[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 110608
SWODY2
SPC AC 110607

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1207 AM CST SAT MAR 11 2006

VALID 121200Z - 131200Z

...THERE IS A MDT RISK OF SVR TSTMS SUN AFT/EVE ACROSS MUCH OF THE
MIDDLE MISSISSIPPI  VALLEY...FOR A POSSIBLE OUTBREAK OF SEVERE
STORMS...INCLUDING SUPERCELLS WITH POTENTIAL FOR ISOLATED STRONG
TORNADOES....

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MODERATE RISK
AREA...FROM EASTERN PORTIONS OF THE CNTRL/SRN PLAINS THRU THE OHIO
VALLEY....

SEVERAL SIGNIFICANT SHORT WAVE IMPULSES CONTINUE TO PROGRESS THROUGH
A BROAD/DEEP COLD UPPER TROUGH...WHICH NOW ENCOMPASSES MUCH OF THE
WESTERN AND CENTRAL STATES.  STRONGEST OF THESE IMPULSES/JET STREAKS
NOW APPEARS TO BE DIGGING INTO BASE OF UPPER TROUGH NEAR THE
SOUTHERN CALIFORNIA COAST...AND IS STILL PROGGED BY MOST MODEL
GUIDANCE TO NOSE INTO THE SOUTHERN ROCKIES BY 12Z SUNDAY.

MODELS SUGGEST THIS FEATURE WILL CONTINUE TO LIFT OUT...ACROSS THE
CENTRAL PLAINS AND MIDDLE MISSISSIPPI VALLEY...SUNDAY/SUNDAY NIGHT. 
THIS IS PROGGED TO OCCUR IN PHASE WITH A STRONG SUBTROPICAL JET
STREAK...WHICH IS EXPECTED TO NOSE ACROSS THE SOUTHERN PLAINS AND
LOWER MISSISSIPPI VALLEY...AND BULK OF UPPER TROUGH IS FORECAST TO
BEGIN LIFTING OUT OF THE WESTERN STATES.

VARIABILITY STILL EXISTS AMONG SOME MODELS CONCERNING THE STRENGTH
OF SURFACE CYCLOGENESIS TO OCCUR IN THE LEE OF THE CENTRAL ROCKIES. 
HOWEVER...WHILE MOST SUBSTANTIAL DEEPENING MAY NOT OCCUR UNTIL
MONDAY ACROSS THE EASTERN CANADIAN PROVINCES...IT NOW APPEARS MOST
LIKELY THAT A SUB 1000 MB SURFACE LOW WILL DEVELOP BY EARLY SUNDAY
ACROSS THE CENTRAL HIGH PLAINS...BEFORE TRACKING NORTHEASTWARD INTO
THE GREAT LAKES REGION BY 12Z MONDAY.

REGARDLESS...WITH 70F+ DEW POINTS NOW PRESENT ACROSS MUCH OF THE
GULF OF MEXICO...AND A SIGNIFICANT RETURN FLOW ALREADY UNDERWAY INTO
THE SOUTHERN PLAINS/LOWER MISSISSIPPI VALLEY...A BROAD VERY MOIST
AND POTENTIALLY MODERATELY UNSTABLE WARM SECTOR IS EXPECTED ACROSS
THE CENTRAL STATES BY SUNDAY AFTERNOON.  AS FLOW FIELDS STRENGTHEN
AND VERTICAL SHEAR PROFILES INCREASE WITHIN THIS WARM SECTOR...THE
ENVIRONMENT IS EXPECTED TO BECOME SUPPORTIVE OF AN OUTBREAK OF
SEVERE STORMS WITH LARGE HAIL/WIND DAMAGE AND TORNADOES.  RISK AREA
WILL INCLUDE METROPOLITAN KANSAS CITY/ST. LOUIS AND LITTLE ROCK LATE
SUNDAY AFTERNOON...EXTENDING EASTWARD INTO INDIANAPOLIS/MEMPHIS
SUNDAY EVENING...POSSIBLY THE LOUISVILLE/CINCINNATI AND CLEVELAND
AREAS SUNDAY NIGHT.

...EAST CENTRAL PLAINS THROUGH THE MIDDLE MISSISSIPPI VALLEY...
WHILE CONSIDERABLE CONVECTION ASSOCIATED WITH A LEAD SHORT WAVE
IMPULSE MAY BE ONGOING AT 12Z SUNDAY ACROSS THE LOWER OHIO VALLEY
...MUCH OF THE EAST CENTRAL PLAINS AND MIDDLE MISSISSIPPI VALLEY IS
EXPECTED TO BE RELATIVE FREE OF CONVECTION/PRECIPITATION.  WITH
INSOLATION...STEEP MID-LEVEL LAPSE RATES ON NOSE OF RETURNING
ELEVATED MIXED LAYER...AND SURFACE DEW POINTS IN THE 60S...SHOULD
CONTRIBUTE TO MIXED LAYER CAPE ON THE ORDER OF 2000 J/KG IN SURFACE
WARM SECTOR.  THIS WILL EXIST EAST OF DRY LINE...LIKELY TO TRAIL
SOUTH OF SURFACE LOW CENTER ACROSS NORTHEAST KANSAS BY LATE
AFTERNOON...AND SOUTH OF WARM FRONT...LIKELY TO EXTEND EAST OF LOW
INTO THE LOWER GREAT LAKES REGION.

THOUGH DETAILS OF SURFACE FEATURES ARE STILL UNCERTAIN...CAPPING
WITHIN WARM SECTOR SEEMS LIKELY TO BE WEAK ENOUGH FOR SCATTERED
CONVECTIVE DEVELOPMENT IN RESPONSE TO FORCING ASSOCIATED WITH PEAK
HEATING/BROAD LOW-LEVEL WARM ADVECTION AND DIFLUENT UPPER FLOW
REGIME.  SUPERCELLS COULD BECOME FAIRLY NUMEROUS BY LATE SUNDAY
AFTERNOON...PARTICULARLY FROM PARTS OF EASTERN KANSAS THROUGH
MISSOURI AND MUCH OF ARKANSAS. 30 TO 50 KT SOUTHERLY LOW-LEVEL JET
ACROSS THIS REGION WILL CONTRIBUTE TO LARGE LOW-LEVEL HODOGRAPHS
BENEATH STRONG WEST SOUTHWESTERLY UPPER FLOW.  A FEW TORNADOES
APPEAR LIKELY...SOME OF WHICH COULD BECOME STRONG.
OTHERWISE...LARGE HAIL/DAMAGING WIND GUSTS WILL ALSO ACCOMPANY
STRONGER STORMS...WHICH SHOULD DEVELOP INTO ILLINOIS EARLY SUNDAY
EVENING.

...OHIO VALLEY...
INTENSIFYING SOUTHERLY LOW-LEVEL JET AND FORCING ASSOCIATED WITH
PRIMARY UPPER IMPULSE...EAST SOUTHEAST OF SURFACE LOW...ARE EXPECTED
TO SUPPORT ORGANIZING SQUALL LINE SUNDAY EVENING ACROSS PARTS OF THE
SOUTHERN GREAT LAKES REGION AND LOWER OHIO VALLEY.  ACTIVITY WILL
CONTINUE EASTWARD THROUGH MUCH OF THE REMAINDER OF THE OHIO VALLEY
SUNDAY NIGHT/EARLY MONDAY...WITHIN 50+ KT MEAN FLOW REGIME.  THIS
WILL SUPPORT CONTINUING SEVERE POTENTIAL... PRIMARILY IN THE FORM OF
DAMAGING WINDS.

..KERR.. 03/11/2006