Sunday, May 30, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 301723
AFDSGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1223 PM CDT SUN MAY 30 2010

..UPDATE TO AVIATION...

UPDATE...
ISOLATED CONVECTION WAS FORMING AT MIDDAY WITHIN A MOIST UNCAPPED
ENVIRONMENT. THE ACTIVITY WAS BEING SUPPORTED BY A MOISTURE PLUME
THAT HAS ADVECTED INTO THE REGION AROUND AN UPPER LOW OVER
MISSISSIPPI. A VORTICITY LOBE EXTENDED NORTHWEST INTO SOUTHERN
MISSOURI. EXPECT ISOLATED TO SCATTERED CONVECTION AREA WIDE THIS
AFTERNOON AND EVENING WITH THE ACTIVITY MOST NUMEROUS ALONG AND
EAST OF HIGHWAY 13. THERE IS ONLY A LIMITED RISK FOR SEVERE STORMS
AT BEST AS LAPSE RATES ARE VERY WEAK AND VIRTUALLY NO SHEAR IS IN
PLACE. LOCALLY RAINFALL AND FREQUENT LIGHTNING WILL BE THE PRIMARY
RISKS. CONVECTION WILL ALSO DEVELOP ALONG A FRONT IN CENTRAL
KANSAS. THIS ACTIVITY MAY IMPACT LOCATIONS NEAR THE MISSOURI
KANSAS BORDER LATER THIS AFTERNOON AND TONIGHT. OTHER THAN
INCREASING THE CHANCE OF PRECIPITATION ACROSS SOUTHERN
MISSOURI...LITTLE CHANGE MADE TO THE FORECAST AT THIS TIME.

FOSTER

&&

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...

FOR THE 1800Z TAFS...A BROAD WEAK UPPER LEVEL LOW CENTERED OVER
MISSISSIPPI WITH ITS TROUGH AXIS EXTENDING NORTHWEST INTO
MISSOURI WILL SLOWLY FILL WHILE LIFTING OUT TO THE NORTHEAST AND
DISSIPATING. THIS SYSTEM HAS BROUGHT SIGNIFICANT LOW AND MID LEVEL
MOISTURE TO THE OZARKS REGION...SETTING THE STAGE FOR SCATTERED
CONVECTIVE ACTIVITY TODAY AND THIS EVENING. EXPECT A SOMEWHAT
GREATER CHANCE OF THUNDERSTORM ACTIVITY IN THE VICINITY OF KSGF
AND AREAS EAST AS MOISTURE IS SLIGHTLY MORE ABUNDANT. A WEAKENING
COLD FRONT EXTENDING FROM NORTHEASTERN KANSAS SSW TOWARD WICHITA
WILL CONTINUE TO MOVE SLOWLY EASTWARD INTO EASTERN KANSAS/WESTERN
MISSOURI BY TOMORROW MORNING. THIS WILL BRING A SECOND SHOT OF RAIN
SHOWER ACTIVITY INTO OUR WESTERN FORECAST AREA LATER TOMORROW
MORNING. INCLUDED EARLY MORNING GROUND FOG IN THE TAFS WITH
VISIBILITIES MVFR AS LOW LEVEL MOISTURE WILL PERSIST IN NEAR CALM
WINDS.

FOSTER/COLUCCI

&&

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

$$


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