I hate it when they say supercell

 ZCZC SPCPWOSPC ALL
   WOUS40 KWNS 101015
   ARZ000-KSZ000-MOZ000-OKZ000-101800-

   PUBLIC SEVERE WEATHER OUTLOOK
   NWS STORM PREDICTION CENTER NORMAN OK
   0515 AM CDT MON MAY 10 2010

   ...SEVERE THUNDERSTORMS EXPECTED OVER PARTS OF THE CENTRAL AND
   SOUTHERN PLAINS THIS AFTERNOON AND TONIGHT...

   THE NWS STORM PREDICTION CENTER IN NORMAN OK IS FORECASTING THE
   DEVELOPMENT OF A FEW STRONG...LONG-TRACK TORNADOES...LARGE HAIL AND
   DAMAGING WINDS OVER PARTS OF THE CENTRAL AND SOUTHERN PLAINS THIS
   AFTERNOON AND TONIGHT.

   THE AREAS MOST LIKELY TO EXPERIENCE THIS ACTIVITY INCLUDE

          EXTREME NORTHWEST ARKANSAS
          CENTRAL AND EASTERN KANSAS
          PARTS OF WESTERN MISSOURI
          CENTRAL AND EASTERN OKLAHOMA

   ELSEWHERE...SEVERE STORMS ARE ALSO POSSIBLE FROM SOUTHERN NEBRASKA
   TO THE MIDDLE MISSISSIPPI VALLEY AND SOUTHWARD TO PARTS OF TEXAS.

   A STRONG STORM SYSTEM TRACKING NORTHEASTWARD ACROSS KANSAS AND
   OKLAHOMA THIS AFTERNOON AND EVENING...REACHING THE MIDDLE
   MISSISSIPPI VALLEY LATER TONIGHT...WILL SUPPORT THE DEVELOPMENT OF
   SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT ACROSS PARTS OF
   CENTRAL KANSAS AND OKLAHOMA TO WESTERN MISSOURI AND NORTHWEST
   ARKANSAS.  STRONG SOUTHERLY LOW LEVEL WINDS WILL SUPPORT A CONTINUED
   NORTHWARD TRANSPORT OF MOISTURE THROUGH THE SOUTHERN AND CENTRAL
   PLAINS INTO THE OZARKS TO MIDDLE MISSISSIPPI VALLEY.  THIS MOISTURE
   COMBINED WITH SURFACE HEATING ACROSS WESTERN OKLAHOMA INTO SOUTHWEST
   KANSAS TODAY WILL CONTRIBUTE TO A VERY UNSTABLE AIR MASS BY LATE
   AFTERNOON.  THE ARRIVAL OF STRONG SOUTHWESTERLY MIDDLE LEVEL WINDS
   ATOP THE SOUTHERLY WINDS NEAR THE SURFACE WILL RESULT IN FAVORABLE
   CONDITIONS FOR FAST MOVING SEVERE STORMS PRODUCING A FEW STRONG...
   LONG-TRACK TORNADOES...LARGE HAIL AND DAMAGING WINDS BEGINNING
   ACROSS CENTRAL PARTS OF KANSAS AND OKLAHOMA IN THE LATE AFTERNOON.
   ATMOSPHERIC CONDITIONS WILL REMAIN FAVORABLE FOR THESE STRONG TO
   SEVERE STORMS TO SPREAD NEWD INTO PARTS OF MISSOURI AND NORTHWEST
   ARKANSAS TONIGHT.

   STATE AND LOCAL EMERGENCY MANAGERS ARE MONITORING THIS POTENTIALLY
   VERY DANGEROUS SITUATION. THOSE IN THE THREATENED AREA ARE URGED TO
   REVIEW SEVERE WEATHER SAFETY RULES AND TO LISTEN TO
   RADIO...TELEVISION...AND NOAA WEATHER RADIO FOR POSSIBLE
   WATCHES...WARNINGS...AND STATEMENTS LATER TODAY.

