Tornado and Flash Flooding in Missouri, October 12 to 14, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
156 AM CDT FRI OCT 12 2012

.DISCUSSION...

AN ACTIVE WEATHER PERIOD IS AMONGST US OVER EXTREME SOUTHEAST KANSAS
AND THE MISSOURI OZARKS. SCATTERED SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED ACROSS THE REGION EARLY THIS MORNING...IN RESPONSE TO LOW
LEVEL JET ACTION IMPINGING INTO AN EAST TO WEST ZONE OF
BAROCLINICITY.

WE'RE THINKING SOME OF THESE STORMS WILL LIKELY GO SEVERE AS WE
ADVANCE INTO THE FRIDAY MORNING HOURS.  THE 00Z RAOB FROM LAST
NIGHT...MEASURED 1703 J/KG OF CAPE FROM AN 850 MB PARCEL.  THIS IS A
LOT MORE CAPE THAN ANY OF THE MODELS HAD FORECASTED.  WE THINK ONCE
THIS PARCEL BECOMES MORE REALIZED THIS MORNING WITH INCREASED
ISENTROPIC LIFT...HAIL GENERATION WILL BEGIN.  RIGHT NOW WE THINK
HAIL TO THE SIZE OF QUARTERS WILL OCCUR WITH SOME OF THE STRONGER
STORMS.

AS THE LOW LEVEL JET WEAKENS TOWARD MID MORNING...STORM FREQUENCY
WILL START TO DECREASE...LEAVING MOST LOCATIONS ACROSS THE REGION
WITH DRY CONDITIONS INTO FRIDAY AFTERNOON AND EVENING. THIS WINDOW
OF DRY WEATHER WILL CONTINUE INTO SATURDAY MORNING...AND POSSIBLY
EARLY SATURDAY AFTERNOON.

THE NATIONAL WEATHER SERVICE IN SPRINGFIELD IS PREPARING FOR A
MODERATE EPISODE OF SEVERE WEATHER LATE SATURDAY AFTERNOON INTO
SATURDAY NIGHT.  DAMAGING WIND GUSTS UP TO 75 MPH IS EXPECTED WITH
THE STRONGER STORMS.

WE CAN NOT RULE OUT A TORNADO OR TWO...ESPECIALLY WITH ANY LINE
SEGMENTS THAT BECOME ORGANIZED.  GIVEN THE STRUCTURE AND MAGNITUDE
OF 0-3 KM SHEAR...ERECT AND EVEN FORWARD LEANING UPDRAFTS WITHIN LINE
SEGMENTS OR A SQUALL LINE ARE EXPECTED.  THIS EXPECTATION...ALONG
WITH MODEST VALUES OF LOW LEVEL CAPE...WILL POSE A RISK FOR A COUPLE
OF SQUALL LINE TORNADOES. THE BETTER STORMS SHOULD OCCUR OVER
EXTREME SOUTHEAST KANSAS AND FAR WESTERN MISSOURI.  HOWEVER...SEVERE
RISKS WILL OCCUR AS FAR EAST AS THE HIGHWAY 63 CORRIDOR.

STORMS WILL EXIT THE OZARKS BY SUNDAY MORNING...GIVING WAY TO A
STABLE PACIFIC AIRMASS.  THEREFORE WE'RE NOT EXPECTING A WHOLE LOT
OF COLD AIR BEHIND SATURDAY NIGHTS FRONTAL PASSAGE.  THIS CHANGE IN
AIRMASS WILL PROVIDE FOR A DRY FORECAST SUNDAY THROUGH TUESDAY.

TEMPERATURES DURING THE SUNDAY THROUGH TUESDAY TIME FRAME WILL STAY
MILD...WITH AFTERNOON HIGHS WELL INTO THE 70S...AND OVERNIGHT LOWS
IN THE 50S. SOUTHERLY WINDS WILL ALLOW GULF MOISTURE TO QUICKLY
RETURN TO THE OZARKS.

