Wednesday, May 26, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 260816
AFDSGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
316 AM CDT WED MAY 26 2010

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...

CALM WINDS AND MOIST LOW LEVELS WILL LEAD TO LIGHT FOG DEVELOPMENT
LATER TONIGHT. CURRENT THINKING IS MVFR VISIBILITIES WILL BE
PREDOMINANT AS HIGH CLOUDS WILL TEND TO MITIGATE DENSE FOG
THREAT. DID INCLUDE A TEMPO IFR GROUP AT KBBG WHERE
TEMPERATURE/DEW POINT SPREAD IS ALREADY NIL. MORE THUNDERSTORMS
ARE EXPECTED TO IMPACT THE REGION ON WEDNESDAY. TIMING ON THESE
MAY BE A BIT EARLIER THAN PREVIOUS DAYS AS ACTIVITY SHIFTS IN FROM
KANSAS AND SPARKS NEW ACTIVITY OVER SOUTHWEST MISSOURI. THINK THE
MID MORNING THROUGH EARLY AFTERNOON TIME FRAME LOOKS LIKE THE BEST
WINDOW OF OPPORTUNITY. MVFR AND LOCAL IFR CONDITIONS CAN BE
EXPECTED AROUND STORMS. INCLUDED CB IN PREVAILING FOR NOW UNTIL
TIMING AND PLACEMENT CAN BE BETTER DEFINED.

SCHAUMANN

&&

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

$$


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