May 27, 2013 1300 UTC Day 1 Convective Outlook
Updated: Mon May 27 12:50:37 UTC 2013
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20130527 1300 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20130527 1300 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Probabilistic Damaging Wind Graphic
20130527 1300 UTC Day 1 Damaging Wind Probabilities Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Probabilistic Large Hail Graphic
20130527 1300 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MODERATE 23,640 423,925 Salina, KS...Beatrice, NE...Smith Center, KS...Byron, NE...
SLIGHT 301,403 9,862,901 Kansas City, MO...Omaha, NE...Wichita, KS...Lincoln, NE...Des Moines, IA...
   SPC AC 271247

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0747 AM CDT MON MAY 27 2013

   VALID 271300Z - 281200Z

   ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF KS AND NEB...

   ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK
   AREA...FROM THE NRN HIGH PLNS THROUGH THE CNTRL PLNS TO THE MID MS
   VLY AND PARTS OF THE SRN PLNS...

   ...SYNOPSIS...
   SLOWLY PROGRESSIVE...DIFFLUENT...LARGE-SCALE TROUGH WILL PREVAIL
   OVER THE WEST THIS PERIOD...WHILE A SERIES OF LESSER...FASTER-MOVING
   DISTURBANCES FLATTEN RIDGE OVER ERN PORTIONS OF THE PLNS AND THE MS
   VLY. ONE SUCH IMPULSE NOW OVER ID WILL CONTINUE NE INTO SE MT THIS
   EVE...AND INTO ND EARLY TUE. IN A BRANCH OF SOMEWHAT ENHANCED SWLY
   FLOW FARTHER S...SEVERAL WEAK IMPULSES NOW OVER THE FOUR CORNERS
   REGION AND CO ARE POISED TO TRACK NE INTO THE CNTRL PLNS.

   AT THE SFC...LOW NOW OVER WRN KS WILL REMAIN NEARLY STNRY WHILE
   ELONGATING NEWD IN RESPONSE TO PASSING SRN STREAM DISTURBANCES.
   BROAD CURRENT OF MOIST SSWLY LOW-LVL FLOW E OF THE LOW WILL ONCE
   AGAIN SERVE TO SUPPORT SEVERAL ROUNDS OF DIURNALLY-ENHANCED TSTM
   DEVELOPMENT. THE MOST CONCENTRATED ACTIVITY IS EXPECTED NEAR
   WARM/STNRY FRONT EXTENDING FROM SRN NEB ESE INTO THE MID MS
   VLY...AND ALONG OUTFLOW BOUNDARIES LEFT BY OVERNIGHT STORMS IN THE
   SAME GENERAL REGION. 

   ...CNTRL PLNS/LWR MO VLY ESE TO MID MS VLY TODAY/TNGT...
   WNW-ESE ORIENTED FRONT...ENHANCED BY CONVECTIVE OUTFLOW FROM
   OVERNIGHT MCS NOW IN NE KS/NW MO...LIKELY WILL BE THE MAIN FOCUS FOR
   STRONG TO SVR STORMS THIS PERIOD. ELEVATED STORMS ATOP THE MCS COLD
   POOL IN ERN NEB...AND LEADING-LINE CONVECTION IN KS-MO...MAY POSE AN
   ISOLD SVR HAIL/WIND THREAT THROUGH MID MORNING. BUT A MORE
   APPRECIABLE SVR THREAT MAY EVOLVE THIS AFTN AND EVE AS SFC HEATING
   AND APPROACH OF SRN STREAM DISTURBANCES FURTHER DESTABILIZE REGION.

