Monday, July 26, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 262336
NATIONAL WEATHER SERVICE SPRINGFIELD MO
636 PM CDT MON JUL 26 2010

..UPDATE TO AVIATION...

DISCUSSION...

..MESOSCALE CONVECTIVE DISCUSSION FOR THIS AFTERNOON...
/ISSUED 1239 PM CDT/

SHOWERS AND THUNDERSTORMS ARE ANTICIPATED TO DEVELOP AND INCREASE
IN COVERAGE THIS AFTERNOON AS TEMPERATURES CLIMB ABOVE CONVECTIVE
TEMPERATURES BASED ON THE 12Z SGF SOUNDING. THE STORMS WILL BE
TAKING ADVANTAGE OF 3000-4000J/KG OF MLCAPE WITH LITTLE IN THE WAY OF
A CAP. MAIN MODE FOR CONVECTION SHOULD REMAIN PULSE TYPE STORMS AS
THERE IS REALLY NO SHEAR TO WORK WITH. SOME STORMS MAY BECOME
STRONG WITH AN ISOLATED CHANCE OF A SEVERE STORM. THE MAIN THREATS
WITH ANY SEVERE PULSE STORMS WOULD BE WIND GUSTS TO 60MPH AND VERY
HEAVY RAINFALL. WITH A FREEZING LEVEL AROUND 15KFT...THE CHANCE
OF LARGE HAIL IS SMALL BUT UP TO QUARTERS WOULD BE POSSIBLE WITH
THE STRONGEST UPDRAFTS. HEAVY RAINFALL...WITH THE POTENTIAL OF
LOCALIZED FLASH FLOODING...WILL BE POSSIBLE AS PWATS AROUND 2
INCHES AND VERY SLOW STORM MOTION WOULD ALLOW RAIN TO FALL OVER
THE SAME LOCATION.

HATCH

..DISCUSSION FOR TONIGHT THROUGH NEXT MONDAY....
/ISSUED 155 PM CDT/

FORECAST FOCUS REMAINS ON NEAR-DAILY CONVECTION CHANCES THROUGH THE
MIDDLE PART OF THE WEEK...BEFORE ATTENTION TURNS TO SOMEWHAT BETTER
RAIN CHANCES AS A WEAK FRONTAL BOUNDARY SETTLES INTO THE
AREA.

OUT OF THE GATE THIS AFTERNOON...THUNDERSTORMS HAVE CONTINUED TO
DEVELOP THIS AFTERNOON ACROSS MUCH OF THE CWA...WITH THE HIGHEST
COVERAGE THUS FAR GENERALLY NORTH OF I-44 AND EAST OF U.S. 65.
STORM COVERAGE AND INTENSITY SHOULD WANE A BIT AROUND AND AFTER
SUNSET THIS EVENING AS BOUNDARY LAYER COOLING ZAPS THE AVAILABLE
CAPE. WITH A VERY TROPICAL AIRMASS IN PLACE PER 2.02 INCH PWAT ON
12Z SGF RAOB...TRENDED TOWARD THE WARM SIDE OF GUIDANCE WITH
OVERNIGHT LOWS...WITH TEMPS GENERALLY IN THE MID 70S.

WITH NO APPRECIABLE CHANGE IN THE SURFACE OR UPPER LEVEL PATTERN
OVER THE NEXT 24-48 HOURS...TUESDAY AND WEDNESDAY LOOK TO BE NEAR
CARBON COPIES OF TODAY. DIURNALLY DRIVEN THUNDERSTORM CHANCES WILL
ONCE AGAIN DEVELOP DURING THE LATE MORNING/EARLY AFTERNOON AS THE
BOUNDARY LAYER DESTABILIZES...AND CONVECTION SHOULD BEGIN TO
DISSIPATE EACH EVENING AROUND SUNDOWN. AT THIS POINT...REALLY DON'T
ANTICIPATE ANY SIGNIFICANT SEVERE WEATHER THREAT TUESDAY OR WEDNESDAY
AS BULK SHEAR VECTORS WILL LARGELY REMAIN BELOW 10 KTS...BUT MUCH
LIKE TODAY...HEAVY RAIN...LIGHTNING...AND PERHAPS SOME SMALL HAIL
WILL BE POSSIBLE WITH THE STRONGEST CONVECTION. AFTERNOON HIGHS
EACH DAY SHOULD TOP OUT BETWEEN ABOUT 90 AND 95 AND OVERNIGHT LOWS
WILL BE IN THE MID 70S. WITH TROPICAL DEWPOINTS IN PLACE...EXPECT
PEAK HEAT INDICES TO BE IN THE UPPER 90S OR LOW 100S AT MANY
LOCATIONS.

