SPC 1200Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1240 AM CDT SUN JUN 10 2012 VALID 101200Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MS VALLEY TO NCNTRL OK... ...MID-UPPER MS VALLEY TO NCNTRL OK... STRONG HEIGHT FALLS WILL SPREAD ACROSS THE NRN PLAINS INTO THE UPPER MS VALLEY SUNDAY IN RESPONSE TO EWD MOVING SHORT-WAVE TROUGH. AT THE SFC...COLD FRONT IS EXPECTED TO SURGE INTO THE UPPER MS VALLEY EARLY IN THE PERIOD WITH A MID AFTERNOON POSITION LOCATED FROM NCNTRL MN...SSWWD INTO SERN NEB AND CNTRL KS. IN ALL LIKELIHOOD THE WARM SECTOR WILL REMAIN CAPPED THROUGH MUCH OF THE AFTERNOON ALONG CNTRL/SRN PORTIONS OF THE BOUNDARY AS VERY WARM EML HAS OVERSPREAD MUCH OF THE PLAINS WITH 700 MB TEMPERATURES IN EXCESS OF 14C AS FAR NORTH AS SERN SD. EARLY IN THE PERIOD IT APPEARS POST FRONTAL ELEVATED CONVECTION WILL BE ONGOING ACROSS THE ERN DAKOTAS...AIDED IN PART BY AFOREMENTIONED SHORT-WAVE TROUGH. THIS ACTIVITY SHOULD SPREAD EAST INTO THE UPPER MS VALLEY BY MID DAY WITH FRONTAL CONVECTION POSSIBLY DEVELOPING BY 18-21Z ACROSS NRN MN AS LARGE SCALE FORCING AND MID LEVEL COOLING REMOVE THE CAP. LATEST NAM GUIDANCE EXHIBITS A STRONGLY SHEARED AND UNCAPPED PROFILE BY 18Z AT BJI WITH ROUGHLY 2500 J/KG SBCAPE. ALTHOUGH THIS IS LIKELY TOO HIGH AS MODEL FORECAST DEW POINTS APPEAR TOO MOIST ACROSS THIS REGION. REGARDLESS...CAP REMOVAL AND FRONTAL CONVERGENCE SHOULD ALLOW CONVECTION TO DEVELOP SWD DURING THE AFTERNOON WITH TSTMS EXPECTED INTO NERN KS BY EARLY EVENING. THERE MAY BE SOME PROPENSITY FOR CONVECTION TO DEVELOP ALONG/JUST BEHIND THE COLD FRONT WITH SUBSEQUENT MOVEMENT IN RELATION TO ADVANCING COLD FRONT. IN FACT...DURING THE OVERNIGHT HOURS CONVECTION MAY DEVELOP AS FAR SOUTH AS THE KS/OK BORDER DESPITE THE VERY STRONG CAP THAT WILL BE IN PLACE MUCH OF THE PERIOD. THIS LATE NIGHT ACTIVITY WOULD CERTAINLY BE ELEVATED IN NATURE BUT COULD OTHERWISE PRODUCE HAIL GIVEN THE VERY MOIST/UNSTABLE AIRMASS THAT WILL BE IN PLACE ACROSS LOWER LATITUDES. GREATEST POTENTIAL FOR SUPERCELL STRUCTURES WILL OCCUR ALONG THE NRN SECTIONS OF THE COLD FRONT ACROSS MN AND IF UPDRAFTS CAN STAY ROOTED IN WARM SECTOR BOUNDARY LAYER THERE MAY BE A TORNADO OR TWO WITH ORGANIZED DISCRETE STRUCTURES. OTHERWISE IT APPEARS LARGE HAIL IS THE MAIN CONCERN WITH CONVECTION SUNDAY. ...CENTRAL GULF STATES... SLOW MOVING UPPER TROUGH IS EXPECTED TO LIFT NEWD ACROSS THE NRN GULF BASIN INTO THE CNTRL GULF STATES LATE IN THE PERIOD. THIS FEATURE HAS PRODUCED CONSIDERABLE AMOUNT OF CONVECTION OVER THE LAST DAY OR SO ACROSS THE NRN GULF AND IMMEDIATE GULF STATES. THERE IS REASON TO BELIEVE THAT WIDESPREAD SHOWERS AND THUNDERSTORMS WILL ONCE AGAIN DEVELOP ACROSS THIS REGION AS VERY MOIST PROFILES...PW VALUES ON THE ORDER OF 2 INCHES...AND WEAK WARM ADVECTION WILL PERSIST INTO EARLY MONDAY ACROSS THIS REGION. WILL MAINTAIN LOW PROBS FOR AN ISOLATED MOIST DOWNBURST OR PERHAPS EVEN A BRIEF WEAK TORNADO. ..DARROW/SMITH.. 06/10/2012
via SPC Forecast Products http://www.spc.noaa.gov/products/outlook/day1otlk_1200.html
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