Severe Thunderstorm Warning 165, NWS Springfield, MO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
359 AM CDT SUN MAY 4 2003

...POSSIBLE SEVERE WEATHER OUTBREAK THIS AFTERNOON AND EVENING
IS THE MAIN FORECAST CONCERN...

EARLY THIS MORNING...WARM FRONT STRETCHED FROM SOUTHERN
ARKANSAS...THROUGH CENTRAL OKLAHOMA...TO SOUTHWEST KANSAS. PROFILERS
INDICATED A 45 TO 60 KT 850 MB JET WAS IMPINGING ON THIS BOUNDARY.
ELEVATED CONVECTION FIRED ACROSS FROM CENTRAL KANSAS NORTHEASTWARD
INTO NORTHERN MISSOURI. SO FAR THESE THUNDERSTORMS HAVE STAYED JUST
NORTH OF THE FORECAST AREA.  IN THE MORNING GRIDS...HAVE 50 POPS
GOING IN MY FAR NORTHERN COUNTIES WITH LESSER CHANCES TO THE SOUTH.
LOOKS LIKE THE BEST MOISTURE TRANSPORT WILL CONTINUE TO FOCUS THE
MAJORITY OF CONVECTION NORTH OF OUR AREA.

NEXT CONCERN IS THE ONGOING WIND ADVISORY. LOOKS AS IF THE WESTERN
HALF OF THE FORECAST HAS THE HIGHEST LIKELIHOOD OF VERIFYING.  A
SURFACE LOW WILL QUICKLY INTENSIFY AS A STRONG WAVE PUSHES INTO THE
PLAINS.  OUR WESTERN COUNTIES WILL HAVE TWO FACTORS IN FAVOR OF HIGH
WINDS. THE FIRST IS THE INCREASING PRESSURE GRADIENT...AND THE
SECOND IS THE MIXING DOWN OF STRONG WINDS ALOFT.  THE MESOETA
INDICATES A PUNCH OF DRIER AIR MOVING IN FROM THE WEST BY LATE
MORNING ACROSS EASTERN KANSAS AND WESTERN MISSOURI.  IF CLOUDS
CLEAR...WIND GUSTS IN EXCESS OF 40 MPH ARE POSSIBLE...AS INDICATED
BY BUFKIT SOUNDINGS.

NOW FOR THE MAIN CONCERN...PARAMETERS SETTING UP FOR A SIGNIFICANT
SEVERE WEATHER EVENT THIS AFTERNOON AND EVENING IF MORNING CLOUDS
CAN CLEAR OUT.  A DRYLINE WILL SURGE EASTWARD TODAY ACROSS
KANSAS...AS THE AFOREMENTIONED LOW PRESSURE SYSTEM DEEPENS AND
TRACKS TOWARD IOWA. THE STRONG SOUTHERLY WINDS WILL TRANSPORT
ABUNDANT LOW-LEVEL MOISTURE INTO THE REGION.  THE MESOETA EVEN SHOWS
THIN BAND OF 70 DEGREE DEWPOINTS ALONG THE KANSAS/MISSOURI BORDER BY
21Z. THIS IS NOT OUT OF THE QUESTION...AS 70 DEGREE DEWPOINT VALUES
ARE CURRENTLY FOUND ACROSS SOUTHEAST OKLAHOMA AND NORTHEAST TEXAS.
THE KAIN-FRITSCH VERSION OF THE ETA INDICATES CONVECTIVE INITIATION
BETWEEN 19Z AND 21Z SOMEWHERE NEAR THE KANSAS/MISSOURI BORDER. THIS
TIMING LOOKS PRETTY GOOD...AS A STRONG WAVE WILL BE PUSHING INTO THE
AREA...ALONG WITH A 120 KT UPPER LEVEL JET. THE STORMS SHOULD BE IN
THE FORM OF SUPERCELLS AT THE START OF THE EVENT...AND MAY EVOLVE
INTO A SQUALL LINE...DURING THE EVENING HOURS AS THEY MARCH ACROSS
MISSOURI. IF CLEARING OCCURS...LATE AFTERNOON CAPES SHOULD RANGE
FROM NEAR 4000 J/KG ACROSS FAR EASTERN KANSAS...TO AROUND 1000 J/KG
ACROSS CENTRAL MISSOURI.  PARAMETERS FOR TORNADIC SUPERCELLS ARE
VERY FAVORABLE THIS AFTERNOON AND EVENING. ENERGY HELICITY INDEX
VALUES RANGE FROM 3 TO 5.5 AT 00Z. IN ADDITION...VGP VALUES RANGE
FROM 0.3 TO 0.45. VALUES ABOVE 0.27 ARE CONSIDERED VERY FAVORABLE.
LOW SURFACE DEWPOINT DEPRESSIONS ALSO ADD TO THE TORNADO THREAT...AS
DEPRESSIONS ARE FORECAST TO BE 10 DEG F OR LESS.

.SGF...
MO...WIND ADVISORY TODAY.
KS...WIND ADVISORY TODAY.

