Monday, August 30, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 301059
AFDSGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
559 AM CDT MON AUG 30 2010

..UPDATE TO AVIATION...

DISCUSSION...
/ISSUED 330 AM CDT MON AUG 30 2010/

MAIN FOCUS IN THIS FORECAST PACKAGE WILL DEAL WITH TEMPERATURES
AND SCATTERED SHOWER AND THUNDERSTORM POTENTIAL TODAY...THEN
ATTENTION TURNS TO BETTER CHANCES FOR WIDESPREAD RAINFALL AHEAD OF
AND ASSOCIATED WITH A SURFACE COLD FRONT WEDNESDAY INTO THURSDAY
EVENING.

CURRENTLY...UPPER LEVEL RIDGE OF HIGH PRESSURE REMAINS LOCKED IN PLACE
ACROSS THE EAST COAST AS AN UPPER LEVEL TROUGH IS LOCATED ACROSS
THE WEST COAST. TROPICAL MOISTURE CONTINUES TO MOVE OUT OF THE
GULF INTO THE EASTERN CWA EARLY THIS MORNING. DRIER AIR HOWEVER
REMAINS IN PLACE ACROSS THE WESTERN CWA AND IS SLOWING THE
WESTWARD MOVEMENT OF THE MOISTURE. A LOW LEVEL STRATUS CLOUD DECK HAS
SPREAD INTO THE EASTERN PORTIONS OF THE CWA WITHIN THIS MOISTURE
PLUME. THERE IS ALSO A WEAK UPPER LEVEL DISTURBANCE WITHIN THIS
MOISTURE PLUME ACROSS NORTHERN MISSISSIPPI WHICH IS RESULTING IN A
FEW SHOWERS ACROSS NORTHEASTERN ARKANSAS EARLY THIS MORNING.

THE SHOWER ACTIVITY ACROSS NORTHEASTERN ARKANSAS SHOULD CONTINUE
TO LIFT NORTH INTO SOUTH CENTRAL MISSOURI THIS MORNING. THIS
ACTIVITY WILL BE ISOLATED TO SCATTERED IN NATURE AND OVERALL NOT
OVERLY HEAVY. INSTABILITY SHOULD INCREASE ENOUGH FROM MID MORNING
INTO THE AFTERNOON HOURS TO ALLOW FOR SOME ISOLATED TO SCATTERED
THUNDERSTORMS WITHIN THIS ACTIVITY. NO SEVERE WEATHER IS EXPECTED
WITH THIS ACTIVITY. THE BETTER MOISTURE WILL REMAIN ACROSS THE
EASTERN CWA AND OFF TO THE EAST...WHERE THE CONVECTION SHOULD
REMAIN.

TEMPERATURES WILL BE TRICKY TODAY DUE TO THE CLOUD COVER AND
CONVECTION POTENTIAL TODAY. THE STRATUS DECK WHICH HAS PUSHED INTO THE
AREA...HAS STARTED TO SLOW ITS NORTHWARD AND WESTWARD PUSH EARLY
THIS MORNING...BUT MAY STILL PUSH FARTHER TO THE WEST THIS
MORNING. WITH THE DRY MID LEVEL MOISTURE IN PLACE ACROSS THE WESTERN
CWA THIS CLOUD DECK SHOULD ERODE AND RETREAT BACK TO THE EAST THIS
AFTERNOON IF IT DOES SPREAD INTO THESE AREAS. WITH BETTER
MOISTURE ACROSS THE EASTERN CWA DO NOT KNOW HOW MUCH THIS CLOUD
DECK WILL BE ABLE TO ERODE THIS AFTERNOON THERE. THEREFORE...THINK
CLOUDS WILL HOLD ON ACROSS THE EASTERN CWA FOR MUCH OF THE
DAY...WITH PARTLY CLOUDY SKIES EXPECTED ACROSS THE WESTERN CWA.
EXPECTED TEMPERATURES TO WARM INTO THE 90S ACROSS EXTREME
SOUTHEAST KANSAS AND FAR WESTERN AND SOUTHWESTERN MISSOURI DUE TO
THE EXPECTED BREAKS IN THE CLOUDS AND WITH A WARM AIRMASS STILL IN
PLACE ACROSS THE AREA. THE CLOUD COVER TO THE EAST THOUGH SHOULD
REALLY LIMIT HIGHS THIS AFTERNOON...WITH HIGHS IN THE LOW TO MID
80S EXPECTED. THEREFORE...A TEN DEGREE DIFFERENCE IN HIGHS FROM
THE WESTERN TO EASTERN CWA WILL LIKELY OCCUR THIS AFTERNOON.

