Tuesday, June 22, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 221917
NATIONAL WEATHER SERVICE SPRINGFIELD MO
217 PM CDT TUE JUN 22 2010

DISCUSSION...
/ISSUED 217 PM CDT TUE JUN 22 2010/

HEAT/HUMIDITY THROUGH WEDNESDAY...AS WELL AS FRONTAL PASSAGE AND
ASSOCIATED POPS...WX...AND TEMPERATURES CONTINUE TO BE THE FOCUS
FOR THE NEXT FEW DAYS.

SHORT TERM (TONIGHT THROUGH FRIDAY MORNING)...

REGION REMAINS SITUATED UNDER AN EXPANSIVE UPPER LEVEL RIDGE...WITH
MAIN BELT OF WESTERLIES WELL NORTH ACROSS THE UPPER MISSISSIPPI
VALLEY AND GREAT LAKES. VERY WARM MID LEVEL TEMPERATURES SAMPLED BY
KSGF AND KOUN 12Z RAOBS ARE KEEPING A LID ON ANY APPRECIABLE CU
DEVELOPMENT THUS FAR THIS AFTERNOON. ANY CLOUD DEVELOPMENT THAT WAS
ABLE TO TAKE PLACE SHOULD DISSIPATE SHORTLY AFTER SUNSET WITH THE
LOSS OF SURFACE HEATING.

WEDNESDAY LOOKS TO BE A NEAR CARBON-COPY OF TODAY...WITH
TEMPERATURES CLIMBING YET AGAIN INTO THE MID 90S. SIMILAR TO
TODAY...ATMOSPHERE SHOULD REMAIN CAPPED...KEEPING SKIES MOSTLY
SUNNY AND POPS NIL. DEWPOINT VALUES ARE EXPECTED TO BE SIMILAR TO
TODAY /UPPER 60S/LOW 70S/...YIELDING HEAT INDICES ONCE AGAIN IN
THE 100-105 RANGE.

HEIGHT FALLS IN ADVANCE OF SHORTWAVE ENERGY TRAVERSING THE GREAT LAKES
WILL ACT TO FLATTEN THE RIDGE AND TURN THE MEAN UPPER FLOW SOMEWHAT
MORE NORTHWESTERLY WEDNESDAY AFTERNOON AND EVENING. AS THIS TAKES
PLACE...A FRONTAL BOUNDARY IS EXPECTED TO SLIP SOUTH TOWARD...AND AT
LIKELY AT LEAST PARTIALLY THROUGH...THE SGF CWA LATE WEDNESDAY NIGHT
AND THURSDAY. OUT AHEAD OF THE FRONT...SHOWERS AND THUNDERSTORMS
WILL LIKELY BE ONGOING WEDNESDAY EVENING JUST NORTH OF THE CWA...AND
BEGINNING TO MOVE INTO THE REGION LATE WEDNESDAY NIGHT/EARLY THURSDAY
MORNING. MODEL GUIDANCE HAS TRENDED TOWARD A SOMEWHAT MORE
AMPLIFIED SOLUTION AS OF LATE...AND GFS...NAM/WRF...AND SREF ARE IN
BROAD AGREEMENT IN BRINGING THE FRONT AS FAR SOUTH AS THE ARKANSAS
BORDER BY THURSDAY...WITH THE EUROPEAN KEEPING IT NORTH TOWARD THE
I-70 CORRIDOR. RIGHT NOW...AM PLAYING RATHER CONSERVATIVE WITH THE
FRONTAL POSITION...AS MY SUSPICION IS THAT MODELS MIGHT BE TAKING
THAT BOUNDARY A BIT TOO FAR SOUTH...AND HAVE ONLY BROUGHT THE FRONT
AS FAR SOUTH AS I-44. AT ANY RATE...SHOWERS AND THUNDERSTORMS WILL
LIKELY BE OCCURRING IN AT LEAST A WIDELY SCATTERED FASHION IN THE
VICINITY OF THE FRONT AS IT STALLS OUT THURSDAY. WITH THE BOUNDARY
IN THE AREA...SEVERE WEATHER CHANCES WEDNESDAY NIGHT AND THURSDAY
CERTAINLY WON'T BE NIL...BUT REALLY DON'T ANTICIPATE ANYTHING TOO
WIDESPREAD. STRONG CONVECTION THURSDAY WOULD LIKELY BE CONFINED TO
ANY AREA THAT IS ABLE TO EXPERIENCE SOME CLEARING AND THUS
STRONGER DIABATIC HEATING DURING THE DAY...BUT WITH STRONGER UPPER
FLOW/BULK SHEAR VALUES WELL NORTH OF THE CWA...CONVECTIVE
ORGANIZATION WILL BE TOUGH TO COME BY.

BOXELL

LONG TERM (FRIDAY THROUGH THURSDAY)...

MED RANGE MODEL OUTPUT IS IN DECENT AGREEMENT THROUGH THE
EXTENDED FORECAST. AN INCREASINGLY AMPLIFIED FLOW IS PROGGED...
WITH PROSPECTS OF A LARGE SCALE OMEGA PATTERN (POTENTIAL BLOCK?)
DEVELOPING OVER NORTH AMERICA HEADING INTO EARLY NEXT WEEK.
OVERALL...EXPECT WARMER THAN AVERAGE CONDITIONS TO CONTINUE. HEAT
INDICES WILL ONCE AGAIN ATTEMPT TO TOP 100F AND REMAIN IN THE
100-105 RANGE FRIDAY INTO SUNDAY. CHANCES FOR RAIN LOOK TO BE
CONFINED TO AFTERNOON/EVENING ISO TO WIDELY SCT SHRA/TSRA FRIDAY
INTO SUNDAY...WITH INCREASING CONFIDENCE IN A FRONTAL PASSAGE
SUNDAY NIGHT/MONDAY AS THE UPPER FLOW AMPLIFIES. IF AN OMEGA BLOCK
CAN INDEED DEVELOP...AS SUGGESTED BY THE LAST FEW RUNS OF THE
ECMWF...THERE IS A RISK TO HAVE TEMPS REMAIN WELL ABOVE AVG NEXT
WEEK.

GAGAN

&&

AVIATION...
/ISSUED 1225 PM CDT TUE JUN 22 2010/

FOR THE 18Z TAF PACKAGE...VFR CONDITIONS ARE EXPECTED FOR THE NEXT
24 HOURS AND LIKELY BEYOND. DIURNAL CU FIELD IS BEGINNING TO
DEVELOP...THOUGH WITH WARMER MID LEVEL TEMPERATURES...THE SPATIAL
EXTENT OF CU WILL BE LOWER VERSUS YESTERDAY. SOUTHWESTERLY WINDS
WILL BE GUSTY AT TIMES THIS AFTERNOON...AND WILL NEED TO KEEP AN
EYE ON LOW LEVEL WIND SHEAR AT JLN LATE TONIGHT.

GAGAN

&&

SGF WATCHES/WARNINGS/ADVISORIES...
MO...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR MOZ055>058-066>071-
077>083-088>098-101>106.

KS...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR KSZ073-097-101.

&&

$$

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