DAY2SVR: Nws Storm Prediction Center Norman Ok

ACUS02 KWNS 091731
SWODY2
SPC AC 091730

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1230 PM CDT SAT JUN 09 2012

VALID 101200Z - 111200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE UPPER MS
VALLEY...MID-MO VALLEY AND GREAT PLAINS...

...UPPER MS VALLEY/MID-MO VALLEY/CNTRL AND SRN PLAINS...
AN UPPER-LEVEL TROUGH WILL PROGRESS EWD ACROSS THE NRN HIGH PLAINS
SUNDAY AS A MID-LEVEL JET MOVES NEWD ACROSS THE DAKOTAS. AT THE
SFC...A COLD FRONT WILL ADVANCE EWD ACROSS THE NRN PLAINS WITH
THUNDERSTORMS DEVELOPING ALONG THE BOUNDARY DURING THE DAY. STRONG
LARGE-SCALE ASCENT ASSOCIATED WITH THE APPROACHING SYSTEM AND LIFT
ALONG THE FRONT SHOULD SUPPORT AN ELEVATED CONVECTIVE CLUSTER
ONGOING IN THE DAKOTAS SUNDAY MORNING. THIS CONVECTIVE COMPLEX IS
FORECAST TO MOVE NEWD INTO ERN ND AND NW MN BY MIDDAY AND MAY BE
ACCOMPANIED BY A MARGINAL SEVERE THREAT. TO THE SOUTHEAST OF THIS
ACTIVITY...MODEL FORECASTS DEVELOP A CORRIDOR OF MODERATE TO STRONG
INSTABILITY BY MID-AFTERNOON EXTENDING FROM THE MID-MO VALLEY NNEWD
INTO IA AND MN ALONG WHICH THUNDERSTORMS SHOULD INITIATE DURING THE
LATE AFTERNOON. CONVECTIVE COVERAGE SHOULD INCREASE DURING THE
EVENING WITH STORMS LOCATED FROM NEAR MINNEAPOLIS EXTENDING SSWWD
ACROSS THE DES MOINES AREA AND SWWD TO KANSAS CITY AND WICHITA.

FORECAST SOUNDINGS ACROSS THE SLIGHT RISK AREA LATE SUNDAY AFTERNOON
SHOW THE GREATEST DEEP LAYER SHEAR PROFILES IN THE UPPER MS VALLEY.
MODERATE TO STRONG DEEP LAYER SHEAR IS FORECAST FROM AROUND
MINNEAPOLIS NWD TO THE CANADIAN BORDER WHERE MLCAPE VALUES ARE
FORECAST IN THE 1500 TO 2000 J/KG RANGE. THIS SHOULD SUPPORT A
SUPERCELL THREAT WITH DISCRETE CELLS THAT INTENSIFY AHEAD OF THE
COLD FRONT. ALTHOUGH TEMPS ALOFT MAY BE ON THE WARM SIDE WITH 700 MB
TEMPS OF -9 C...THE ENVIRONMENT SHOULD STILL SUPPORT LARGE HAIL WITH
SUPERCELLS. A TORNADO THREAT MAY ALSO EXIST LATE SUNDAY AFTERNOON
INTO THE EVENING DUE TO THE STRONG LOW-LEVEL SHEAR ASSOCIATED WITH A
50 TO 60 KT LOW-LEVEL JET CENTERED OVER NE MN. A WIND DAMAGE THREAT
WILL ALSO LIKELY EXIST DUE TO 30 TO 40 KT OF FLOW JUST ABOVE THE SFC
AND STEEP LOW-LEVEL LAPSE RATES EVIDENT ON FORECAST SOUNDINGS. THE
WIND DAMAGE THREAT MAY BECOME ENHANCED DURING THE EARLY EVENING WHEN
A CONVECTIVE LINE IS FORECAST TO ORGANIZE ALONG THE FRONT.

FURTHER TO THE SOUTH ACROSS THE MID-MO VALLEY INTO THE CNTRL AND SRN
PLAINS...CONVECTION IS FORECAST TO INITIATE AHEAD OF THE FRONT AS A
CAPPING INVERSION WEAKENS IN THE LATE AFTERNOON. BY
00Z/MON...FORECAST SOUNDINGS FROM KANSAS CITY SWWD TO NEAR WICHITA
SHOW STRONG INSTABILITY WITH MLCAPE IN THE 3000 TO 4000 J/KG RANGE
BUT ONLY HAVE 0-6 KM SHEAR AROUND 20 KT. DUE TO THE
INSTABILITY...THIS ENVIRONMENT COULD STILL SUPPORT SUPERCELL
STRUCTURES WITH LARGE HAIL. HOWEVER...VERY STEEP LOW-LEVEL LAPSE
RATES AND THE WEAKER FLOW ALOFT MAY FAVOR OUTFLOW DOMINANT STORMS
WITH A THREAT FOR DAMAGING WIND GUSTS.

...CNTRL GULF COAST STATES...
AN UPPER-LEVEL TROUGH OVER THE CNTRL GULF COAST STATES IS FORECAST
TO MOVE VERY SLOWLY EWD ALONG THE COAST OF MS...AL AND THE FL
PANHANDLE. AS MODERATE DESTABILIZATION OCCURS ACROSS THE CNTRL GULF
COAST STATES SUNDAY...STRONG THUNDERSTORMS WILL BE POSSIBLE FROM
AROUND NEW ORLEANS EWD TO NEAR PENSACOLA. FORECAST SOUNDINGS ALONG
THIS CORRIDOR AT 21Z SHOW MLCAPE OF 1500 TO 2000 J/KG WITH 0-6 KM
SHEAR OF 25 KT. THIS ALONG WITH 30 KT OF FLOW AT 850 MB ANS STEEP
LOW-LEVEL LAPSE RATES SHOULD BE SUFFICIENT FOR A MARGINAL SEVERE
THREAT. HAIL AND STRONG GUSTY WINDS SHOULD BE THE PRIMARY THREATS
WITH THE MORE INTENSE MULTICELLS SUNDAY AFTERNOON.

..BROYLES.. 06/09/2012

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