Hail in Kansas, December 9, 2003

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
255 AM CST TUE DEC 9 2003

...FIRST WINTER STORM OF THE SEASON ON THE WAY...

.DISCUSSION...
WATER VAPOR IMAGERY CLEARLY DEPICTS A STRONG SHORTWAVE TROUGH
SLIDING ACROSS NEW MEXICO EARLY TUESDAY. SCATTERED SHOWERS AND A FEW
THUNDERSTORMS HAD DEVELOP ACROSS THE OZARKS REGION IN AREA OF
INCREASING WARM AIR ADVECTION. PRECIPITATION WAS ALSO INCREASING
FARTHER WEST IN AN INCREASINGLY DIFFLUENT PATTERN AHEAD OF THE
DEEPENING TROUGH. SURFACE ANALYSIS SHOWED A WARM FRONT JUST NORTH OF
THE ARKANSAS BORDER WITH WARM SECTOR DEWPOINTS IN THE UPPER 50S UP
INTO EASTERN OKLAHOMA.

SHORT TERM (TODAY THROUGH WEDNESDAY)...
MODELS HAVE COME INTO REASONABLE AGREEMENT ON THE EVOLUTION AND
TRACK OF THE APPROACHING STORM SYSTEM. THE GFS REMAINS THE MOST
CONSISTENT OVER THE PAST FEW MODEL RUNS.

SHOWERS AND THUNDERSTORMS ARE EXPECTED TO INCREASE THROUGH THE
MORNING AS A 40-50KT LOW LEVEL JET RESULTS IN STRONG WARM AIR
ADVECTION AND RAPID MOISTURE TRANSPORT. INCREASING UPPER LEVEL
DIFFLUENCE WILL AID DEVELOPMENT TODAY AS THE POTENT SHORTWAVE
BECOMES NEGATIVE TILT AND MAKES ITS WAY ACROSS THE SOUTHERN PLAINS.
A SHARP COLD FRONT WILL DEVELOP AS STRONG COLD AIR ADVECTION
DEVELOPS IN THE WAKE OF THE DEEPENING SURFACE LOW. STRONG
FRONTOGENETICAL FORCING ALONG THE FRONT AIDED BY A 70KT MID LEVEL
JET STREAK WILL SUPPORT CONVECTION AND THE DEVELOPMENT OF A SQUALL
LINE ALONG THE FRONT BY EARLY AFTERNOON. SURFACE INSTABILITY WILL BE
LIMITED DUE TO CLOUD COVER AND PRECIPITATION BUT AMPLE FORCING WILL
COMPENSATE TO SUPPORT THUNDERSTORM DEVELOPMENT. STRONG TO SEVERE
STORMS WILL BE POSSIBLE.  THE PRIMARY THREAT WILL BE LARGE HAIL AS
LAPSE RATES STEEPEN AND FREEZING LEVELS LOWER. DAMAGING WIND GUSTS
WILL BE POSSIBLE ACROSS FAR SOUTHERN MISSOURI WHERE SURFACE
DEWPOINTS MAY RISE INTO THE UPPER 50S. 06Z MESO-ETA HAS TRENDED
FARTHER NORTH WITH THE SURFACE LOW TRACK WHICH WOULD SUPPORT THE
DEVELOPMENT OF A SQUALL LINE FARTHER NORTH INTO THE SOUTHERN
MISSOURI. LATEST MESO-ETA ALSO SHOWS SURFACE BASED CAPES NEAR 400
J/KG SOUTH OF THE SURFACE LOW AND 0-6KM SHEAR MAGNITUDE APPROACHING
70 KTS. SEVERE WEATHER POTENTIAL WILL HAVE TO BE CLOSELY MONITORED.