THIS EVENING INTO TONIGHT...THE TROPICAL MOISTURE PLUME SHOULD LIFT
TO THE NORTH AND EAST WITH THE DRIER AIRMASS TO THE WEST ALLOWED
TO SPREAD BACK TO THE EAST ACROSS THE ENTIRE AREA. THIS SHOULD LIMIT
ANY PRECIPITATION CHANCES THROUGH THIS PERIOD.

MOISTURE WILL THEN START TO SPREAD INTO THE AREA FROM THE WEST
ON TUESDAY AHEAD OF THE NEXT SYSTEM. THERE WILL BE THE POSSIBILITY
FOR A FEW ISOLATED SHOWERS AND THUNDERSTORMS ACROSS THE
AREA...GENERALLY DURING THE PEAK HEATING TIME FRAME. THE BETTER
CHANCES WILL BE ACROSS THE WESTERN CWA WHERE THE BETTER MID LEVEL
MOISTURE WILL RESIDE...HOWEVER THIS ACTIVITY WILL STILL NOT BE
WIDESPREAD BY ANY MEANS.

THE UPPER LEVEL TROUGH WILL PUSH EAST ACROSS THE NORTHERN AND
CENTRAL PLAINS ON WEDNESDAY INTO THURSDAY. THIS FEATURE WILL
FLATTEN THE UPPER LEVEL RIDGE AND ALLOW FOR A COLD FRONT TO PUSH
TOWARDS AND THROUGH THE AREA LATE WEDNESDAY NIGHT INTO THURSDAY
EVENING. WIDESPREAD RAINFALL CHANCES WILL BEGIN TO INCREASE ACROSS
THE NORTHERN CWA ON WEDNESDAY AND WEDNESDAY NIGHT AHEAD OF THE
FRONT. THEN ACROSS THE ENTIRE AREA ON THURSDAY AS THE FRONT PASSES
THROUGH THE AREA. THE BETTER SHEAR AND UPPER LEVEL SUPPORT WILL
REMAIN TO THE NORTH OF THE AREA WHERE THE SEVERE WEATHER POTENTIAL
SHOULD REMAIN. SOME CONVECTION MAY LINGER ACROSS THE SOUTHERN CWA
THROUGH THURSDAY NIGHT...BUT BY THE LARGE PART MOST OF THE
CONVECTION SHOULD PUSH SOUTH OF THE AREA THURSDAY EVENING. THE GFS
STILL REMAINS SLIGHTLY SLOWER THAN THE ECMWF FOR THE TIMING OF
THIS SYSTEM AND HAVE CONTINUED TO FOLLOW MORE IN LINE WITH THE
MORE PROGRESSIVE ECMWF SOLUTION WITH REGARDS TO THE TIMING OF THIS
SYSTEM.

NORTHWEST FLOW ALOFT AND COOLER CONDITIONS WILL THEN SPREAD INTO
THE AREA BEHIND THE FRONT FRIDAY INTO THE WEEKEND. MAY HAVE TO
WATCH FOR AN UPPER LEVEL DISTURBANCE TRYING TO OVERRIDE THE
NORTHWEST FLOW INTO THE AREA SATURDAY NIGHT INTO SUNDAY...BUT IT
WILL BE HARD TO PINPOINT THE EXACT TRACK AND TIMING OF THIS
DISTURBANCE AT THIS TIME AS THIS WILL BE MORE OF A MESOSCALE
ISSUE.

WISE

&&

AVIATION...

FOR THE 12Z TAFS...LOW LEVEL MOISTURE CONTINUES TO ADVECT INTO THE
REGION FROM THE SOUTHEAST THIS MORNING. STRATUS DECK HAS DEVELOPED
ACROSS THE MAJORITY OF THE CWA WITH THE LOWEST CEILINGS OVER SOUTH
CENTRAL MISSOURI WHICH IS IN LINE WITH WHERE THE SREF HAD THE
HIGHEST PROBABILITIES OF IFR CEILINGS OVERNIGHT. SGF/JLN WILL
LIKELY REMAIN IN MVFR CATEGORY THIS MORNING WITH BBG IN THE IFR.
CEILINGS WILL BEGIN TO SCATTER OUT BY LATE MORNING TO EARLY
AFTERNOON AND WILL HOLD ON THE LONGEST AT BBG.

LINDENBERG

&&

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

$$


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