May 9, 2015 0600 UTC Day 1 Convective Outlook

 DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1259 AM CDT SAT MAY 09 2015

   VALID 091200Z - 101200Z

   ...THERE IS A MDT RISK OF SVR TSTMS OVER SE CO...SW KS AND A SMALL
   PART OF NW OK...

   ...THERE IS AN ENH RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL HIGH
   PLAINS TO WRN OK AND THE ERN TX PANHANDLE...

   ...THERE IS AN ENH RISK OF SVR TSTMS FROM THE EDWARDS PLATEAU TO
   N-CNTRL TX...

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL/SRN
   GREAT PLAINS...

   ...THERE IS A MRGL RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL
   STATES...

   ...SUMMARY...
   SCATTERED SEVERE STORMS ARE EXPECTED ACROSS PARTS OF THE CENTRAL AND
   SOUTHERN GREAT PLAINS. THE MOST PROBABLE CORRIDOR FOR TORNADOES AND
   VERY LARGE HAIL IS FROM EAST-CENTRAL COLORADO TO THE EASTERN TEXAS
   PANHANDLE AND NORTHWEST OKLAHOMA FROM MID-AFTERNOON TO EARLY
   EVENING.

   ...SYNOPSIS...
   SHORTWAVE TROUGH OVER THE LOWER CO RIVER VALLEY SHOULD TRACK E TO
   THE SRN ROCKIES BY 10/00Z...BEFORE ADVANCING MORE SLOWLY NE OVER THE
   CNTRL HIGH PLAINS TONIGHT. LEE CYCLOGENESIS WILL OCCUR TODAY OVER
   SE/E-CNTRL CO. A WARM FRONT SHOULD DEVELOP E OVER KS TODAY AND
   EVENTUALLY NE TOWARDS THE MID-MO VALLEY TONIGHT. DRYLINE WILL MIX E
   OVER THE SRN HIGH PLAINS BUT ITS ADVANCEMENT SHOULD BE SLOWED BY
   MORNING CONVECTION. CONVECTIVE OUTFLOW/CURRENT EFFECTIVE FRONTAL
   BOUNDARY FROM N-CNTRL TX TO THE PERMIAN BASIN WILL ATTEMPT TO
   ADVANCE N BUT MAY BE STUNTED BY MORNING CONVECTION OVER THE SRN HIGH
   PLAINS. A PACIFIC COLD FRONT SHOULD OVERTAKE THE DRYLINE TONIGHT.

   ...CNTRL/SRN GREAT PLAINS...
   ANOTHER MESSY/COMPLEX FORECAST AS EXTENSIVE CONVECTIVE OVERTURNING
   OCCURRED ON FRI AND MORNING CONVECTION IS EXPECTED TO BE ONGOING.
   CONVECTIVELY PARAMETRIZED GUIDANCE APPEARS LIKELY TO BE TOO UNSTABLE
   IN THE PORTION OF THE WARM SECTOR N OF THE LARGE-SCALE CONVECTIVE
   OUTFLOW BOUNDARY CURRENTLY FROM N-CNTRL TX TO THE PERMIAN BASIN.
   WHILE A HIGHER-END SCENARIO IS CERTAINLY POSSIBLE TODAY...BUST
   POTENTIAL IS ALSO APPARENT. FOR THIS OUTLOOK...WILL FOCUS ON TWO
   CORRIDORS OF MORE CONCENTRATED SEVERE POTENTIAL WITHIN A BROADER
   ORGANIZED SEVERE RISK.

   TSTMS SHOULD DEVELOP THIS MORNING IN BETWEEN ONGOING ACTIVITY OVER
   ERN CO AND THE PERMIAN BASIN. LARGE-SCALE ASCENT WILL BECOME
   PRONOUNCED AS MID-LEVEL HEIGHT FALLS/DCVA INCREASE AND ROBUST
   LOW-LEVEL WAA OCCURS ATOP THE CONVECTIVE OUTFLOW IN W TX. ISOLATED
   LARGE HAIL SHOULD BE THE PRIMARY HAZARD WITH THESE EARLY-DAY STORMS.
   SOME OF THIS ACTIVITY MAY INTENSIFY IN CONCERT WITH THE DIURNAL
   HEATING CYCLE...PARTICULARLY ALONG THE CURRENT OUTFLOW BOUNDARY AS
   IT ATTEMPTS TO ADVANCE N OVER N TX AND OK. DEEP-LAYER SHEAR PROFILES
   WOULD FAVOR ALL SEVERE HAZARDS...BUT LIKELY MESSY CONVECTIVE MODE
   AND LACK OF STRONG DIABATIC HEATING SUGGESTS THE OVERALL RISK MAY BE
   LIMITED.

   STEEPEST TROPOSPHERIC LAPSE RATES SHOULD LIE THIS AFTERNOON FROM
   E-CNTRL CO TO THE TX/OK PANHANDLES. BENEATH AND N OF AN INTENSE
   MID-LEVEL JET /AROUND 75 KT AT 500 MB/ CURLING FROM THE SRN HIGH
   PLAINS TO WRN KS...WIND PROFILES WOULD SEEMINGLY BE FAVORABLE FOR
   SEVERAL DISCRETE SUPERCELLS AND A RISK FOR SIGNIFICANT-SIZED LARGE
   HAIL AND TORNADOES. BUT VEER-BACK SIGNATURES ARE EVIDENT IN FORECAST
   SOUNDINGS GIVEN THE RELATIVELY MERIDIONAL WIND PROFILE. ALONG WITH
   CONCERNS OVER THE DEGREE OF BOUNDARY-LAYER MOISTURE AND DIABATIC
   HEATING...WILL REFRAIN FROM MODERATE-RISK TYPE TORNADO PROBABILITIES
   THIS OUTLOOK. SOME CONSOLIDATION OF LATE DAY CONVECTION INTO AN MCS
   ACROSS PARTS OF CNTRL KS APPEARS PLAUSIBLE. THE RISK FOR SEVERE
   WINDS MAY INCREASE...BUT CONFIDENCE IS TOO LOW TO WARRANT ENHANCED
   PROBABILITIES GIVEN CONCERNS OVER THE DEGREE OF INSTABILITY WITH ERN
   EXTENT THIS EVENING.

   FARTHER S FROM THE EDWARDS PLATEAU TO N-CNTRL TX...AN EXPANDING
   CLUSTER OF STORMS SHOULD DEVELOP TONIGHT AS THE PACIFIC COLD FRONT
   IMPINGES ON THE WRN PERIPHERY OF THE PERSISTENT MARITIME TROPICAL
   AIR. CONVECTION SHOULD PRIMARILY REMAIN ANAFRONTAL GIVEN THE
   ORIENTATION OF DEEP SHEAR/ASCENT RELATIVE TO THE FRONT. LARGE
   BUOYANCY AND STRONG EFFECTIVE SHEAR SHOULD FOSTER ELEVATED SUPERCELL
   STRUCTURES WITH A RISK FOR LARGE HAIL. WITH MULTIPLE EPISODES OF
   SEVERE STORMS POSSIBLE DURING THE DAY AND TONIGHT...HAVE
   MAINTAINED/INCREASED AREAL EXTENT OF THE ENHANCED RISK.