STRONG COLD AIR ADVECTION WILL FOLLOW THE FRONTAL PASSAGE THIS
EVENING AS THE SURFACE LOW TRACKS INTO EAST CENTRAL MISSOURI.
HIGHEST ACCUMULATIONS AND MOST PERSISTENT SNOW WILL FALL NORTHWEST
OF THE AREA WHERE TROUGH OF WARM AIR ALOFT (TROWAL) DEVELOPS.
HOWEVER THE TROWAL WILL WRAP AROUND THE TIGHTLY CLOSED AND NEARLY
STACKED LOW AS DEPICTED ON THE 295-305K THETA SURFACES AND THETA-E
FIELD AT 700 MB. FORECAST SOUNDINGS SUGGEST A RAPID TRANSITION OVER
TO SNOW FROM WEST TO EAST AS THE UPPER LOW CENTER TRACKS ACROSS THE
OZARKS. STRONG VERTICAL VELOCITIES WILL LIKELY RESULT IN A BURST OF
MODERATE TO HEAVY SNOW ALONG AND NORTHWEST OF THE UPPER LOW TRACK.
THE TRACK OF THE MID AND UPPER LEVEL LOW AND ASSOCIATED HEIGHT FALLS
SUGGEST ACCUMULATING SNOW WILL MAINLY AFFECT THE NORTHWESTERN HALF
OF THE FORECAST AREA OR NORTHWEST OF A CASSVILLE TO VIENNA LINE. I
WILL ISSUE A WINTER WEATHER ADVISORY FOR THIS AREA TONIGHT AND EARLY
WEDNESDAY. ACCUMULATIONS WILL BE LIMITED TO THE RELATIVELY SHORT
DURATION BUT A QUICK 1 TO 3 INCHES WILL BE POSSIBLE WITH LOCALLY
HIGHER ACCUMULATIONS NEAR 4 INCHES.

SNOW WILL TAPER OFF TO FLURRIES FROM WEST TO EAST WEDNESDAY MORNING.
TEMPERATURES WILL STRUGGLE TO RISE DUE TO COLD AIR ADVECTION AND
SNOW COVER.

LONG TERM (THURSDAY THROUGH MONDAY)...
PROGRESSIVE AND ACTIVE PATTERN WILL CONTINUE INTO THE WEEKEND. THE
GFS NOW BRINGS PRECIPITATION INTO THE AREA BY FRIDAY NIGHT. WILL
EXPAND THE CHANCE OF MIXED PRECIPITATION FOR ALL OF SATURDAY BUT
WILL NOT INTRODUCE PRECIPITATION YET FOR FRIDAY NIGHT.

FOSTER

.AVIATION...
LOW LEVEL JET PROVIDING 40 KNOTS OF SWRLY FLOW AROUND 2000 FEET WILL
BE PRIMARY CONCERN THROUGH DAYBREAK. HAVE AMENDED TAFS TO ADD LOW
LEVEL WIND SHEAR. MVFR VIS WIDESPREAD NOW AS SHOWERS DURING THE
EVENING HOURS ATTEMPT TO EVAPORATE INTO AN INCREASINGLY SATURATED
AIRMASS. DO NOT EXPECT MUCH IMPROVEMENT. CIGS WILL CONTINUE TO LOWER
THROUGH THE PERIOD AS MOISTURE ADVECTION CONTINUES IN EARNEST...
ALTHOUGH SHOULD REMAIN GENERALLY MVFR THROUGH THE DAY.

OTHERWISE...SHOWERS AND THUNDERSTORMS WILL GRADUALLY INCREASE IN
COVERAGE THROUGHOUT THE DAY. THUNDERSTORMS WITH FREQUENT
LIGHTNING...DAMAGING WIND GUSTS AND LARGE HAIL MAY DEVELOP OVER
CENTRAL AND SOUTH CENTRAL MISSOURI AFTER 18Z CONTINUING THROUGH
AROUND 03Z BEFORE EXITING EAST OF THE FORECAST AREA.

SHARP WIND SHIFT FROM SOUTH TO NORTHWEST WILL ACCOMPANY FRONTAL
PASSAGE THIS EVENING...WITH QUICK CHANGEOVER FROM RAIN TO SNOW
BETWEEN 9 PM AND 3 AM. THERE MAY BE SOME HEAVIER BURSTS OF SNOW THAT
LIMIT THE VISIBILITY TO UNDER A MILE DURING THAT TIME FRAME.

BOOKBINDER

&&

.SGF WATCHES/WARNINGS/ADVISORIES...
MO...WINTER WEATHER ADVISORY NORTHWEST OF A CASSVILLE TO VIENNA LINE
TONIGHT AND WEDNESDAY MORNING.

KS...WINTER WEATHER ADVISORY FOR EXTREME SOUTHEAST KANSAS TONIGHT
AND EARLY WEDNESDAY.

