Wednesday, May 26, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 261726
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1226 PM CDT WED MAY 26 2010

..UPDATE TO AVIATION...

DISCUSSION...

NOT TOO MANY CHANGES TO THE OVERALL FORECAST. MAIN CONCERNS WILL
BE THUNDERSTORMS OVER THE NEXT COUPLE OF DAYS...THEN AGAIN EARLY
NEXT WEEK.

IN THE VERY NEAR TERM...AREAS OF DENSE FOG ARE A CONCERN. ABUNDANT
LOW LEVEL MOISTURE...WEAK SFC WINDS...AND AT LEAST PATCHES OF
CLEAR SKY HAVE ALLOWED SOME FOG TO DEVELOP. KAIZ AND KJLN HAVE
ALREADY DROPPED BELOW 3 MILES...AND A FEW SITES JUST OUTSIDE THE
CWFA INDICATE SOME DENSE FOG. FOR NOW...ALREADY HAVE A MENTION IN
A SHORT TERM FORECAST AND WILL ADD TO THE HWO SHORTLY.

PULSE THUNDERSTORMS DEVELOPED LATE TUE MORNING...WITH INITIATION
FAVORING ANY LEFT OVER CONVECTIVE BOUNDARIES. BELIEVE WE WILL SEE
MUCH OF THE SAME STORY TODAY. PROGGED MLCAPES FROM THE SREF ARE IN
THE NEIGHBORHOOD OF 2000 J/KG BY LATE MORNING/NOONTIME. AT THAT
POINT...TSTMS SHOULD START TO FIRE ALONG LOW LEVEL CONVECTIVE
REMNANT BOUNDARIES OR WITH SUBTLE MID LEVEL FEATURES. SOME HIGH
RES MODELS ARE EMPHASIZING A LEFT OVER BOUNDARY FROM WEAKENING
CONVECTION NOW OVER CNTRL KS AS BEING A POSSIBLE SOURCE OF
INITIATION. ALL IN ALL HAVE HIGH CHC POPS LATE MORNING UNTIL EARLY
EVENING. ISOLATED SEVERE PULSE STORMS ARE AGAIN POSSIBLE WITH
LOCALIZED HEAVY RAIN POTENTIAL WHERE CLUSTERS OF UPDRAFTS PERSIST.

THE UPPER RIDGE WHICH IS PROGGED TO REMAIN OVERHEAD TODAY IS
EXPECTED TO RETROGRADE BACK TO THE WEST OVER THE CNTRL PLAINS FOR
THU/FRI. SFC HIGH PRESSURE WILL NOSE SOUTH INTO MO/EASTERN KS BY FRI
WITH A DRIER AIR MASS SPREADING INTO MUCH OF THE REGION. WE SHOULD
SEE ONE MORE DAY OF DIURNAL TSTMS THU AHEAD OF THE APPROACHING SFC
PRESSURE RISES.

FOR FRI...CAN'T RULE OUT SOME DIURNAL CONVECTION ALONG THE SOUTHERN
MO BORDER...BUT OVERALL COVERAGE SHOULD BE LIMITED...SHOULD
IT OCCUR AT ALL.

SAT/SUNDAY/MON...THE EARLY PORTION OF THE HOLIDAY WEEKEND SHOULD BE DRY AND
WARM WITH HIGH PRESSURE REMAINING IN CONTROL. THE UPPER RIDGE WILL
SHIFT BACK EAST OVER THE REGION SAT WITH A SHORTWAVE MOVING INTO
THE ROCKIES. BY SUNDAY...SOME DIFFERENCES EXIST WITH THE GFS AND
ECMWF IN TERMS OF HOW FAST THE UPPER RIDGE WEAKENS AND PUSHES
EAST TO BE REPLACED BY ZONAL FLOW AND AN APPROACHING FRONT. THE
GFS IS STILL SOMEWHAT FASTER WITH THIS PROCESS...BUT IN GENERAL IT
LOOKS LIKE THERE WILL BE A MODEST INCREASE FOR CHANCES OF
RAIN/TSTMS BY MON/MEMORIAL DAY AS THE TAIL END OF A WEAKENING
FRONT SHIFTS INTO THE CWFA. DSA

&&

AVIATION...

THE PRIMARY AVIATION FORECAST CHALLENGES FOR THE NEXT 24 HOURS
WILL BE ISOLATED THUNDERSTORMS THIS AFTERNOON AND POSSIBLE
VISIBILITY RESTRICTIONS OVERNIGHT. ALTHOUGH CONVECTION HAS
INITIATED OVER THE EASTERN OZARKS... THE OVERALL ENVIRONMENT OVER
THE AERODROMES IS NOT OVERLY FAVORABLE FOR SIGNIFICANT
THUNDERSTORM DEVELOPMENT. A FEW WIDELY ISOLATED STORMS MAY
INITIATE ALONG THE OZARK PLATEAU...BUT WILL BE VERY SHORT LIVED.
A DRYING NORTHERLY FLOW WILL PERSIST THROUGH THE EVENING. THIS
DRYING AND THE LACK OF WIDESPREAD RAINFALL TODAY WILL LIMIT
AVAILABLE MOISTURE AND THE CHANCES OF WIDESPREAD FOG OVERNIGHT.
MINOR RESTRICTIONS TO VISIBILITY WILL BE POSSIBLE FOR JOPLIN AND
SPRINGFIELD. BRANSON WILL HAVE A MORE SIGNIFICANT CHANCE FOR FOG
AS THE AREA WILL SEE LIGHTER WINDS HAVE MORE LOCAL MOISTURE
AVAILABLE FROM THE NEARBY LAKES.

KARDELL

&&

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

$$

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