Sunday, April 25, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 250557
AFDSGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1257 AM CDT SUN APR 25 2010

..UPDATE TO PUBLIC AND AVIATION...

UPDATE...

HAVE REMOVED THUNDER FROM SOUTHERN MISSOURI FOR THE REMAINDER OF
TONIGHT AS LIFT AND INSTABILITY HAVE DROPPED TO NIL. ONLY OTHER
CHANGE WAS TO INCREASE POPS ACROSS CENTRAL MISSOURI AS A BAND OF
LIGHT SHOWERS ASSOCIATED WITH THE MAIN UPPER LEVEL LOW ROTATE
SOUTHEAST INTO THE AREA.

SCHAUMANN

&&

DISCUSSION...

MAIN FORECAST CONCERNS IN THIS FORECAST PACKAGE WILL DEAL WITH
ONGOING SEVERE WEATHER THIS AFTERNOON INTO THE EARLY EVENING.

CURRENTLY...A STRONG UPPER LEVEL LOW IS PUSHING INTO WESTERN
MISSOURI THIS AFTERNOON. AHEAD OF THIS SYSTEM A STRONG LINE OF
STORMS HAS DEVELOP ALONG A LINE FROM PLEASANT HOPE TO GROVESPRING
THEN TO THE SOUTHEAST TO ALTON. DAMAGING WINDS HAVE BEEN REPORTED
ALONG THIS LINE WITH WINDS IN EXCESS OF 6O MPH.

A BREAK IN THE CLOUDS AHEAD OF THIS LINE OF STORMS HAS ALLOWED
INSTABILITY TO INCREASE ACROSS SOUTH CENTRAL MISSOURI WITH MLCAPE
VALUES IN THE 400 TO 800 J/KG RANGE. FARTHER TO THE NORTHEAST
INSTABILITY IS WEAKER AS PREVIOUS STORMS HAVE WORKED THE AREA
OVER...HOWEVER SOME INSTABILITY STILL EXISTS. THE LOW LEVEL FLOW
IS PERPENDICULAR TO THE LINE AND SHOULD HELP MAINTAIN THE LINE AS
IT PUSHES EAST NORTHEAST. SIGNIFICANT WIND SHEAR ALSO REMAINS IN
PLACE ACROSS THE EASTERN CWA WHICH WILL SUPPORT STRONG TO SEVERE
STORMS AS THIS LINE PUSHES INTO THIS AREA. THE PRIMARY SEVERE
HAZARD ASSOCIATED WITH THIS LINE WILL BE STRONG STRAIGHT LINE
WINDS. GIVEN THE STRONG WIND SHEAR...ISOLATED TORNADOES WITHIN THIS
LINE OF STORMS WILL ALSO REMAIN POSSIBLE ACROSS CENTRAL AND SOUTH
CENTRAL MISSOURI THIS AFTERNOON INTO THE EARLY EVENING HOURS.
SMALL HAIL WILL ALSO BE POSSIBLE BUT SHOULD GENERALLY REMAIN BELOW
SEVERE THRESHOLDS.

EARLY THIS EVENING THIS LINE OF STORMS WILL PUSH EAST AND OUT OF
THE AREA AS THE SYSTEM CONTINUES TO PUSH EAST. THIS WILL BRING AN
END TO THE SEVERE THREAT. ON THE BACK SIDE OF THE LOW...WRAP
AROUND SCATTERED SHOWERS WILL REMAIN POSSIBLE INTO SUNDAY. THE
BEST CHANCES FOR THIS RAINFALL WILL BE ACROSS THE NORTHERN AND
EASTERN CWA. WIDE SPREAD FLOODING IS NOT EXPECTED...BUT LOCALIZED
FLOODING OF FLOOD PRONE AREAS WILL BE POSSIBLE THIS AFTERNOON AND
EVENING.

ANOTHER WEAK STORM SYSTEM WILL DIVE SOUTH THROUGH THE REGION EARLY
THIS WEEK. THIS DISTURBANCE MAY BRING SCATTERED SHOWERS TO THE
AREA...ESPECIALLY ACROSS THE EASTERN CWA MONDAY INTO TUESDAY.
INSTABILITY WILL BE LIMITED SO NO THUNDERSTORMS ARE EXPECTED. AN
UPPER LEVEL RIDGE WILL THEN BUILD INTO THE AREA BY MID TO LATE
WEEK...RETURNING HIGHS IN THE 80S BY THURSDAY. ANOTHER STRONG
STORM SYSTEM IS THEN EXPECTED TO AFFECT THE REGION LATE NEXT WEEK.
THIS SYSTEM WILL BRING ADDITIONAL THUNDERSTORM CHANCES TO THE
AREA. DIFFERENCES REMAIN BETWEEN THE MEDIUM RANGE MODELS WITH
REGARDS TO THE TIMING OF THIS SYSTEM. WILL HAVE TO MONITOR THIS
SYSTEM AND TRY TO GET A BETTER HANDLE ON THE EXACT TRACK AND
TIMING WITH FUTURE MODEL RUNS TO BE ABLE TO DETERMINE THE SEVERE
POTENTIAL.

&&

AVIATION...

A DECK OF STRATOCUMULUS WILL PUSH SOUTHEAST INTO THE AREA LATE
TONIGHT AND SUNDAY MORNING. EXACT TIMING OF ONSET IS STILL IN
QUESTION...BUT CONFIDENCE IS HIGH THAT MVFR CEILINGS WILL BEGIN TO
IMPACT ALL SOUTHWEST MISSOURI TAF SITES SOMEWHERE IN THE 11Z TO
16Z TIME RANGE. MVFR CEILINGS SHOULD THEN PERSIST FOR MUCH OF THE
DAY...WITH CEILINGS BEGINNING TO COME UP LATE IN THE AFTERNOON AND
EVENING. DID INCLUDE VCSH IN PREVAILING GROUP AT KSGF INTO SUNDAY
MORNING AS LIGHT SHOWERS PUSH OUT OF CENTRAL MISSOURI AND INTO THE
GENERAL VICINITY. BRISK WEST TO NORTHWEST WINDS WILL DEVELOP
SUNDAY MORNING...BECOMING GUSTY IN THE LATE MORNING AND
AFTERNOON.

SCHAUMANN

&&

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

$$


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