Thursday, May 27, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 270504
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1204 AM CDT THU MAY 27 2010

..UPDATE TO AVIATION...

..MESOSCALE CONVECTIVE DISCUSSION...

UPDATE...

STORMS HAVE DISSIPATED DUE TO LOSS OF DAYTIME HEATING. THERE MAY
BE AN ISOLATED SHRA TO POP UP OVERNIGHT DUE TO A MOIST AND
SOMEWHAT UNSTABLE ATMOSPHERE...BUT THIS WILL BE BY FAR THE
EXCEPTION RATHER THAN THE RULE. WITH LESS AREAS OBSERVING RAINFALL
TODAY...FOG WILL BE MORE PATCHY DURING THE OVERNIGHT HOURS AS
CROSSOVER TEMPS CONTINUE TO BE IN THE LOWER 60S. HWO WILL BE
UPDATED SHORTLY TO REMOVE CONVECTIVE RISKS.

GAGAN

&&

DISCUSSION...

A WARM AND HUMID AIRMASS REMAINED OVER THE REGION WEDNESDAY
UNDERNEATH AN UPPER RIDGE AXIS EXTENDING FROM TEXAS TO THE GREAT
LAKES. CONVECTION THROUGH EARLY AFTERNOON HAS BEE CONFINED ACROSS
THE EASTERN OZARKS INTO SOUTHEAST MISSOURI WHERE DEEP MOISTURE
CONVERGENCE WAS IN PLACE. THE LACK OF SURFACE CONVERGENCE AND
SLIGHTLY DRIER ALOFT SEEMED TO BE THE INHIBITING FACTORS TO
THUNDERSTORM DEVELOPMENT ACROSS THE REMAINDER OF THE MISSOURI
OZARKS AND SOUTHEAST KANSAS.

ISOLATED SHOWERS AND THUNDERSTORMS WILL REMAIN POSSIBLE THROUGH
THE EARLY EVENING WITH THE ACTIVITY MORE FOCUSED FROM SOUTH
CENTRAL INTO SOUTHEAST MISSOURI. PATCHY FOG WILL AGAIN DEVELOP
LATE TONIGHT AND EARLY THURSDAY.

THURSDAY WILL BE SIMILAR TO THE PAST COUPLE OF DAYS. A LINGERING
MOIST AND UNSTABLE AIRMASS WILL AGAIN LEAD TO PRIMARILY DIURNALLY
DRIVEN CONVECTION. A VORTICITY LOBE MAY ROTATE AROUND THE UPPER
RIDGE FROM THE UPPER MIDWEST TOWARD THE OHIO RIVER VALLEY. THIS
MAY ENHANCE THE COVERAGE OF THUNDERSTORMS ACROSS SOUTH CENTRAL
MISSOURI EASTWARD. HOWEVER THE OVERALL LACK OF SIGNIFICANT SYNOPTIC
SCALE LIFT WILL RESULT IN UNORGANIZED CONVECTION AND AN OUTSIDE
RISK FOR SEVERE WEATHER.

SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION LATER THURSDAY
INTO FRIDAY. A DRIER AIRMASS WILL ADVECT INTO THE OZARKS FRIDAY AS
THE SURFACE RIDGE EXTENDS FROM THE GREAT LAKES INTO THE OZARKS.
THIS WILL SHUT OFF CONVECTIVE DEVELOPMENT FOR A COUPLE OF DAYS BUT
HAVE ONLY MODEST IMPACTS ON DAY TIME TEMPERATURES. OVERNIGHT LOWS
WILL BE A BIT COOLER GIVEN THE DRIER AIRMASS.

THE UPPER RIDGE WILL FLATTEN LATE IN THE WEEKEND INTO EARLY NEXT
WEEK AS A SHORTWAVE TROUGH RIDES ACROSS THE NORTHERN TIER OF THE
U.S. THIS MAY CAUSE A WEAK FRONT TO DROP INTO THE AREA FOR
MEMORIAL DAY. ISOLATED CONVECTION MAY DEVELOP AS EARLY SUNDAY AS
MOISTURE INCREASES WITH A BETTER CHANCE ON MEMORIAL DAY. AT THIS
TIME IT APPEARS THE ACTIVITY ON MEMORIAL DAY WILL BE ISOLATED TO
SCATTERED WITH A LIMITED RISK FOR SEVERE WEATHER.

FOSTER

&&

AVIATION...

FOR THE 06Z TAF PACKAGE...NOT AS MUCH RAIN WAS OBSERVED WEDNESDAY
ACROSS THE REGION...AS A RESULT FOG WILL BE MUCH PATCHIER THIS
MORNING. JLN/SGF/BBG MAY FLIRT BRIEFLY WITH MVFR VIS TOWARDS
DAYBREAK...BUT CONFIDENCE IS LOWER THAN COMPARED TO YESTERDAY
MORNING. THURSDAY WILL BE A NEAR CARBON COPY OF WEDNESDAY. LATE
MORNING AND AFTERNOON CU WILL GIVE WAY TO WIDELY SCT SHRA/TSRA
FROM MID AFTERNOON INTO THE EVENING...DISSIPATING AFTER SUNSET.
WINDS WILL BE A BIT VARIABLE...BUT SETTLE ON A NORTHERLY DIRECTION
DURING THE DAYLIGHT HOURS OF THURSDAY

GAGAN

&&

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

$$

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