Severe Thunderstorm Warning 500, NWS Springfield, MO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
645 AM CDT WED AUG 6 2003

...UPDATED FOR SHORT TERM AND 12Z AVIATION...

.DISCUSSION...

SHORT TERM...
ISOLATED CONVECTION OVER LSXS WILL PROBABLY CLIP THE FAR EASTERN
EDGES OUR OF CWA...GIVEN THE MINIMAL AREAL COVERAGE IN OUR CWA THE
GOING LOW CHANCE POPS SHOULD SUFFICE. ALSO...FOG HAS DEVELOPED IN
AREAS THAT SAW RAINFALL LAST EVENING AND WHERE IT CLEARED OUT
OVERNIGHT. BRIEF WINDOW OF OPPORTUNITY FOR DENSE FOG THIS MORNING
OVER MAINLY EASTERN PORTIONS OF THE CWA. UPDATED GRIDS/ZFP SENT
ABOUT AN HOUR AGO TO ACCOUNT FOR THE FOG...AND THE DENSE FOG SHOULD
REMAIN LOCALIZED ENOUGH TO PRECLUDE AN NPW.

IZZI

.PREVIOUS DISCUSSION...
ANOTHER NORTHWEST FLOW SHORTWAVE ALONG WITH ABUNDANT MOISTURE...LOTS
OF LEFTOVER CONVECTIVE BOUNDARIES...AND INSTABILITY LED TO ANOTHER
ROUND OF CONVECTION YESTERDAY AFTERNOON AND EVENING. THIS SHORTWAVE
HAS EXITED THE REGION BUT ANOTHER IS EVIDENT ON WATER VAPOR
SATELLITE IMAGERY OVER NORTHERN MO. SCATTERED SHOWERS ARE MOVING
SOUTHEAST THROUGH EAST CENTRAL MO. LOW LEVEL FOCUS FOR ADDITIONAL
STRONG CONVECTION IS LACKING IN THE VERY NEAR TERM...WITH SURFACE
BOUNDARY JUST SOUTH OF THE MO/AR STATE LINE AND LITTLE TO NO 850MB
MOISTURE CONVERGENCE/POOLING.

SOMEWHAT DRYER AIR HAS ADVECTED INTO CENTRAL MO TONIGHT....AND THIS
TREND IS CARRIED INTO THE DAYTIME HOURS TODAY BY FORECAST MODEL
GUIDANCE. MIDLEVEL FLOW PATTERN OVER THE CONUS WILL CONTINUE TO
BECOME MORE AMPLIFIED FOR THE REST OF THE WEEK. AS A RESULT...BOTH
THE ETA AND GFS PUSH THE FRONTAL BOUNDARY SOUTHWARD INTO THE
ARKLATEX AND LOWER MS VALLEY TONIGHT. THERE SHOULD STILL BE ENOUGH
MOISTURE AND SURFACE BASED INSTABILITY TODAY (ABOUT 2000 J/KG OFF
THE META THIS AFTERNOON) TO PRODUCE SOME CONVECTION. GOING 20
PERCENT CHANCE OF RAIN SHOULD COVER THIS FOR NOW. GIVEN THE
CONTINUED DEEP LAYER SHEAR IN THE PERSISTENT NORTHWEST MIDLEVEL FLOW
REGIME...IF/WHEN A STORM DEVELOPS IT CAN EASILY GO SEVERE...BUT
BELIEVE COVERAGE WILL BE MORE SPOTTY THAN YESTERDAY.

WILL CONTINUE THE DRY FORECAST PAST TONIGHT...WHICH AT FIRST BLUSH
SEEMS LOGICAL GIVEN THAT LOW LEVEL SYNOPTIC SCALE BOUNDARIES WILL BE
SOUTH OF THE AREA...THE MIDLEVEL RIDGE AXIS OUT WEST EDGES JUST A
BIT CLOSER TO THE CENTRAL U.S...AND MUCH DRYER AIR WILL BE IN PLACE
TO END THE WORK WEEK. OF COURSE...NW MIDLEVEL FLOW DOESNT ALWAYS
COOPERATE WITH THIS SCENARIO. DISREGARDED HUGE VORTICITY BULLSEYE
ROUNDING THE TOP OF THE RIDGE LATE FRI/SAT ON THE 00Z RUN OF THE
GFS...AND FOLLOWED THE ETA/META MORE CLOSELY FOR THIS FORECAST.