THIS INCREASE IN MOISTURE WILL SET THE STAGE FOR ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS BY WEDNESDAY.  MODELS SUGGEST THAT A
PHASED TROUGH WILL APPROACH FROM THE WEST...DRAGGING ANOTHER PACIFIC
FRONT THROUGH SOUTHERN MISSOURI.  EARLY MODEL INDICATIONS SUGGEST
THAT INSTABILITY LEVELS WILL NOT BECOME SUFFICIENT FOR SEVERE
WEATHER ON WEDNESDAY.  THEREFORE AT THIS TIME...WE WILL NOT BE
MENTIONING A RISK FOR SEVERE STORMS IN THE HWO FOR WEDNESDAY.

CRAMER

&&

.AVIATION...

SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP OVERNIGHT
AS A COLD FRONT PUSHES IN FROM THE NORTHWEST. MVFR IS EXPECTED TO
PREVAIL ONCE STORMS DEVELOP. THERE MAY ALSO BE POCKETS OF IFR AND
PERHAPS SOME HAIL WITH STRONGER STORMS. IFR CEILINGS ARE THEN
EXPECTED TO DEVELOP BEHIND THE COLD FRONT LATE TONIGHT AND EARLY
FRIDAY MORNING. WINDS WILL SHIFT TO THE EAST AND NORTHEAST BEHIND THE
FRONT. FLIGHT CONDITIONS ARE THEN EXPECTED TO IMPROVE INTO THE
MVFR CATEGORY BY FRIDAY AFTERNOON... ALTHOUGH EXACT TIMING OF THE
IFR TO MVFR TRANSITION IS STILL UNCERTAIN. MODELS ARE THEN
HINTING AT IFR CEILINGS DEVELOPING LATE FRIDAY EVENING ALONG WITH
LOW LEVEL WIND SHEAR.

SCHAUMANN

&&

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SPRINGFIELD MO
350 AM CDT FRI OCT 12 2012

KSZ073-097-101-MOZ055>058-066>071-077>083-088>098-101>106-130900-
BOURBON-CRAWFORD-CHEROKEE-BENTON-MORGAN-MILLER-MARIES-VERNON-
ST. CLAIR-HICKORY-CAMDEN-PULASKI-PHELPS-BARTON-CEDAR-POLK-DALLAS-
LACLEDE-TEXAS-DENT-JASPER-DADE-GREENE-WEBSTER-WRIGHT-NEWTON-
LAWRENCE-CHRISTIAN-DOUGLAS-HOWELL-SHANNON-MCDONALD-BARRY-STONE-
TANEY-OZARK-OREGON-
350 AM CDT FRI OCT 12 2012

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

.DAY ONE...TODAY AND TONIGHT.

WEATHER HAZARDS EXPECTED...

  LIMITED HAIL RISK.
  SIGNIFICANT LIGHTNING RISK.
  LIMITED FLOOD RISK.

DISCUSSION...

  MARGINALLY SEVERE THUNDERSTORMS ARE POSSIBLE THIS MORNING.
  THESE STORMS WILL BE CONFINED TO AREAS ALONG AND SOUTH OF A LINE
  FROM GIRARD KANSAS...TO SPRINGFIELD MISSOURI. LARGE HAIL UP TO
  THE SIZE OF QUARTERS WILL BE THE PRIMARY HAZARD WITH THESE STORMS.
  LOCALIZED HEAVY RAIN WILL OCCUR IN SOME AREAS...POSING A LIMITED
  FLOOD RISK.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

  AN EPISODE OF SEVERE THUNDERSTORMS WILL OCCUR LATE SATURDAY
  AFTERNOON INTO SATURDAY NIGHT OVER AREAS OF EXTREME SOUTHEAST
  KANSAS AND THE MISSOURI OZARKS. DAMAGING WIND GUSTS UP TO 75 MPH
  WILL BE THE PRIMARY RISK WITH THESE STORMS. A TORNADO OR TWO CAN
  NOT BE RULED OUT.

.SPOTTER INFORMATION STATEMENT...

  SPOTTER ACTIVATION MAY BE NEEDED IN THE NEXT THREE HOURS FOR
  AREAS ALONG AND SOUTH OF A LINE FROM GIRARD KANSAS TO
  SPRINGFIELD MISSOURI.

&&

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

CRAMER