June 19- Day 2 Update (12:57 pm CDT)

...THERE IS A MDT RISK OF SVR TSTMS OVER ERN NEB...SERN SD...SRN
   MN...AND MUCH OF IA...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE CENTRAL AND SRN PLAINS
   ACROSS THE MIDDLE MS AND OH VALLEYS INTO THE SRN APPALACHIANS AND
   CAROLINAS...
   
   ...ACTIVE SEVERE WEATHER DAY EXPECTED MONDAY ESPECIALLY OVER THE MID
   MO RIVER VALLEY...
   
   ...SYNOPSIS...
   SATELLITE IMAGERY SHOWS A STRONG DEVELOPING LOW/UPPER VORTICITY MAX
   DIGGING SEWD ACROSS THE GREAT BASIN.  THIS IS AMPLIFYING THE WRN US
   LONG WAVE TROUGH AS AN UPPER LOW SLOWLY RETROGRADES FROM SASK INTO
   ERN ALTA.  MODELS ARE IN EXCELLENT AGREEMENT INDICATING THE GREAT
   BASIN LOW WILL MOVE EWD ACROSS THE CENTRAL/SRN ROCKIES TONIGHT
   BEFORE LIFTING NEWD ACROSS THE CENTRAL PLAINS ON MONDAY.  AT THE
   SURFACE...A LOW INITIALLY OVER WRN KS AT 20/12Z IS FORECAST TO MOVE
   NEWD ACROSS ERN NEB...WHILE A COLD FRONT TRAILING SWWD FROM THE LOW
   SURGES EWD ACROSS THE CENTRAL PLAINS AND OVERTAKES A LEADING DRY
   LINE OVER PARTS OF KS AND OK.  STEEP LAPSE RATES ABOVE A CAPPING
   INVERSION ASSOCIATED WITH A STRONG EML IS EXPECTED TO INHIBIT
   CONVECTIVE DEVELOPMENT IN THE MOIST AND VERY UNSTABLE PLAINS WARM
   SECTOR UNTIL LATER IN THE AFTERNOON AND EVENING...WHILE ELEVATED
   STORMS ARE LIKELY TO OCCUR TO THE NORTH OF THE SURFACE LOW AND WARM
   FRONT MOVING NWD OVER THE LOWER MO VALLEY.
   
   ...ERN NEB...SERN SD...SRN MN...AND MUCH OF IA...
   STRONG DYNAMIC FORCING FOR LARGE-SCALE ASCENT WILL OVERSPREAD THIS
   REGION DURING THE DAY WITHIN THE LEFT EXIT REGION OF THE MID/UPPER
   LEVEL JET STREAK TRANSLATING THROUGH THE SRN/ERN QUADS OF THE PLAINS
   UPPER LOW.  ELEVATED STORMS ARE EXPECTED TO BE ONGOING NORTH OF THE
   LOW AND WARM FRONT DURING THE MORNING WITH POTENTIAL FOR HAIL WITH
   STRONGER CELLS.  CONVECTION IS EXPECTED TO INTENSIFY BY MID
   AFTERNOON FROM PARTS OF CENTRAL/NERN NEB INTO SERN SD...SRN MN AND
   NRN IA WHERE BACKED LOW LEVEL WINDS ENHANCE VERTICAL SHEAR AS THE
   UPPER JET STREAK APPROACHES FROM THE SOUTHWEST. BY LATE
   AFTERNOON/EARLY EVENING...CONTINUED DIABATIC HEATING COUPLED WITH
   LOW LEVEL CONVERGENCE NEAR THE LOW AND COLD FRONT SHOULD WEAKEN THE
   CAP SUFFICIENTLY FOR ADDITIONAL STORMS TO FORM ALONG/AHEAD OF THE
   COLD FRONT OVER ERN NEB.  THESE STORMS WILL MOVE INTO PARTS OF IA
   DURING THE EVENING. THE FAVORABLE SHEAR PROFILES WILL SUPPORT
   SUPERCELL DEVELOPMENT...ESPECIALLY NEAR THE WARM FRONT AND WITH
   INITIAL STORMS NEAR THE COLD FRONT...WITH A THREAT FOR SEVERAL
   STRONG TORNADOES...VERY LARGE HAIL AND DAMAGING WIND GUSTS. 
   ACTIVITY IS EXPECTED TO PERSIST INTO THE OVERNIGHT HOURS AS THE LOW
   LEVEL JET STRENGTHENS AFTER DARK WITH CONTINUING THREAT OF SEVERE
   STORMS CAPABLE OF MAINLY DAMAGING WINDS AND LARGE HAIL.
   
