SPC AC 060600
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT THU SEP 06 2012
VALID 071200Z - 081200Z
...THERE IS A SLGT RISK OF SVR TSTMS MID AND LOWER OH/MID MS VALLEYS
SWWD INTO THE OZARKS...
...SYNOPSIS...
THE SYNOPTIC-SCALE ENVIRONMENT IS FORECAST TO UNDERGO STRENGTHENING
THIS PERIOD...AS A ROBUST UPPER SHORT-WAVE TROUGH DIGS SEWD OUT OF
THE PLAINS/UPPER MS VALLEY REGION AND INTO THE MID MS/OH VALLEYS.
AS THIS OCCURS...A COLD FRONT -- INITIALLY STRETCHING FROM THE UPPER
GREAT LAKES REGION SWWD ACROSS THE TX PANHANDLE -- WILL STRENGTHEN
WHILE SHIFTING RAPIDLY EWD/SEWD WITH TIME. BY LATE IN THE
PERIOD...THIS FRONT SHOULD EXTEND FROM THE LOWER GREAT LAKES REGION
SWWD ACROSS THE TN/LOWER MS VALLEYS. THIS STORM SYSTEM SHOULD FOCUS
A BROAD AREA OF ACTIVE/LOCALLY-SEVERE STORMS -- MAINLY FROM
AFTERNOON THROUGH LATE EVENING.
...MID AND LOWER OH/MID MS VALLEYS AND THE OZARKS REGION...
SHOWERS AND THUNDERSTORMS SHOULD BE ONGOING AT THE START OF THE
PERIOD ACROSS PARTS OF KS/MO AND VICINITY...WITHIN ZONE OF STRONG QG
FORCING AHEAD OF THE SURFACE COLD FRONT. AS THE UPPER TROUGH DIGS
SEWD AND THE COLD FRONT SHARPENS/ADVANCES ACROSS THE MID MS/OH
VALLEYS AND OZARKS INTO THE AFTERNOON HOURS...A DESTABILIZING
ENVIRONMENT SHOULD SUPPORT AN INCREASE/REDEVELOPMENT OF STORMS.
WITH STRONGER FLOW ALOFT ROTATING AROUND THE BASE OF THE TROUGH AND
ATOP THE WARM SECTOR...SHEAR WILL BECOME SUPPORTIVE OF
ORGANIZED/SEVERE STORMS -- WITH DAMAGING WINDS EXPECTED TO BECOME
THE PRIMARY THREAT ALONG WITH SOME HAIL. WHILE THE DETAILS
REGARDING EVOLUTION OF THIS CONVECTIVE THREAT THROUGH THE AFTERNOON
AND INTO THE EVENING ARE SOMEWHAT DIFFICULT TO DISCERN DUE TO THE
DYNAMIC/STRENGTHENING SYNOPTIC-SCALE ENVIRONMENT DURING THE
PERIOD...WILL INTRODUCE A FAIRLY LARGE SLIGHT RISK AREA FROM THE
OZARKS NEWD INTO THE MID OH VALLEY AREA TO COVER THIS EVOLVING
SEVERE WEATHER SCENARIO.
...PARTS OF THE LOWER GREAT LAKES REGION...
SCATTERED SHOWERS AND THUNDERSTORMS SHOULD EVOLVE THROUGH THE DAY
ACROSS THE LOWER GREAT LAKES/UPPER OH VALLEY REGION DAY 2...AS
AFTERNOON AIRMASS DESTABILIZATION PUSHES MIXED-LAYER CAPE VALUES
INTO THE 1000 TO 1500 J/KG RANGE IN MOST AREAS. WITH A LACK OF A
CLEAR LOW-LEVEL FOCUSING MECHANISM DURING THE DAY AND MODEST FLOW
ALOFT...ONLY A VERY ISOLATED WIND/HAIL THREAT IS EVIDENT THROUGH THE
FIRST HALF OF THE PERIOD.
OVERNIGHT...AS THE COLD FRONT APPROACHES FROM THE WEST...STORMS MAY
BECOME MORE NUMEROUS ALONG THIS BOUNDARY. FLOW ALOFT WILL INCREASE
THROUGH THE EVENING AND INTO THE OVERNIGHT HOURS AS WELL...BUT WITH
THIS OCCURRING DURING THE DIURNALLY LESS FAVORABLE THERMODYNAMIC
ENVIRONMENT...SEVERE THREAT SHOULD REMAIN LIMITED AFTER DARK --
PRIMARILY IN THE FORM OF ISOLATED GUSTY WINDS.
..GOSS.. 09/06/2012
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z
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