Sunday, May 30, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 301052
AFDSGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
552 AM CDT SUN MAY 30 2010

..UPDATE TO AVIATION...

DISCUSSION...

THE REGION WILL SEE INCREASING CHANCES OF PRECIPITATION TODAY AND
INTO MEMORIAL DAY AFTER A GREAT START TO THE HOLIDAY WEEKEND. A
WEAK COLD FRONT WILL ATTEMPT TO MAKE ITS WAY INTO THE OZARKS
THIS AFTERNOON IN RESPONSE TO TROUGHING ACROSS THE WESTERN U.S. AS
AN UPPER LEVEL LOW MOVES ACROSS CANADA. IN ADDITION A CUTOFF LOW
REMAINS OVER THE SOUTHEASTERN GULF STATES AND WILL CONTINUE TO
SLOWLY SLIDE WESTWARD AND BE PICKED UP IN THE AFOREMENTIONED
TROUGH. THE COMBINATION OF THE APPROACHING WEAK FRONT AND THE
RETROGRADING UPPER LOW OVER THE SOUTHEAST WILL PROVIDE THE FUEL
FOR SHOWER AND THUNDERSTORM DEVELOPMENT THIS AFTERNOON INTO
MEMORIAL DAY.

LOOKING AT THE SREF/GFS/ECMWF/GEM MODELS...ALL ARE INDICATING THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS THE OZARKS AROUND
THE 18Z TO 21Z TIME FRAME. THIS WOULD CORRESPOND WELL WITH MAXIMUM
DIURNAL HEATING...COOLING ALOFT VIA UPPER LEVEL LOW...INCREASING
LOW LEVEL MOISTURE AND PROGGED SURFACE BASED CAPE VALUES IN THE
1000 TO 1500 J/KG RANGE. WITH THAT SAID...WOULD EXPECT TO SEE MORE
PULSE TYPE TO MULTICELLULAR TYPE THUNDERSTORMS AS SHEAR WILL BE
WEAK AND FORCING WILL BE LIMITED TO ANY OUTFLOW BOUNDARIES AROUND
THOUGH A WEAK UPPER LEVEL WAVE MAY ALSO PROVIDE SOME ADDITIONAL
SUPPORT AS WELL.

THE COLD FRONT IS EXPECTED TO TRY TO MAKE ITS WAY ACROSS THE
REGION SUNDAY NIGHT INTO MONDAY MORNING AND STALL ACROSS THE AREA
WHICH WOULD PROVIDE THE FOCUS FOR ADDITIONAL SHOWERS AND STORMS
MONDAY. THIS LOOKS TO BE THE BETTER PERIOD FOR THE POTENTIAL OF
STRONG TO POSSIBLY SEVERE STORMS AS SOME SHEAR WILL BE AVAILABLE
ALBEIT WEAK IN NATURE AND LOW LEVEL INSTABILITY VIA NAM IS
EXPECTED TO BE AROUND 2000 J/KG IN ADVANCE OF THE FRONT. WILL KEEP
THE POSSIBILITY OF STRONG TO SEVERE THUNDERSTORMS CURRENTLY
MENTIONED IN THE FORECAST AS A RESULT.

THE FORECAST FOR TUESDAY THROUGH THE END OF THE WEEK BECOMES
RATHER A MESS AS THE GFS AND ECMWF CONTINUE TO DIFFER
SIGNIFICANTLY ON THE STRENGTH OF A COLD FRONT THAT MOVES THROUGH
THE REGION TOWARDS THE END OF THE WEAK...AND THE DEVELOPMENT OF
NORTHWEST FLOW ACROSS THE CENTER OF THE COUNTRY NEXT WEEKEND. THE
GFS IS MUCH STRONGER THAN THE ECMWF WITH BOTH FEATURES. AT THIS
POINT...THE LIKELY SOLUTION IS PROBABLY SOMEWHERE IN THE MIDDLE.
JUST HARD TO AGREE WITH THE GFS PUSHING THE COLD FRONT TO THE GULF
STATES AT THIS TIME OF YEAR. ANY WAY I LOOK AT IT...CONFIDENCE IS
FAIRLY LOW WITH REGARD TO THE MODEL OUTPUT PAST THE MIDDLE OF THE
WEEK. WILL NEED TO CONTINUE TO WATCH TRENDS AND HOPEFULLY A
CONSENSUS IN THE MODELS WILL EMERGE IN THE NEXT FEW RUNS.

HATCH

&&

AVIATION...

HIGH END MVFR VISIBILITIES ARE EXPECTED EARLY THIS MORNING AROUND
KSGF AND KBBG DUE TO LIGHT FOG. ISOLATED TO WIDELY SCATTERED
AFTERNOON SHOWERS AND THUNDERSTORMS ARE THEN EXPECTED ALONG AND
EAST OF THE HIGHWAY 65 CORRIDOR. THIS PUTS KSGF AND KBBG ON THE
WESTERN EDGE OF THE EXPECTED ACTIVITY...SO WENT WITH VCSH AND CB
IN PREVAILING GROUPS. CONFIDENCE IS TOO LOW IN PLACEMENT AND
TIMING TO GO WITH TEMPO OR PREVAILING THUNDERSTORM GROUPS AT THIS
TIME. LIGHT FOG WILL THEN BE POSSIBLE AGAIN LATE TONIGHT.
INTRODUCED VISIBILITIES IN THE LOW END VFR RANGE STARTING AT 09Z
AND WILL CONTINUE TO EVALUATE THE POTENTIAL FOR MVFR.

SCHAUMANN

&&

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

$$


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