   ATTM IT APPEARS THAT THE MOST LIKELY AREA FOR AFTN/EVE SVR STORM 
   DEVELOPMENT WILL BE NEAR INTERSECTION OF OUTFLOW BOUNDARY/FRONT WITH
   ELONGATING KS SFC LOW. WIND PROFILES IN THIS REGION SHOULD BE
   FAVORABLE FOR SUPERCELLS...WITH 30-40 SSWLY 850 MB WINDS VEERING TO
   40 KT WSWLY FLOW AT 500 MB. COUPLED WITH MODEST BUT MOIST/BACKED
   NEAR-SFC WINDS INVOF FRONT/OUTFLOW BOUNDARY...SETUP COULD YIELD A
   CLUSTER OF SUPERCELLS WITH A SIZABLE RISK FOR TORNADOES /ONE OR TWO
   POSSIBLY STRONG/ IN N CNTRL KS AND PERHAPS ADJACENT SRN NEB...IN
   ADDITION TO LARGE HAIL/DMGG WIND. A FEW SVR STORMS ALSO COULD FORM
   FARTHER WNW OVER THE NEB PANHANDLE...NE CO...AND NW KS...WHERE MOIST
   ELY FLOW ON N SIDE OF KS LOW IMPINGES ON INVERTED SFC TROUGH.  

   CONTINUED NE MOTION OF SRN STREAM UPR DISTURBANCES...AND DIURNAL
   INFLUENCES...SHOULD FURTHER STRENGTHEN 850 MB SSW FLOW ACROSS THE
   ERN HALF OF KS AND MUCH OF MO TNGT. IN ADDITION TO POSSIBLY
   MAINTAINING A RISK FOR TORNADOES INTO MID-EVE...EXPECT THAT
   STRENGTHENED LOW-LVL FLOW ALSO WILL PROMOTE FAIRLY WIDESPREAD MCS
   DEVELOPMENT FROM PARTS OF NEB/SRN SD ESE INTO IA AND NRN MO. THESE
   SYSTEMS MAY BECOME FAIRLY WELL-ORGANIZED...WITH ASSOCIATED BOWING
   SEGMENTS POSING A RISK FOR HIGH WIND...HAIL...AND HEAVY RAIN THROUGH
   EARLY TUE.  

   ...NRN HIGH PLNS THIS AFTN/EVE...
   SFC HEATING...WEAK UPSLOPE FLOW...AND ASCENT AHEAD OF ID UPR IMPULSE
   SHOULD PROMOTE ANOTHER ROUND OF STRONG TO SVR TSTMS ALONG AN ARC
   FROM ERN MT SSE INTO NE WY AND THE WRN DAKOTAS LATER TODAY INTO
   TNGT. WHILE THE WIND/THERMODYNAMIC ENVIRONMENT DOES NOT APPEAR IDEAL
   FOR A STRONGLY-ORGANIZED SVR WEATHER EVENT...SUFFICIENT SHEAR AND
   BUOYANCY WILL EXIST FOR A FEW SUSTAINED STORMS AND SUPERCELLS
   CAPABLE OF HAIL AND HIGH WIND. THIS ACTIVITY SHOULD FOCUS ALONG
   INVERTED TROUGH EXTENDING NNW FROM KS SFC LOW...AND COULD EVOLVE
   INTO A BAND OR CLUSTER POSING A SOMEWHAT GREATER DMGG WIND THREAT BY
   EARLY EVE.

   ...SRN HIGH PLNS THIS AFTN/EVE...
   ISOLD TO WDLY SCTD TSTMS SHOULD FORM ALONG SRN PLNS DRY LINE LATE
   THIS AFTN AND EVE...WHERE UPR DIFFLUENCE AND WNWLY DEEP SHEAR WILL
   BE SOMEWHAT ENHANCED /30-35 KTS/ ALONG AND JUST S OF SRN BRANCH JET.
   COMBINATION OF FAIRLY RICH MOISTURE /PW AOA 1.25 INCHES WITH SFC DEW
   POINTS IN THE MID 60S F/...CONTINUING PRESENCE OF AN EML...AND
   STRONG SFC HEATING SHOULD YIELD MODERATE TO STRONG
   INSTABILITY...WITH SBCAPE AOA 2000 J/KG. THIS SETUP MAY YIELD
   SUPERCELLS CAPABLE OF LARGE HAIL/LOCALLY DMGG WIND AND POSSIBLY A
   TORNADO OR TWO....ESPECIALLY IN THE ERN TX PANHANDLE...NW TX...AND
   WRN OK.

   ..CORFIDI/BOTHWELL.. 05/27/2013

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