SAW

KSZ073-097-101-MOZ055>058-066>071-077>083-088>098-101>106-041100-

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1025 PM CDT SAT MAY 3 2003

...OUTBREAK OF SEVERE THUNDERSTORMS AND TORNADOES POSSIBLE SUNDAY...

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

.DAY ONE...TONIGHT.

  WEATHER HAZARDS EXPECTED:

  ISOLATED SEVERE THUNDERSTORMS WITH HAIL UP TO THE SIZE OF
  QUARTERS.

  LOCALLY HEAVY RAINFALL OF ONE TO TWO INCHES...AND MINOR FLOODING.

  AREAS AFFECTED AND TIMING:

  THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL AND HAIL WILL MOVE INTO
  THE WESTERN PORTIONS OF THE OUTLOOK AREA BETWEEN 1 AND 4 AM...
  AND OVERSPREAD THE MISSOURI OZARKS DURING THE EARLY MORNING HOURS
  SUNDAY. THE ENTIRE OUTLOOK AREA IS AT RISK FOR LARGE HAIL AND
  HEAVY RAINFALL.

  DISCUSSION:

  A WARM FRONT WILL LIFT NORTHWARD ACROSS THE OUTLOOK AREA TONIGHT.
  A COMPLEX OF THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT AND
  MOVE ACROSS THE AREA OVERNIGHT. A FEW OF THE STORMS COULD BECOME
  SEVERE WITH LARGE HAIL THE PRIMARY THREAT. LOCALLY HEAVY RAINFALL
  AND MINOR FLOODING IS POSSIBLE. HOWEVER THE FORECASTED FAST
  MOVEMENT OF THE THUNDERSTORMS WILL LIMIT THE POTENTIAL OF
  FLOODING AND WIDESPREAD HEAVY RAINFALL.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

  A SIGNIFICANT SEVERE WEATHER EVENT WILL BE POSSIBLE SUNDAY
  AFTERNOON AND EVENING.

  OVERNIGHT THUNDERSTORMS WILL EXIT THE EASTERN PORTIONS OF THE
  OUTLOOK AREA BY MID MORNING. A FEW OF THESE STORMS MAY STILL BE
  CAPABLE OF PRODUCING QUARTER SIZE HAIL BEFORE EXITING THE AREA BY
  AROUND 10 AM.

  SKIES ARE THEN FORECAST TO BECOME PARTLY SUNNY IN THE WAKE OF THE
  THUNDERSTORMS. VERY STRONG SOUTHERLY WINDS ARE LIKELY...WITH
  SUSTAINED WINDS IN EXCESS OF 30 MPH AND GUSTS TO 45 MPH LIKELY.
  THESE STRONG WINDS WILL DRAW HUMID AIR NORTHWARD INTO THE OUTLOOK
  AREA. THE INCREASE IN HUMIDITY COMBINED WITH DAYTIME HEATING WILL
  CREATE A VERY UNSTABLE AIRMASS. THE STRONG INSTABILITY AND
  EXTREMELY FAVORABLE WINDS ALOFT WILL FAVOR THE RAPID DEVELOPMENT
  OF SEVERE THUNDERSTORMS BY EARLY TO MID AFTERNOON. HAIL TO THE
  SIZE OF GOLF BALLS OR LARGER...DAMAGING WINDS IN EXCESS OF 70
  MPH...AND TORNADOES ARE ALL POSSIBLE IN THE OUTLOOK AREA SUNDAY
  AFTERNOON AND EVENING.

  MANY VARIABLES NEED TO COME TOGETHER TO SUPPORT A SIGNIFICANT
  SEVERE WEATHER OUTBREAK AND IF JUST ONE DOESNT MATERIALIZE THEN
  THE THREAT OF SEVERE WEATHER IS GREATLY DIMINISHED. IF CLOUDS
  LINGER AND STRONG INSTABILITY DOES NOT MATERIALIZE...SEVERE
  WEATHER POTENTIAL WILL BE LIMITED. AT THIS TIME IT STILL APPEARS
  AS THOUGH A MAJOR OUTBREAK OF SEVERE THUNDERSTORMS...INCLUDING
  TORNADOES...IS POSSIBLE SUNDAY.

.SPOTTER INFORMATION STATEMENT...

  SPOTTER ACTIVATION IS NOT EXPECTED TONIGHT DUE TO THE ISOLATED
  NATURE OF SEVERE WEATHER.

  DUE TO THE POTENTIAL OF A SIGNIFICANT SEVERE WEATHER OUTBREAK
  SUNDAY...EMERGENCY MANAGERS...HAM RADIO OPERATORS...STORM
  SPOTTER GROUPS...LAW ENFORCEMENT AGENCIES...AND ALL PERSONS WITH
  INTERESTS IN THE OUTLOOK AREA SHOULD CLOSELY MONITOR LATER
  FORECASTS AND OUTLOOKS ISSUED BY THE NATIONAL WEATHER SERVICE
  IN SPRINGFIELD.

&&

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

FOSTER