WEDNESDAY NIGHT AND INTO THURSDAY...STRONG SHORTWAVE CURRENTLY
EVIDENT ON WATER VAPOR IMAGERY OVER WESTERN ALBERTA WILL DIVE SOUTH
OVER THE UPPER GREAT LAKES. HEIGHT FALLS AHEAD OF THIS FEATURE WILL
ACT TO DAMPEN THE RIDGE AND TURN UPPER FLOW A BIT MORE WESTERLY. AS
THIS TAKES PLACE...EXPECT A WEAK FRONTAL BOUNDARY TO DRIFT SOUTH
ACROSS NORTHERN MISSOURI WEDNESDAY NIGHT...BEFORE BECOMING ORIENTED
NORTHWEST TO SOUTHEAST AND STALLING OUT DURING THE DAY THURSDAY. BIG
QUESTION...AS IT SEEMS TO ALWAYS BE THIS TIME OF YEAR...IS JUST HOW
FAR SOUTH AND WEST THIS FRONT WILL MAKE IT BEFORE STALLING. RIGHT
NOW...NAM/SREF/ECMWF TAKE THE SURFACE FRONT TO ROUGHLY A WARSAW TO
WEST PLAINS LINE BY THURSDAY AFTERNOON...WITH THE UNUSUALLY
CONSERVATIVE GFS KEEPING IT 50-100 MILES FARTHER EAST. AT THIS
POINT...HAVE TRENDED TOWARD THE MORE EASTERLY SOLUTION...OWNING TO
CLIMATOLOGY AND DOUBTS ABOUT JUST HOW MUCH THE RIDGE CAN BE
SQUASHED. AS A RESULT OF THIS UNCERTAINTY...HAVE GENERALLY BROAD
BRUSHED POPS THURSDAY AND FRIDAY...WITH HIGHER CHANCES CLOSER TO THE
FRONT. WITH NORTHWEST FLOW IN PLACE AND A BOUNDARY IN THE
AREA...CERTAINLY COULDN'T RULE OUT SOME MCS ACTIVITY IN THE
REGION...ESPECIALLY FRIDAY NIGHT...BUT DIDN'T MAKE ANY ATTEMPT TO
GET CUTE WITH POPS 5 DAYS OUT.

HEADING INTO THE WEEKEND...MODEL GUIDANCE IS IN REASONABLE AGREEMENT
IN AN EVENTUAL RETURN TO MORE ZONAL UPPER FLOW...WITH WHAT IS LEFT
OF THE FRONT MIXING BACK NORTH LATE IN THE WEEKEND OR EARLY NEXT
WEEK. THIS SHOULD RESULT IN A RETURN TO NORMAL TO ABOVE NORMAL TEMPS
HEADING INTO NEXT WEEK.

BOXELL

&&

AVIATION...
/ISSUED 633 PM CDT MON JUL 26 2010/

FOR THE 27/0000Z KSGF/KJLN/KBBG TAFS...SCATTERED THUNDERSTORMS
WILL GRADUALLY DIMINISH THIS EVENING...OTHERWISE EXPECT VFR
CONDITIONS FOR MUCH OF THE TAF PERIOD. SCATTERED STORMS ARE
EXPECTED TO REDEVELOP AGAIN LATE IN THE TAF PERIOD. DSA

&&

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

$$

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