Friday, May 28, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 290446
AFDSGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1146 PM CDT FRI MAY 28 2010

..UPDATE TO AVIATION...

DISCUSSION...

LITTLE IN THE WAY OF APPRECIABLE FORECAST CHALLENGES OVER WHAT
APPEARS TO BE A BEAUTIFUL HOLIDAY WEEKEND...BEFORE A MORE UNSETTLED
WEATHER PATTERN TAKES HOLD ACROSS THE AREA EARLY NEXT WORK WEEK.

HIGH PRESSURE CONTINUES TO STRETCH FROM THE GREAT LAKES SOUTHWEST
ACROSS THE EASTERN PLAINS AND MISSISSIPPI VALLEY TODAY...WITH STRONG
RIDGING REMAINING IN PLACE ALOFT. AS WAS THE CASE ON
THURSDAY...MORNING RAOBS SHOWED VERY DRY AIR ALOFT...AND THIS
COMBINED WITH LARGE SCALE SUBSIDENCE SHOULD RESULT IN ONLY SOME
DIURNALLY DRIVEN CU LATE THIS AFTERNOON THAT SHOULD ALL BUT
DISAPPEAR SHORTLY AFTER SUNSET. WITH CLEAR SKIES AND LIGHT WINDS IN
PLACE...TEMPERATURES THIS EVENING SHOULD DROP RATHER QUICKLY THROUGH
THE 70S...WITH MORNING LOWS BOTTOMING OUT IN THE UPPER 50S TO AROUND
60 DEGREES.

HIGH PRESSURE LARGELY REMAINS IN CONTROL ON SATURDAY AS IT DRIFTS
OFF TO THE EAST ACROSS THE UPPER OHIO VALLEY. LATE SATURDAY...A
VERY WEAK SHORTWAVE CURRENTLY EVIDENT ON WATER VAPOR IMAGERY OVER
THE BOOTHEEL OF MISSOURI AND FAR WESTERN KENTUCKY IS EXPECTED TO
FORM A BROAD CLOSED UPPER LOW OVER THE SOUTHEASTERN U.S. COAST.
THIS LOW WILL THEN SLOWLY RETROGRADE BACK WEST OVER THE DEEP SOUTH
ON SUNDAY. A FEW SHOWERS OR THUNDERSTORMS MAY DRIFT INTO MAINLY THE
FAR SOUTHEASTERN CWA IN ASSOCIATION WITH THIS LOW...BUT THE BULK OF
THE ACTIVITY SHOULD REMAIN TO THE SOUTH.

MEANWHILE...A STRONGER SHORTWAVE/UPPER LOW CURRENTLY OVER THE
INTERMOUNTAIN WEST WILL EJECT NORTHEAST OVER THE NORTHERN ROCKIES
LATE SATURDAY AND EARLY SUNDAY. THIS SHOULD RESULT IN A FLATTENING
OF THE UPPER RIDGE AND BREAKDOWN OF THE NEAR-OMEGA BLOCK THAT HAS
BEEN IN PLACE OVER THE CENTRAL CONUS OVER THE LAST WEEK OR SO. WITH
UPPER FLOW BECOMING ZONAL BY MONDAY...A WEAK COLD FRONT ASSOCIATED
WITH THE WESTERN SHORTWAVE WILL DRIFT SOUTH ACROSS THE AREA SUNDAY AND
MONDAY BEFORE STALLING OUT SOMEWHERE ACROSS THE OZARKS LATE MONDAY
AND TUESDAY. WITH THIS BOUNDARY IN THE AREA...IT WOULD APPEAR THAT
DAILY THUNDERSTORM CHANCES WILL BE POSSIBLE. AT THIS POINT...SEVERE
WEATHER CHANCES DON'T LOOK TO BE TOO TERRIBLY HIGH NEXT WEEK. THE
BEST CHANCE FOR ANY ORGANIZED SEVERE WEATHER WOULD LIKELY COME LATE
SUNDAY OR EARLY MONDAY AS THE FRONT INITIALLY DROPS SOUTH...THOUGH
EXPECT THE HIGHEST CHANCES TO REMAIN WEST OF THE SGF CWA WHERE UPPER
LEVEL SUPPORT/SHEAR WILL BE MAXIMIZED.

THIS FRONT WILL LIKELY LIFT SLOWLY NORTHEAST WEDNESDAY AS A WARM
FRONT AS ANOTHER AREA OF LOW PRESSURE TAKES SHAPE IN THE LEE OF THE
COLORADO ROCKIES. DETAILS BEYOND WEDNESDAY BECOME A LITTLE
MUDDLED....WITH THE ECMWF MAINTAINING A STRONGER MID CONUS RIDGE AND
TAKING THE COLORADO LOW FURTHER NORTH...WITH THE GFS AND ITS
ENSEMBLE MEAN FAVORING A MORE SOUTHERLY TRACK. THE MAIN CONSEQUENCE
OF THE EVENTUAL OUTCOME WILL BE WHETHER THE FRONTAL BOUNDARY
ASSOCIATED WITH THIS LOW MOVES SOUTH OF THE AREA LATE IN THE
WEEK...OR ONCE AGAIN STALLS OUT ACROSS CENTRAL MISSOURI. AT THIS
POINT...HAVE FAVORED SOMEWHAT OF A BLEND OF THE TWO...WITH A
SLOWER...BUT STILL COMPLETE FRONTAL PASSAGE AT THE BEGINNING OF NEXT
WEEKEND. AT ANY RATE...A SLIGHT CHANCE TO CHANCE OF THUNDERSTORMS
SEEMS LIKE A PRETTY GOOD BET GOING INTO NEXT WEEKEND.

BOXELL

&&

AVIATION...

FOR THE 06Z TAF PACKAGE...PREDOMINATELY VFR CONDITIONS ARE
EXPECTED FOR THE NEXT 24 HOURS AND BEYOND. THERE IS A LOW CHANCE
FOR BRIEF MVFR VIS AT SUNRISE...THOUGH AN INFLUX OF DRIER AIR FROM
THE NORTHEAST WILL LIKELY PREVENT THIS. OUTSIDE OF A FEW DAYTIME
CUMULUS CLOUDS AND LIGHT EASTERLY WINDS...NO ADDITIONAL SENSIBLE
WEATHER CONCERNS ARE NOTED.

GAGAN

&&

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

$$

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