DSA

&&

.AVIATION...

ASSUMING WE AVOID ANY NORTHWEST FLOW SURPRISES VFR CONDITIONS
SHOULD BE THE RULE THROUGH AT LEAST THE NEXT 18 HOURS. THERE IS A
SMALL THREAT OF THUNDERSTORM DEVELOPMENT THIS AFTERNOON AND
EVENING...BUT GIVEN THE LIKELY ISOLATED NATURE OF ANY CONVECTION
HAVE OPTED TO NOT INCLUDE ANY THUNDER IN THE TAFS FOR NOW. ASSUMING
THAT SKIES ARE EXPECTED TO REMAIN GENERALLY CLEAR TONIGHT...THE DAY
CREW WILL NEED TO TAKE A LOOK AT BR/FG POSSIBILITIES FOR LATE
TONIGHT AT THE TERMINALS.

IZZI

&&

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

WFO SGF

KSZ073-097-101-MOZ055>058-066>071-077>083-088>098-101>106-061800-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SPRINGFIELD MO
935 AM CDT WED AUG 6 2003

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

.DAY ONE...TODAY AND TONIGHT.

  WEATHER HAZARDS EXPECTED:

  ISOLATED SEVERE THUNDERSTORMS POSSIBLE WITH...
    HAIL LARGER THAN NICKELS
    WIND GUSTS IN EXCESS OF 60 MPH
    HEAVY RAINFALL AND LOCALIZED MINOR FLOODING

  AREAS AFFECTED AND TIMING:

  THUNDERSTORMS ARE POSSIBLE ANYWHERE IN THE OUTLOOK
  AREA...PRIMARILY BETWEEN 3 PM AND 9 PM.  THE GREATEST
  POTENTIAL OF STORMS WILL BE EAST OF AN OSAGE BEACH TO
  BRANSON LINE.

  DISCUSSION:

  THERE IS A CHANCE FOR ISOLATED THUNDERSTORMS ACROSS THE OUTLOOK
  AREA TODAY. AT THIS TIME IT IS HARD TO DISTINGUISH ANY TRIGGER
  FOR THUNDERSTORM DEVELOPMENT...HOWEVER GIVEN THE DEGREE OF
  INSTABILITY AND THE STRONG WINDS ALOFT...ANY THUNDERSTORMS THAT DO
  DEVELOP WOULD LIKELY BECOME SEVERE WITH LARGE HAIL AND DAMAGING
  WINDS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

  UPPER LEVEL WINDS ARE FORECAST TO REMAIN NORTHWESTERLY DURING MUCH
  OF THE UPCOMING WEEK. THIS TYPE OF UPPER LEVEL PATTERN IS
  NOTORIOUS FOR PRODUCING WEAK DISTURBANCES THAT ARE DIFFICULT TO
  DETECT MORE THAN 24 HOURS IN ADVANCE. THESE DISTURBANCES ARE
  NOTORIOUS FOR PRODUCING THUNDERSTORMS...AND GIVEN THE DEGREE OF
  INSTABILITY AND THE STRONG WINDS ALOFT...IF ANY THUNDERSTORMS
  DEVELOP SEVERE WEATHER WOULD BE POSSIBLE. SO WHILE NO SEVERE
  WEATHER IS FORECAST AT THIS TIME...LATER FORECASTS SHOULD BE
  MONITORED.

.SPOTTER INFORMATION STATEMENT...

  DUE TO THE EXPECTED ISOLATED NATURE OF THE STORMS...SPOTTER
  ACTIVATION IS NOT EXPECTED AT THIS TIME. HOWEVER EMERGENCY
  MANAGERS AND SPOTTERS SHOULD MONITOR STORM DEVELOPMENT
  THIS AFTERNOON AND EVENING.

&&

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

FOSTER/IZZI