Severe Thunderstorm Warning 565, NWS Springfield, MO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
100 PM CDT THU OCT 16 2003

.DISCUSSION...
FORECAST CONCERNS: TIMING/AMOUNTS AND STRENGTH OF TONIGHTS SYSTEM.

VERY ORGANIZED SHORT WAVE OVER NORTH CENTRAL NEBRASKA HAS ALREADY
DEVELOPED AN EXPANDING AREA OF SHOWERS ACROSS SOUTHERN NEBRASKA
WHERE THE GREATEST MOISTURE ADVECTION AND UPPER LEVEL DIVERGENCE ARE
LOCATED. INITIALLY THE DEPTH OF THE MOISTURE IS LIMITED...HOWEVER
LATEST RUC INFO ALONG WITH AREA PROFILERS & SATELLITE PICTURES...
CONTINUE TO SHOW AN INCREASE IN MID LEVEL MOISTURE AHEAD OF THE
SHORT WAVE.

THIS IS VERY SIMILAR TO MONDAY NIGHTS SYSTEM WHICH TOOK THE HEAVIEST
PRECIPITATION NORTHEAST OF THE VORT MAX ACROSS NORTHERN
MISSOURI/CENTRAL ILLINOIS. ALSO...STRONG CYCLOGENESIS WILL OCCUR
OVER NORTHERN OKLAHOMA AND NORTHERN ARKANSAS THIS EVENING IN
RESPONSE OF THE TRACK AND STRENGTH OF VORT MAX MOVING SOUTHEASTWARD
INTO SOUTHWEST MISSOURI. BOTH THE GFS/ETA SHOW STRONG VERTICAL
MOTION (OMEGAS IN EXCESS OF 10 MB/S) OVER A LARGE AREA OF SOUTHERN
MISSOURI THIS EVENING. IN ADDITION...ATMOSPHERE SATURATES OVER A
LARGE VERTICAL COLUMN (BETWEEN 00-03Z). EVENING SHIFT WILL NEED TO
PAY CLOSE ATTENTION ON THE SPEED AND LOCATION OF THE VORT
MAX...ALONG WITH AREA PROFILERS TO SEE WHERE THE MAXIMUM LIFT
DEVELOPS. WILL LIKELY GO CATEGORICAL (WILL COORDINATE WITH
SURROUNDING OFFICES) FOR ALMOST ALL OF THE FORECAST AREA...EXCEPT IN
THE FAR SOUTHWEST WHERE UNCERTAINTY EXIST.

AS FOR WINDS...DEEPENING SURFACE LOW JUST SOUTH OF THE FORECAST
AREA...ALONG WITH STRONG COLD AIR ADVECTION OVER SOUTHERN
MISSOURI...INDICATES STRONG SURFACE WINDS. MESOETA 100-95H LAYER
WINDS INCREASE TO 20-30 KTS BETWEEN 03-06Z. @ 95-90H WINDS INCREASE
TO 35-45 KTS. LOCAL SOUNDINGS ALSO INDICATE ENOUGH MIXING AT LOW
LEVELS TO TRANSPORT SOME OF THE STRONGER WINDS TO THE SURFACE. HAVE
ALREADY UPDATED FOR WIND SPEEDS GUSTING TO 35 MPH OVERNIGHT. EVENING
SHIFT AVIATION/PUBLIC MAY NEED TO ADJUST WIND SPEEDS IF GREATER
MIXING DEVELOPS.

LONG TERM (FRIDAY THROUGH THURSDAY)...
NO MAJOR CHANGES AS THE SAME SCENARIO IS FORECAST. LARGE RIDGE
WILL BUILD OVER THE CENTRAL U.S. THIS WEEKEND. BY EARLY NEXT WEEK
THIS RIDGE WILL RETROGRADE OVER THE INTERMOUNTAIN WEST AND CAUSE A
DEEPENING TROUGH IN THE CENTRAL/EASTERN U.S. THIS MEANS COOLER THAN
NORMAL CONDITIONS BY MIDWEEK ALONG WITH DRY WEATHER.