WFO SGF

HAZARDOUS WEATHER OUTLOOK...RETRANSMITTED
NATIONAL WEATHER SERVICE SPRINGFIELD MO
600 AM CST TUE DEC 9 2003

KSZ073-097-101-MOZ055>058-066>071-077>083-088>098-101>106-091900-
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.
600 AM CST TUE DEC 9 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 WITH LARGE HAIL UP TO THE SIZE OF
  NICKELS AND DAMAGING WINDS IN EXCESS OF 60 MPH.

  LOCALLY HEAVY RAINFALL AMOUNTS OF 1 TO 2 INCHES AND LOCALIZED
  FLOODING.

  SNOW ACCUMULATIONS OF 1 TO 4 INCHES.

  AREAS AFFECTED AND TIMING:

  SCATTERED THUNDERSTORMS AND LOCALLY HEAVY RAINFALL WILL AFFECT THE
  OZARKS REGION TODAY.  THE PRIMARY RISK OF SEVERE THUNDERSTORMS
  WILL OCCUR ACROSS FAR SOUTHERN MISSOURI OR SOUTH OF INTERSTATE 44.

  ACCUMULATING SNOW WILL AFFECT SOUTHEAST KANSAS AND MUCH OF
  SOUTHWEST MISSOURI TONIGHT.

  DISCUSSION:

  A POWERFUL STORM SYSTEM WILL PUSH ACROSS THE SOUTHERN PLAINS TODAY
  AND INTO THE OZARKS REGION TONIGHT. THUNDERSTORMS WILL DEVELOP
  TODAY AHEAD OF A DEEPENING LOW PRESSURE SYSTEM AND ASSOCIATED COLD
  FRONT. DESPITE THE CLOUD COVER...AMPLE INSTABILITY AND MOISTURE
  ALONG WITH FAVORABLE WIND FIELD IN THE LOWER ATMOSPHERE WILL
  SUPPORT THUNDERSTORM DEVELOPMENT. A SQUALL LINE WILL LIKELY FORM
  ALONG THE COLD FRONT AND EXTEND AS FAR NORTH AS FAR SOUTHERN
  MISSOURI THIS AFTERNOON. ISOLATED SEVERE THUNDERSTORMS WILL BE
  POSSIBLE. GIVEN THE STRENGTH OF THE APPROACHING SYSTEM AND
  ASSOCIATED WIND FIELD ANY INCREASE IN STABILITY COULD RESULT IN A
  HIGHER POTENTIAL FOR SEVERE THUNDERSTORMS. EMERGENCY MANAGERS AND
  SPOTTERS SHOULD STAYED TUNED TO THE LATEST WEATHER INFORMATION
  TODAY.

  THE RAIN WILL RAPIDLY CHANGE TO SNOW TONIGHT FROM WEST TO EAST AS
  THE STORM SYSTEM LIFTS NORTHEAST.  A RAPID ONSET OF MODERATE TO
  HEAVY SNOW IS EXPECTED WITH ACCUMULATIONS OF 1 TO 3 INCHES LIKELY.
  LOCALLY HIGHER AMOUNTS NEAR 4 INCHES WILL BE POSSIBLE FROM
  SOUTHEAST KANSAS INTO CENTRAL MISSOURI.

  ADDITIONAL INFORMATION:

  A WINTER WEATHER ADVISORY IS IN EFFECT TONIGHT AND EARLY WEDNESDAY
  FOR AREAS NORTHWEST OF A LINE FROM CASSVILLE...TO MARSHFIELD...TO
  VIENNA.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

  THE SNOW WILL TAPER OFF TO FLURRIES EARLY WEDNESDAY BUT HAZARDOUS
  TRAVEL CONDITIONS WILL BE POSSIBLE WEDNESDAY MORNING.

  ANOTHER STORM SYSTEM MAY BRING ACCUMULATING SNOW TO THE REGION
  THIS WEEKEND. THE DEVELOPMENT OF THIS SYSTEM AND POSSIBLE SNOW
  ACCUMULATIONS REMAINS UNCERTAIN.  STAY TUNED TO THE LATEST
  FORECASTS ON THE POTENTIAL OF MORE WINTER WEATHER THIS WEEKEND.

.SPOTTER INFORMATION STATEMENT...

  SPOTTER ACTIVATION MAY BE REQUIRED TODAY FOR AREAS MAINLY SOUTH OF
  INTERSTATE 44.

FOSTER