Severe Thunderstorm Warning 256, NWS Springfield, MO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
245 PM CDT SAT JUL 24 2004

.DISCUSSION...
A COMPLEX AND UNUSUAL PATTERN FOR LATE JULY ACROSS THE CENTRAL U.S.
AN UPPER TROUGH CONTINUES TO SAG SOUTH INTO THE NORTHERN U.S. WHILE
CANADIAN HIGH PRESSURE BUILDS SOUTH INTO THE UPPER MIDWEST. AN
INVERTED SURFACE TROUGH HAD DEVELOPED NORTH INTO FAR SOUTHEAST
KANSAS AHEAD OF A SLOW MOVING VORTICITY CENTRAL JUST EAST OF
WICHITA. A SECONDARY WARM FRONT AHEAD DEVELOPED EAST OF THIS
CIRCULATION ACROSS SOUTHERN MISSOURI.

A STEADY RAIN CONTINUED NORTH OF THIS WARM FRONT IN AREA OF GOOD
ISENTROPIC LIFT AND 850 MB MOISTURE CONVERGENCE. SHOWERS WERE
SCATTERED IN THE PSEUDO WARM SECTOR. TEMPERATURES HAVE STRUGGLED TO
RISE AND HAVE EVEN FALLEN NORTH OF THE FRONT ACROSS CENTRAL MISSOURI
WHERE AFTERNOON TEMPERATURES WERE ONLY IN THE UPPER 50S

THERE HAS BEEN SOME CONCERN ABOUT THE DEVELOPMENT OF LOW TOPPED
SUPERCELLS IN THE WARM SECTOR OF FAR SOUTHWEST MISSOURI AND EXTREME
SOUTHEAST KANSAS THIS AFTERNOON. CLEARING AND RESULTING INSTABILITY
HAS BEEN LIMITED TO THIS POINT BUT SITUATION WILL BE MONITORED THE
NEXT FEW HOURS. SEE THE PREVIOUSLY ISSUED DISCUSSION FOR DETAILS.

THE VORTICITY CENTER AND MID LEVEL TROUGH AXIS WILL MIGRATE EAST
SOUTHEAST TONIGHT AS THE SYNOPTIC SCALE TROUGH AXIS SWINGS
SOUTHEAST. THE HEAVIEST AND MOST STEADY RAIN WILL OCCUR THIS EVENING
IN AREA OF STRONGEST 850-700 MB MOISTURE CONVERGENCE/THETA-E
ADVECTION AHEAD OF THE MID LEVEL TROUGH. DEEP SATURATED LAYER AND
ISENTROPIC ASCENT WILL PERSIST AHEAD OF THE TROUGH. WIDESPREAD RAIN
WILL PERSIST TONIGHT WITH THE STEADIEST  RAINFALL ACROSS CENTRAL
MISSOURI IN REGION BETTER ISENTROPIC LIFT. ANY THUNDERSTORMS THAT
DEVELOP WILL END EARLY THIS EVENING.

THIS SYSTEM WILL BE SLOW TO CLEAR OUT SUNDAY WITH CLOUDS LINGERING
THROUGH THE DAY ACROSS MUCH OF THE FORECAST AREA. AREAS OF LIGHT
RAIN WILL CONTINUE INTO THE MORNING BEFORE TAPERING OFF. A
STEEPENING PRESSURE GRADIENT BETWEEN THE EXITING SURFACE TROUGH AND
A LARGE PRESSURE SYSTEM DROPPING INTO PLAINS AND UPPER MIDWEST WILL
CAUSE RATHER BRISK NORTHEAST WINDS FOR LATE JULY. HIGH TEMPERATURES
WILL STRUGGLE TO RISE OUT OF THE 60S IF THE CLOUDS PERSIST.

THE BELOW NORMAL TEMPERATURES WILL PERSIST INTO EARLY NEXT WEEK AS
THE SURFACE HIGH BUILDS ACROSS THE REGION. HOWEVER MORE SUNSHINE
WILL RETURN MONDAY ALLOWING TEMPERATURES TO RISE WELL INTO THE 70S.

THE UPPER PATTERN WILL FLATTEN BY MIDWEEK IN THE WAKE OF THE
DEPARTING TROUGH. INCREASING MOISTURE IN RETURN FLOW AND THE
APPROACH OF A SHORTWAVE MAY BRING THE CHANCE OF SHOWERS BACK TO THE
FORECAST AREA LATE WEDNESDAY AND THURSDAY.

&&

.AVIATION...
WIDESPREAD MVFR WILL CONTINUE THROUGH SUNDAY MORNING. CEILINGS WILL
GENERALLY RANGE BETWEEN 1000 AND 2000 FEET. VISIBILITIES WILL LOWER
TO BETWEEN 2 AND 4 MILES AT TIMES IN RAIN AND FOG.