JLT

&&

.AVIATION...
ALTHOUGH MID TO HIGH LEVEL CLOUDS WILL INCREASE THIS AFTERNOON...VFR
CONDITIONS WILL PREVAIL. CEILINGS WILL LOWER LATE THIS AFTERNOON AND
EVENING AS THE STRONG UPPER LEVEL SYSTEM APPROACHES THE AREA.
PRECIPITATION ALONG WITH MVFR CEILINGS AND VISIBILITIES WILL DEVELOP
THIS EVENING. A DEEPENING LOW PRESSURE SYSTEM WILL LEAD TO GUSTY
WINDS IN THE WAKE OF THE STORM SYSTEM LATE TONIGHT. WIND GUSTS UP TO
30 KTS AT THE SURFACE WILL BE POSSIBLE. A STRATUS OR STRATOCUMULUS
DECK MAY SPREAD ACROSS THE AREA AFTER MIDNIGHT. CEILINGS WILL LIKELY
REMAIN MAINLY IN THE MVFR RANGE...BUT LOCAL IFR CEILINGS WILL BE
POSSIBLE. VFR CONDITIONS WILL RETURN FRIDAY.

FOSTER

&&

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

WFO SGF

KSZ073-097-101-MOZ055>058-066>071-077>083-088>098-101>106-171100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SPRINGFIELD MO
115 PM CDT THU OCT 16 2003

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

.DAY ONE...THIS AFTERNOON AND TONIGHT.

  WEATHER HAZARDS EXPECTED:

SCATTERED THUNDERSTORMS...WITH ISOLATED STRONG STORMS POSSIBLE. THE
STRONGEST STORMS WILL BE CAPABLE OF PRODUCING ONE HALF INCH HAIL AND
GUSTY WINDS OF 35 TO 45 MPH.

SUSTAINED WINDS OF 25 TO 35 MPH WILL HIGHER GUSTS BEHIND FRONTAL
PASSAGE THIS EVENING.

  AREAS AFFECTED AND TIMING:

AFTER 4 PM OVER WESTERN MISSOURI AND SOUTHEAST KANSAS...BETWEEN 6
AND 9 PM OVER THE REST OF THE MISSOURI OZARKS. SHOWERS AND
THUNDERSTORMS WILL TAPER OFF RAPIDLY FROM WEST TO EAST LATE THIS
EVENING AND OVERNIGHT...ENDING IN THE WEST PLAINS AREA BY 2 AM.

  DISCUSSION:

A STRONG BUT FAST MOVING UPPER LEVEL STORM SYSTEM WILL MOVE
SOUTHEAST FROM THE NORTHERN ROCKIES AND THROUGH CENTRAL AND SOUTHERN
MISSOURI OVERNIGHT. SOUTH WINDS IN THE LOWER LEVELS WILL TRANSPORT
MOISTURE QUICKLY NORTHWARD THIS AFTERNOON IN ADVANCE OF THIS SYSTEM.
A STRONG UPPER LEVEL JET STREAM WILL ALSO PROVIDE FAVORABLE WINDS
ALOFT TO SUPPORT ORGANIZED THUNDERSTORMS...SOME OF WHICH COULD BE
LOCALLY STRONG. THE LIMITATION OF ANY SEVERE WEATHER WILL BE THE
ELEVATED NATURE OF THE THUNDERSTORMS. THE STORM SYSTEM WILL QUICKLY
EXIT THE REGION OVERNIGHT. IN ADDITION TO THE THUNDERSTORMS...A
STRONG PRESSURE GRADIENT WILL DEVELOP THIS EVENING WHICH WILL
PROVIDE STRONG SURFACE WINDS OF 25 TO 35 MPH...WITH OCCASIONAL
HIGHER GUSTS. THE OZARK PLATEAU WILL HAVE THE HIGHEST WIND SPEEDS
DUE TO THE TERRAIN EFFECT.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED TO BE NEEDED THROUGH TONIGHT.

&&

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

JLT/DSA