SPC 0600Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1259 AM CDT SAT JUN 09 2012 VALID 101200Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MS VALLEY TO NRN OK... ...SYNOPSIS... LARGE-SCALE UPPER-LEVEL TROUGH EXPECTED TO BE CENTERED INVOF THE PRAIRIE PROVINCES TO THE CNTRL ROCKIES AT 12Z/SUN WILL GRADUALLY PROGRESS E/NEWD ACROSS S-CNTRL CANADA INTO THE UPPER MS VALLEY BY EARLY MON AS AN EMBEDDED SHORT WAVE IMPULSE ROTATES NEWD ACROSS THE DAKOTAS DURING THE DAY ON SUN. THIS WILL AID IN DEEPENING OF A SURFACE CYCLONE INVOF SERN MANITOBA/NWRN ONTARIO...ESPECIALLY DURING THE LATTER HALF OF THE PERIOD. ASSOCIATED SURFACE COLD FRONT WILL ACCELERATE EWD ACROSS THE UPPER MIDWEST...WITH TRAILING PORTION SINKING MORE S/SEWD FROM THE MID-MO VALLEY TO THE CNTRL/SRN HIGH PLAINS. ...UPPER MS VALLEY TO KS/OK... SCATTERED TO NUMEROUS TSTMS ARE EXPECTED ALONG MUCH OF THE COLD FRONT ON D2 AS 60S SURFACE DEW POINTS BECOME PREVALENT IN A CORRIDOR AHEAD OF THE FRONT. SEVERE THREAT SHOULD COMMENCE INITIALLY IN THE UPPER MS VALLEY...AHEAD OF A TSTM CLUSTER OR TWO THAT MAY BE ONGOING IN THE ERN DAKOTAS AT 12Z/SUN. WITH DIURNAL HEATING...ADDITIONAL TSTMS WILL LIKELY FORM WITHIN THE FRONTAL ZONE BY EARLY/MID-AFTERNOON AS MID-LEVEL DCVA INCREASES AHEAD OF THE DAKOTAS SHORT WAVE IMPULSE. ALTHOUGH THE BULK OF FAST MID-LEVEL S/SWLYS SHOULD LAG THE FRONT...INTENSIFYING FLOW AT 700 MB TO AOA 50 KT WILL RESULT IN ORGANIZED CLUSTERS/LINE SEGMENTS CAPABLE OF ALL SEVERE TYPES /ESPECIALLY FROM CNTRL MN NWD TO THE CANADIAN BORDER/. WITH SOME UNCERTAINTY OVER THE DEGREE OF DESTABILIZATION GIVEN POTENTIAL LINGERING OF OVERNIGHT CONVECTION FROM D1...ALONG WITH DEEP-LAYER FLOW ORIENTED NEARLY PARALLEL TO THE FRONT...A MODERATE RISK DOES NOT APPEAR WARRANTED ATTM. FARTHER S/SW FROM THE MID-MO VALLEY INTO THE CNTRL/SRN PLAINS...MID/UPPER-LEVEL FLOW WILL BE WEAKER WITH SRN EXTENT AND LARGELY PARALLEL TO THE ORIENTATION OF THE SURFACE FRONT. STILL...A STRONGLY UNSTABLE AIR MASS AHEAD OF THE FRONT IN KS/OK SHOULD YIELD A RISK FOR LARGE HAIL AND SEVERE WIND. CONVERGENCE/WAA ATOP THE FRONTAL ZONE SHOULD AID IN MAINTAINING TSTM CLUSTERS SUN NIGHT...WITH AN INCREASINGLY MARGINAL SEVERE RISK. ...CNTRL GULF COAST... A WEAK MID-LEVEL IMPULSE OFF THE WRN GULF COAST SHOULD SLOWLY MEANDER NEWD TOWARDS THE LOWER MS VALLEY ON SUN. GUIDANCE IS FAIRLY CONSISTENT WITH INDICATING AN ENHANCEMENT TO DEEP S/SWLY FLOW WILL OCCUR DOWNSTREAM OF THIS IMPULSE...ALTHOUGH THEY VARY WITH AMPLITUDE. DESPITE POOR MID-LEVEL LAPSE RATES...WITH A RICH PW AIR MASS /AROUND 2 IN/...IT IS PLAUSIBLE THAT A FEW WEAKLY ORGANIZED STORMS MAY EVOLVE DURING THE DIURNAL HEATING CYCLE. PRIMARY THREATS SHOULD BE LOCALLY DAMAGING WINDS AND PERHAPS A BRIEF TORNADO. ..GRAMS.. 06/09/2012
via SPC Forecast Products http://www.spc.noaa.gov/products/outlook/day2otlk_0600.html
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