   ...CENTRAL/ERN KS SWD INTO OK AND NRN TX...
   STORM ARE EXPECTED TO DEVELOP SWD ALONG THE COLD FRONT OVER ERN KS
   BY LATE AFTERNOON AS DYNAMIC FORCING FOR ASCENT COUPLED WITH FRONTAL
   CONVERGENCE WEAKENS THE CAP.  MODELS SUGGEST A RELATIVELY NARROW
   AXIS OF STRONG DEEP LAYER SHEAR WILL ACCOMPANY THE COLD FRONT AS IT
   MOVES INTO THE VERY UNSTABLE AIR MASS.  SEVERE STORMS ARE LIKELY TO
   OCCUR WITH POTENTIAL FOR VERY LARGE HAIL...DAMAGING WIND GUSTS...AND
   A FEW TORNADOES.  THE ACTIVITY IS EXPECTED TO DEVELOP INTO A LINE
   WITHIN THE FIRST FEW HOURS AFTER CONVECTIVE INITIATION GIVEN THE
   PARALLEL ORIENTATION OF THE LOW-MID LEVEL SHEAR VECTORS AND THE COLD
   FRONT...WITH THE SEVERE THREAT TRANSITIONING TO PRIMARILY DAMAGING
   WIND GUSTS AND LARGE HAIL AFTER SUNSET.
   
   FARTHER SOUTH...SEVERE STORM POTENTIAL WILL BECOME GRADUALLY MORE
   CONDITIONAL WITH SWD EXTENT ACROSS OK INTO NRN TX AS DYNAMIC FORCING
   ASSOCIATED WITH THE UPPER LOW LIFTS NEWD AWAY FROM THE AREA. 
   HOWEVER...THREAT FOR SEVERE STORMS INCLUDING INITIAL DISCRETE
   SUPERCELLS WILL EXIST FROM THE LATE AFTERNOON THROUGH THE EVENING
   HOURS.  VERY LARGE HAIL WILL BE MOST LIKELY WITH SUPERCELLS IN
   OK...WITH DAMAGING WIND GUSTS ALSO POSSIBLE WITH ANY STRONG STORMS
   THAT DO DEVELOP GIVEN THE STEEP LAPSE RATES.
   
   ...MID MS VALLEY INTO UPPER OH VALLEY AND THE SRN APPALACHIANS AND
   CAROLINAS...
   ONE OR TWO FORWARD PROPAGATING MCS/S ARE EXPECTED TO MOVE EWD/ESEWD
   THROUGH THE OH VALLEY REGION IN ASSOCIATION WITH MODERATELY STRONG
   UNIDIRECTIONAL FLOW ACROSS THE AREA.  THESE STORMS ARE EXPECTED TO
   MOVE SEWD WITH TIME AND REACH THE APPALACHIANS DURING THE MORE
   FAVORABLE DIURNAL PERIOD FOR SEVERE SYSTEMS TO CROSS THE MOUNTAINS. 
   THIS IS SUPPORTED BY THE HIGH RES WINDOW WRF MODEL RUNS SHOWING
   BOWING CONVECTIVE SYSTEMS MOVING INTO THE CAROLINAS AROUND 21/00Z. 
   DAMAGING WIND GUSTS AND OCCASIONAL HAIL WILL BE POSSIBLE ACROSS
   THESE REGIONS.