO VALLEY OVER THE NEXT 24 HOURS. CU
DEVELOPMENT IN ASSOCIATION WITH THIS WAVE HAS BEEN DECIDEDLY MEAGER
THUS FAR TODAY...BUT ANTICIPATE THINGS TO BUBBLE UP A BIT MORE
THIS AFTERNOON AS SURFACE TEMPS CONTINUE TO CLIMB. MODEL GUIDANCE
CONTINUES TO SPIT OUT SCATTERED DIURNAL THUNDERSTORM DEVELOPMENT
IN LINE WITH THE HAPPENINGS OF THE LAST COUPLE OF DAYS...BUT 12Z
SGF AND TOP RAOBS REVEAL DEEP DRY AIR ALOFT...WHICH WILL LIKELY
ONLY GET DEEPER AND DRYER AS SUBSIDENCE ASSOCIATED WITH THE
AFOREMENTIONED AREA OF HIGH PRESSURE BUILDS SOUTH AND COULD VERY
WELL HINDER SOME OF THE CONVECTIVE DEVELOPMENT ACROSS THE AREA.
THAT BEING SAID...HAVE MAINTAINED CHANCE POPS ACROSS AREAS EAST OF
US 65...AND SLIGHT CHANCE WEST THIS AFTERNOON AND EARLY EVENING. AS HAS
BEEN THE CASE THE LAST FEW DAYS...THERE WILL BE A CONDITIONAL
THREAT OF A FEW LARGE HAIL STONES AND GUSTY WINDS WITH ANY
STRONGER UPDRAFTS THAT ARE ABLE TO DEVELOP.

BOXELL

&&

DISCUSSION...

ISOLATED/WIDELY SCATTERED CONVECTION (AT BEST) AFFECTED THE CWFA
ON WED...AND EXPECT MORE OF THE SAME TODAY. LIKE THE PAST COUPLE
OF DAYS...CAN'T RULE AN ISOLATED STRONG/SEVERE STORM AND VERY
ISOLATED POCKETS OF HVY RAINFALL. LOOKS LIKE IN GENERAL THE
EASTERN CWFA WILL BE FAVORED WHERE SOMEWHAT BETTER MOISTURE
RESIDES. SLIGHTLY BETTER...BUT STILL MEAGER...MID LEVEL WINDS MAY
ALLOW UPDRAFTS TO STAY TOGETHER A LITTLE LONGER...BUT THE OVERALL
SEVERE STORM THREAT WILL BE LOCALIZED WITH PULSE TYPE STORMS.

A STRONG UPPER LEVEL RIDGE HAS RETROGRADED WEST BACK OVER THE
PLAINS...AND SFC HIGH PRESSURE RISES AND A DRIER AIR WILL MOVE
SOUTH INTO THE REGION FOR FRI/SAT. SHOULD BE A NICE START TO THE
HOLIDAY WEEKEND. A SHORTWAVE WILL MOVE AROUND THE UPPER RIDGE...SOUTH
THEN SSW FROM THE GREAT LAKES REGION INTO TN FRI...THEN INTO MS/AL
SAT/SUNDAY. CAN'T RULE OUT SOME ISOLD DIURNAL CONVECTION FOR
PARTS OF THE FAR SOUTHEASTERN CWFA SAT (VERY UNLIKELY GIVEN THE
DRY AIR MASS) AND SUNDAY WITH THIS FEATURE. HAVE SOME SLIGHT POPS
FOR EASTERN CWFA FOR SUNDAY AFTERNOON TO ACCOUNT FOR THIS.
MEANWHILE...A STRONG STORM WILL MOVE INTO THE ROCKIES AND NORTHERN
HIGH PLAINS THIS WEEKEND THEN BEGIN TO SHIFT NORTHEAST....AS THE
DOMINATE UPPER RIDGE THAT HAS BEEN OVER THE CENTRAL CONUS FLATTENS
OUT. THE TRAILING FRONT ASSOCIATED WITH THIS SYSTEM WILL MOVE INTO
THE CNTRL PLAINS 0N SUNDAY...POSSIBLY BRINGING SOME RAIN/TSTM
CHANCES TO THE WESTERN CWFA SUNDAY NIGHT...AND THEN INTO THE REST
OF THE AREA FOR MEMORIAL DAY MON.

BEYOND MON...THE WEAK FRONT MAY HANG UP NEAR OR JUST SOUTH OF THE
AREA ON TUE...AND THE CURRENT FORECAST OF SMALL POPS LOOKS
WARRANTED. OVERALL...THE UPPER PATTERN BECOMES MORE ZONAL OVER THE
NORTHERN CONUS NEXT WEEK AND PICKING OUT OR TIMING ANY SFC
FEATURES LATE IN THE EXTENDED FCST IS DIFFICULT AT BEST. DSA

&&

AVIATION...

18Z TAFS...

AFTERNOON CU HAS ONCE AGAIN DEVELOPED TODAY...WITH CIGS EXPECTED
TO BE IN LOW END VFR/OCCASIONAL MVFR THROUGH THE AFTERNOON.
THUNDERSTORM DEVELOPMENT IS EXPECTED TO BE VERY WIDELY SCATTERED
THIS AFTERNOON...AND HAVE ONLY INDICATED A CB GROUP IN 18Z TAFS AS
CONFIDENCE IS VERY LOW THAT TSRA WILL ACTUALLY BE OBSERVED AT ANY
TERMINAL. THUNDERSTORMS AND ASSOCIATED CIGS ARE EXPECTED TO WANE
WITHIN A FEW HOURS OF SUNSET TONIGHT...WITH SKIES CLEARING BY
MORNING. LIGHT FOG IS A POSSIBILITY EARLY FRIDAY MORNING...WITH
VIS PERHAPS TOUCHING MVFR FOR A TIME NEAR SUNRISE.

WINDS THROUGH THE PERIOD SHOULD REMAIN QUITE LIGHT FROM THE
NORTHEAST DURING THE DAY...AND GOING VRB TO CALM AT NIGHT.

BOXELL

&&

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

$$

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