&&

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

FOSTER

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SPRINGFIELD MO
100 PM CDT SAT JUL 24 2004

KSZ073-097-101-MOZ055>058-066>071-077>083-088>098-101>106-251100-
BARRY-BARTON-BENTON-BOURBON-CAMDEN-CEDAR-CHEROKEE-CHRISTIAN-CRAWFORD-
DADE-DALLAS-DENT-DOUGLAS-GREENE-HICKORY-HOWELL-JASPER-LACLEDE-
LAWRENCE-MARIES-MCDONALD-MILLER-MORGAN-NEWTON-OREGON-OZARK-PHELPS-
POLK-PULASKI-SHANNON-ST. CLAIR-STONE-TANEY-TEXAS-VERNON-WEBSTER-
WRIGHT-
INCLUDING THE CITIES OF...AVA...BOLIVAR...BRANSON...CAMDENTON...
FORT LEONARD WOOD...FORT SCOTT...HOUSTON...JOPLIN...LEBANON...
MONETT...MOUNT VERNON...NEOSHO...NEVADA...OSAGE BEACH...OZARK...
PITTSBURG...ROLLA...SPRINGFIELD...STOCKTON AND WEST PLAINS.
100 PM CDT SAT JUL 24 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE MISSOURI OZARKS AND EXTREME
SOUTHEAST KANSAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

  WEATHER HAZARDS EXPECTED:

  LOCALLY HEAVY RAINFALL AND MINOR FLOODING.

  ISOLATED TO SCATTERED THUNDERSTORMS...POSSIBLY WITH AN ISOLATED
  TORNADO.

  AREAS AFFECTED AND TIMING:

  THUNDERSTORMS POSSIBLE MAINLY SOUTH OF A FORT SCOTT TO CAMDENTON
  LINE THROUGH EARLY THIS EVENING.  LOCALLY HEAVY RAINFALL WILL BE
  POSSIBLE AREA WIDE THROUGH TONIGHT.

  DISCUSSION:

  ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS FAR
  SOUTHERN MISSOURI AND EXTREME SOUTHEAST KANSAS THIS AFTERNOON.
  SOUTHERLY WINDS HAVE DEVELOPED AHEAD OF A SURFACE LOW IN SOUTHEAST
  KANSAS. A COLD FRONT TRAILED SOUTH OF THIS LOW INTO NORTH
  CENTRAL OKLAHOMA. THE MOIST AND UNSTABLE AIRMASS COUPLED WITH WITH
  LIMITED SUNSHINE WILL RESULT IN INCREASING INSTABILITY. THE
  COVERAGE AND STRENGTH OF THUNDERSTORMS WILL BE DEPENDENT ON THE
  AMOUNT OF SUNSHINE THAT DEVELOPS.  SUFFICIENT INSTABILITY AND LOW
  LEVEL WIND SHEAR MAY BE DEVELOP TO PRODUCE A FEW LOW TOPPED
  SUPERCELLS. IF THIS OCCURS...AN ISOLATED TORNADO CANNOT BE RULED
  OUT ACROSS FAR SOUTHERN MISSOURI AND EXTREME SOUTHEAST KANSAS. ANY
  STORMS THAT FORM WILL BE CAPABLE OF PRODUCING VERY HEAVY RAINFALL
  AND LOCALIZED FLOODING...AND GUSTY WINDS.

  INTERMITTENT RAIN WILL CONTINUE ACROSS CENTRAL MISSOURI AS A
  WARM FRONT DEVELOPS ACROSS SOUTHERN MISSOURI. ADDITIONAL
  RAINFALL COULD RESULT IN MINOR FLOODING ACROSS CENTRAL MISSOURI
  INCLUDING THE LAKE OF THE OZARKS REGION WHERE MODERATE TO HEAVY
  RAINFALL HAS ALREADY FALLEN.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH FRIDAY.

  THE CHANCE OF THUNDERSTORMS WILL RETURN TO THE OUTLOOK AREA
  WEDNESDAY NIGHT AND THURSDAY.

.SPOTTER INFORMATION STATEMENT...

  SPOTTER ACTIVATION WILL LIKELY NOT BE REQUIRED THROUGH TONIGHT DUE
  TO THE ISOLATED NATURE OF THE STORMS. HOWEVER SPOTTER ACTIVATION
  WOULD BECOME MORE LIKELY IF LOW TOPPED SUPERCELLS DEVELOP.

&&

THIS PRODUCT IS NOW AVAILABLE IN GRAPHICAL FORMAT...ALONG WITH OTHER
WEATHER...HYDROLOGICAL AND CLIMATE INFORMATION...AT
HTTP://WWW.CRH.NOAA.GOV/SGF

FOSTER