Tuesday, April 27, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 270546
AFDSGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1246 AM CDT TUE APR 27 2010

..UPDATE TO AVIATION...

SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...

CURRENTLY...BRISK AND GUSTY WEST TO NORTHWESTERLY WINDS ARE
OCCURRING ACROSS THE REGION...AS A TIGHT PRESSURE GRADIENT IS IN
PLACE ACROSS THE AREA. AN UPPER LEVEL LOW IS CURRENTLY PUSHING
SOUTH INTO NORTHWESTERN MISSOURI THIS AFTERNOON.

THIS UPPER LEVEL LOW WILL CONTINUE TO DIVE SOUTH INTO AND THROUGH
THE AREA OVERNIGHT INTO TUESDAY. MOISTURE IS LIMITED ACROSS THE
AREA...BUT THIS SYSTEM WILL HAVE ENOUGH LIFT THAT SCATTERED SHOWERS
WILL BE POSSIBLE ACROSS THE AREA LATE THIS AFTERNOON INTO THE
OVERNIGHT HOURS. THERE MAYBE JUST ENOUGH INSTABILITY FOR A RUMBLE
OF THUNDER OR TWO TO BE POSSIBLE WITHIN THIS ACTIVITY LATE THIS
AFTERNOON INTO THE EARLY EVENING HOURS. THE BEST CHANCES FOR ANY
MEASURABLE RAIN WITH THIS SYSTEM WILL BE OVER CENTRAL MISSOURI...WITH
ONLY LIGHT AMOUNTS EXPECTED. THERE COULD BE SOME LINGERING LIGHT
RAIN/DRIZZLE ACROSS THE EASTERN CWA INTO TUESDAY.

A REINFORCING SHOT OF COOLER AIR WILL SPREAD INTO THE AREA BEHIND
THIS SYSTEM. HIGHS ON TUESDAY WILL STRUGGLE TO WARM OUT OF THE
50S AS THE COLDER AIRMASS WILL BE OVER HEAD. A WARMING TREND WILL
THEN BEING ON WEDNESDAY AS UPPER LEVEL RIDGING BUILDS TOWARDS THE
AREA.

WISE

&&
LONG TERM (THURSDAY THROUGH MONDAY)...

THE FORECAST CHALLENGE DURING THE LATTER PORTION OF THE WEEK AND INTO
THE WEEKEND WILL BE THE THE PATTERN MORPHOLOGY AND TIMING OF A
FRONTAL SYSTEM SUPPORTED BY A DEEPENING THROUGH OVER THE WESTERN
UNITED STATES. BOTH LONG RANGE MODELS FORECAST THE UPPER LEVEL
TROUGH DEEPENING SIGNIFICANTLY TO THE WEST. HOWEVER... THE
SOLUTIONS DIFFER SIGNIFICANTLY WITH REGARDS TO THE DETAILS OF THE
SURFACE LOW AND FRONTAL POSITION AND PROGRESSION. THE GFS SOLUTION
IS MUCH MORE PROGRESSIVE WITH THE FRONTAL MOVEMENT TO THE EAST.
THE ECMWF SOLUTION GENERATES LEE SIDE CYCLOGENESIS OVER COLORADO
AT THE NOSE OF INCOMING JET STREAM. GIVEN SOLID ECMWF MODEL
PERFORMANCE HISTORY AND THE FACT THAT LEE SIDE CYCLOGENESIS IN
THIS REGIME IS FAVORABLE... HAVE LEANED HEAVILY ON THE ECMWF
SOLUTION FOR THE FORECAST. WITH THIS SOLUTION... THE BEST CHANCES
FOR PRECIPITATION WILL BE ON FRIDAY WITH THE MAIN FRONTAL
PASSAGE. GIVEN MODEL UNCERTAINTY... DETERMINING SEVERE WEATHER
PROBABILITIES FOR FRIDAY REMAINS UNCERTAIN AT THIS TIME.

FOR EARLY NEXT WEEK... MODEL GUIDANCE SHOWS FURTHER INCONSISTENCY.
THE GFS SOLUTION PUTS THE AREA SQUARELY IN SOUTHWEST FLOW... LENDING
MORE TOWARD HEAVY RAIN AND POSSIBLE FLOODING. THE ECMWF SOLUTION
BRINGS A STRONG NEGATIVELY TILTED TROUGH OVER THE AREA... LENDING
MORE TOWARD AN EPISODE OF SEVERE WEATHER.

KARDELL

&&

AVIATION...

AN UPPER LEVEL LOW CENTERED OVER THE CENTRAL OZARKS WILL TRACK
SOUTHEAST THROUGH THE MISSOURI OZARKS. NORTHWEST SURFACE WINDS
BEHIND AN ASSOCIATED FRONT ARE EXPECTED TO INCREASE EARLY THIS
MORNING. IN ADDITION...CEILINGS LOWERING TO MVFR WILL BE
POSSIBLE. CEILINGS WILL RAISE TO VFR BY NOON AIDED BY MIXING.
SURFACE WINDS WILL DIMINISH WITH THE DEPARTURE OF THE LOW TO THE
SOUTHEAST AND A RELAXING PRESSURE GRADIENT ALONG WITH SKIES
BECOME SKC NEAR SUNSET.

ANGLE

&&

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

$$


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