   ..PETERS.. 05/10/2010

SPC AC 101233

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0733 AM CDT MON MAY 10 2010

VALID 101300Z – 111200Z

…THERE IS A HIGH RISK OF SVR TSTMS LATE THIS AFTERNOON/EVENING FOR
CENTRAL/NE OK AND SE KS…

…THERE IS A MDT RISK OF SVR TSTMS SURROUNDING THE HIGH RISK IN
KS…OK…SW MO…AND NW AR…

…THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL/NW TX TO THE
CENTRAL PLAINS AND MID MS VALLEY THROUGH TONIGHT…

…A FEW STRONG/LONG-TRACK TORNADOES…ALONG WITH VERY LARGE HAIL
AND DAMAGING WINDS…WILL BE POSSIBLE THIS AFTERNOON/EVENING ACROSS
CENTRAL/NE OK AND EXTREME S CENTRAL/SE KS…

…SRN/CENTRAL PLAINS THIS AFTERNOON TO MO OVERNIGHT…
RAPID CHANGES ARE EXPECTED TODAY ACROSS THE SRN/CENTRAL PLAINS AS A
PRONOUNCED SHORTWAVE TROUGH NEAR THE FOUR CORNERS MOVES QUICKLY EWD
TO CENTRAL KS/NRN OK BY THIS EVENING…AND CONTINUES ENEWD TO THE
MID MS VALLEY OVERNIGHT. A SURFACE WARM FRONT AND ASSOCIATED MOIST
AIR MASS /BOUNDARY LAYER DEWPOINTS OF 65-70 F/ WILL SURGE NWD FROM
NW/N CENTRAL TX TO CENTRAL AND NRN OK BY MID-LATE AFTERNOON. THIS
MOISTENING WILL OCCUR BENEATH A PLUME OF STEEP MIDLEVEL LAPSE RATES
AND IN RESPONSE TO EWD DEVELOPMENT OF THE SURFACE CYCLONE ACROSS
SW/S CENTRAL KS. THE MOST FAVORABLE PHASING OF THE UNSTABLE WARM
SECTOR AND STRONG VERTICAL SHEAR ENVIRONMENT WILL OCCUR LATE THIS
AFTERNOON/EVENING ACROSS CENTRAL/N CENTRAL/NE OK…AND THE ADJACENT
BORDER COUNTIES IN KS. OVERNIGHT…THE BELT OF STRONGER FORCING FOR
ASCENT WILL ACCELERATE ENEWD OVER MO AT A FASTER RATE THAN THE LOW
LEVELS WILL BE ABLE TO MOISTEN/DESTABILIZE…RESULTING IN A DECREASE
IN THE SEVERE STORM/TORNADO RISK LATER TONIGHT.

DISCRETE THUNDERSTORM INITIATION IS EXPECTED BY 18-20Z IN SW KS NEAR
THE SURFACE LOW AND LEFT EXIT REGION OF THE MID-UPPER JET.
ADDITIONAL DEVELOPMENT WILL OCCUR FARTHER SE ALONG THE SRN KS/NRN OK
DRYLINE AROUND 21-22Z…WITH ISOLATED STORMS POSSIBLE SWD INTO
CENTRAL OK AND NW TX CLOSER TO 22-00Z. THE STRONG DEEP-LAYER SHEAR
ENVIRONMENT NEAR THE MID-UPPER JET CORE SUGGESTS THAT STORMS MAY
TAKE UP TO AN HOUR OR SO TO MATURE. HOWEVER…EFFECTIVE SRH OF
400-600 M2/S2…BOUNDARY LAYER DEWPOINTS OF 65-70 F AND MLCAPE OF
2000-3500 J/KG ALL FAVOR THE POTENTIAL FOR STRONG/LONG-TRACK
TORNADOES IN THE MDT-HIGH RISK AREAS. THE TORNADO AND LARGE HAIL
THREAT SHOULD MAXIMIZE FROM ABOUT 22-02Z IN OK/SE KS…WITH A
GRADUAL EVOLUTION TO A MORE LINEAR CONVECTIVE MODE WITH DAMAGING
WINDS/LARGE HAIL OVERNIGHT ACROSS MO.

POTENTIAL CONCERNS WILL BE THE LATE ARRIVAL AND NARROW WIDTH OF THE
WARM SECTOR COMPARED TO THE STRONG VERTICAL SHEAR PROFILES AND FAST
STORM MOTIONS. A COMPARISON OF EXPECTED 45-50 KT STORM MOTIONS WITH
WARM SECTOR WIDTH/PROGRESSION SUGGESTS A 2-3 HOUR WINDOW FOR
SUPERCELLS TO MATURE AND REMAIN WITHIN THE CORRIDOR OF STRONGER
INSTABILITY ACROSS EXTREME SRN/SERN KS AND NRN/NERN OK THIS EVENING.
STILL…IT APPEARS THIS WINDOW OF OPPORTUNITY WILL BE SUFFICIENTLY
LONG TO SUPPORT A SIGNIFICANT SUPERCELL/TORNADO RISK FOR A FEW HOURS
LATE THIS AFTERNOON/EVENING…INCLUDING THE WICHITA…TULSA…AND
OKLAHOMA CITY METROPOLITAN AREAS.

..THOMPSON/HURLBUT.. 05/10/2010