National Weather Service Raw Text Product

134 
ACUS01 KWNS 111625
SWODY1
SPC AC 111623

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1023 AM CST WED NOV 11 2015

VALID 111630Z - 121200Z

...THERE IS AN ENH RISK OF SVR TSTMS THIS AFTERNOON/EVENING FOR SRN
IA...NRN MO...AND W CENTRAL IL...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE ENH RISK
AREA...FROM EXTREME NE KS AND SW IA EWD ACROSS MUCH OF CENTRAL AND
NRN IL...

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON/EVENING INVOF
THE ARKLATEX...

...THERE IS A MRGL RISK OF SVR TSTMS FROM SE TX TO PARTS OF THE MID
MS/LOWER OH VALLEYS AND SRN LAKE MI...

...SUMMARY...
STRONG TO SEVERE THUNDERSTORMS ARE EXPECTED TO DEVELOP DURING THE
AFTERNOON ACROSS PARTS OF THE MISSOURI VALLEY SOUTH-SOUTHWESTWARD
INTO EASTERN TEXAS. THE GREATEST CONCENTRATION OF POTENTIALLY SEVERE
STORMS THIS AFTERNOON AND EVENING SHOULD EXIST ACROSS PARTS OF IOWA
AND NORTHERN MISSOURI INTO NORTHERN AND CENTRAL ILLINOIS.

...SYNOPSIS...
A STRONG MIDLEVEL SHORTWAVE TROUGH WILL PROGRESS ENEWD FROM THE
CENTRAL PLAINS TO THE MID MS VALLEY BY THIS EVENING...AND CONTINUE
TO THE GREAT LAKES/OH VALLEY OVERNIGHT.  AN ASSOCIATED SURFACE
CYCLONE IN N CENTRAL KS AS OF LATE MORNING WILL DEVELOP NEWD TO
CENTRAL IA THIS EVENING AND WI OVERNIGHT...AS A REMNANT LEE
TROUGH/DRYLINE MOVES EWD FROM KS/OK TO MO/WRN AR...BEFORE BEING
OVERTAKEN BY THE SURFACE COLD FRONT THIS EVENING.  LOW-LEVEL
MOISTURE IS SPREADING NWD/NEWD FROM E TX IN THE WARM SECTOR...THOUGH
THE RICHER MOISTURE WILL LIKELY REMAIN SOMEWHAT DISPLACED FROM THE
STEEPER LAPSE RATES CLOSER TO THE SURFACE LOW AND MIDLEVEL TROUGH. 
THUS...THE SEVERE STORM RISK SHOULD BE RELATIVELY GREATER CLOSER TO
THE SURFACE CYCLONE...AND FARTHER S WHERE LOW-LEVEL
MOISTURE/BUOYANCY WILL BE LARGEST ACROSS NE TX.

...IA/NRN MO/WRN IL THROUGH THIS EVENING...
THE SURFACE CYCLONE IN N CENTRAL KS WILL DEVELOP NEWD ALONG A
STALLED FRONT TOWARD CENTRAL IA THIS EVENING.  12Z SOUNDINGS SHOWED
THE STEEPEST MIDLEVEL LAPSE RATES ALONG AND JUST N OF THE MIDLEVEL
JET CORE...AND THIS AREA WILL COINCIDE WITH THE N EDGE OF THE
RETURNING LOW-LEVEL MOISTURE /BOUNDARY LAYER DEWPOINTS 55-60 F/. 
FOCUSED FORCING FOR ASCENT WILL SPREAD NEWD IN CONJUNCTION WITH THE
SURFACE LOW/MIDLEVEL TROUGH...REACHING EXTREME NE KS/SE NEB/SW IA/NW
MO BY AROUND 18Z.  SURFACE-BASED CONVECTIVE INITIATION IS EXPECTED
IN THE 18-20Z TIME FRAME IN A NW-SE ARC CLOSE TO THE MO RIVER FROM
KANSAS CITY TO OMAHA...WITH STORMS EXPECTED TO SPREAD QUICKLY EWD
THROUGH THE AFTERNOON/EVENING ACROSS NRN MO/SRN IA.  THOUGH MOISTURE
AND BUOYANCY WILL NOT BE PARTICULARLY LARGE...VERTICAL SHEAR WILL
FAVOR A BROKEN BAND OF LOW-TOPPED SUPERCELLS CAPABLE OF PRODUCING A
FEW TORNADOES...DAMAGING GUSTS...AND ISOLATED LARGE HAIL.  THERE
WILL BE SOME POTENTIAL FOR STORMS TO CONGEAL INTO A MORE SOLID LINE
LATER THIS AFTERNOON/EVENING...WITH A CONTINUED DAMAGING WIND RISK
INTO WRN IL.  INTO THE OVERNIGHT HOURS...CONVECTION WILL WEAKEN AS
ALREADY MARGINAL BUOYANCY FURTHER DIMINISHES WITH EWD EXTENT.

...ARKLATEX THIS AFTERNOON/EVENING...
LOW-MID 70S BOUNDARY LAYER DEWPOINTS ARE SPREADING NWD/NEWD TOWARD
THE ARKLATEX AS OF MID MORNING.  LAPSE RATES ALOFT ARE NOT
PARTICULARLY STEEP AND LOW-LEVEL SHEAR WILL BE WEAKER COMPARED TO
AREAS FARTHER NE IN CLOSER PROXIMITY TO THE SURFACE LOW.  STILL...A
FEW CLOUD BREAKS AND THE RICH MOISTURE COULD BOOST MLCAPE TO
1000-1500 J/KG BY MID-LATE AFTERNOON ACROSS E/NE TX...WITH SOMEWHAT
WEAKER BUOYANCY EXPECTED FARTHER TO THE NE INTO SRN AR.  A FEW
STORMS SHOULD FORM THIS AFTERNOON ALONG THE REMNANT
DRYLINE/CONFLUENCE BAND WHICH WILL APPROACH THE ARKLATEX FROM THE
W...AND CONVECTION WILL SUBSEQUENTLY MOVE NEWD INTO THIS EVENING. 
DEEP-LAYER SHEAR AND BUOYANCY WILL BE SUFFICIENT FOR
SUPERCELLS...WITH AT LEAST SOME RISK FOR A TORNADO OR TWO...IN
ADDITION TO A FEW DAMAGING GUSTS.

...SRN MO/NRN AR THIS AFTERNOON/EVENING...
VERTICAL SHEAR PROFILES WILL BE FAVORABLE FOR SEMI-DISCRETE
SUPERCELLS ALONG THE REMNANT DRYLINE FROM NW AR INTO SW MO THIS
AFTERNOON.  HOWEVER...BUOYANCY IS EXPECTED TO REMAIN QUITE MARGINAL
AS A RESULT OF THE STEEPER LAPSE RATES REMAINING FARTHER N...THE
RICHER MOISTURE REMAINING FARTHER S...AND CLOUDS LIMITING SURFACE
HEATING.  THUS...ATTEMPTS AT SURFACE-BASED CONVECTION MAY END UP
BEING OVERWHELMED BY THE VERY STRONG VERTICAL SHEAR ACROSS THIS
AREA.  WILL MAINTAIN LOW WIND/TORNADO PROBABILITIES TO REFLECT THE
CONDITIONAL SEVERE RISK...BUT THE OVERALL SEVERE/SUPERCELL RISK
SHOULD REMAIN MARGINAL.

..THOMPSON/PICCA.. 11/11/2015

$$