Jun 19, 2010 0600 UTC Day 1 Convective Outlook
Updated: Sat Jun 19 05:53:45 UTC 2010
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20100619 1200 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20100619 1200 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20100619 1200 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20100619 1200 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 190550
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1250 AM CDT SAT JUN 19 2010
   
   VALID 191200Z - 201200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTN AND EVEN ACROSS PARTS
   OF THE UPPER OHIO VALLEY/LOWER GREAT LAKES REGION...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTN AND TONIGHT
   ACROSS THE NORTH CENTRAL PLAINS...
   
   ...SYNOPSIS...
   SUBTROPICAL RIDGING...CENTERED NEAR OR JUST INLAND OF THE
   WESTERN/CENTRAL GULF COAST...APPEARS LIKELY TO REMAIN STRONG THROUGH
   THIS FORECAST PERIOD...ENCOMPASSING MUCH OF THE CENTRAL AND SOUTHERN
   TIER OF THE U.S. TO THE EAST OF THE ROCKIES.  WITHIN THE PERSISTENT
   LARGE-SCALE UPPER TROUGH OVER THE WEST...MODELS INDICATE THAT A
   SIGNIFICANT CLOSED LOW WILL CONTINUE DIGGING INLAND ACROSS THE NORTH
   CENTRAL PACIFIC COAST.  MEANWHILE...A SERIES OF JET STREAKS
   EMANATING FROM THE SUBTROPICAL PACIFIC IS PROGGED TO CONTINUE INLAND
   THROUGH THE BASE OF THE TROUGH ACROSS SOUTHERN CALIFORNIA...BEFORE
   NOSING AROUND THE WESTERN AND NORTHERN PERIPHERY OF THE UPPER RIDGE.
    AS THIS OCCURS...REMNANT SHORT WAVE TROUGHING WITHIN THE SOUTHERN
   BRANCH OF CONFLUENT BELTS OF WESTERLIES NEAR/NORTH OF THE
   CANADIAN/U.S. BORDER IS EXPECTED MIGRATE EAST OF THE UPPER GREAT
   LAKES.  DOWNSTREAM OF BROADER SCALE RIDGING...THIS LATTER FEATURE
   MAY SUBTLY DIG TOWARD THE NORTHEASTERN U.S. LATE THIS AFTERNOON AND
   TONIGHT.
   
   ...LOWER OH/TN VALLEYS AND NRN GULF STATES INTO THE NORTHEAST...
   A REMNANT OUTFLOW BOUNDARY ASSOCIATED WITH ONGOING CONVECTION IS
   EXPECTED TO ADVANCE SOUTHEASTWARD THROUGH THE REMAINDER OF THE
   NIGHT...A BIT MORE RAPIDLY INTO/THROUGH THE LOWER OHIO VALLEY THAN
   THE LOWER MISSOURI/MID MISSISSIPPI VALLEY REGION.  THIS WILL
   PROBABLY SLOW...IF NOT CUT OFF...BETTER RETURN FLOW OF MOISTURE FROM
   THE SOUTH CENTRAL STATES...BUT SUFFICIENT MOISTENING IS EXPECTED
   AHEAD OF A COLD FRONT ADVANCING ACROSS SOUTHEASTERN CANADA AND THE
   LOWER GREAT LAKES TO CONTRIBUTE TO WEAK TO MODERATE INSTABILITY BY
   LATE AFTERNOON.  DESTABILIZATION IN THE PRESENCE OF 30-40+ KT DEEP
   LAYER SOUTHWESTERLY MEAN FLOW AHEAD OF THE APPROACHING UPPER TROUGH
   PROBABLY WILL BE SUFFICIENT FOR SCATTERED VIGOROUS STORM
   DEVELOPMENT.  A FEW SEVERE STORMS ARE POSSIBLE... PARTICULARLY TO
   THE LEE OF THE LOWER GREAT LAKES DURING THE LATE AFTERNOON AND
   EVENING...BUT PERHAPS ALSO ACROSS THE INTERNATIONAL BORDER INTO
   NORTHERN NEW ENGLAND DURING THE EVENING HOURS.
   
   FARTHER WEST AND SOUTHWEST...FORCING FOR NEW CONVECTIVE DEVELOPMENT
   ALONG THE STALLING/WEAKENING OUTFLOW BOUNDARY DURING THE DAY IS
   UNCLEAR.  IT MAY BE THAT REMNANT MESOSCALE CONVECTIVE VORTICES
   CONTINUE SOUTHEASTWARD...AND CONTRIBUTE TO NEW CONVECTION IN WEAKLY
   CAPPED MOIST/UNSTABLE AIR SOUTH OF THE OHIO RIVER INTO PARTS OF THE
   NORTHERN GULF STATES AND OZARK PLATEAU.  THOUGH WELL SOUTH OF THE
   STRONGER WESTERLIES...THERMODYNAMIC PROFILES MAY BE CONDUCIVE TO
   LOCALIZED DOWNBURSTS IN STRONGER STORMS.
   
   ...CENTRAL PLAINS...
   GREATER SEVERE POTENTIAL TODAY SEEMS TO EXIST NEAR A STALLING...
   EAST-WEST FRONTAL ZONE ACROSS THE CENTRAL PLAINS.  VERY WARM
   ELEVATED MIXED LAYER AIR WILL PROVIDE STRONG CAPPING...WHICH MAY
   PRECLUDE CONVECTIVE ACTIVITY TO THE SOUTH OF THE FRONT.  BUT
   MOISTENING ON EASTERLY LOW-LEVEL FLOW ALONG AND NORTH OF THE SURFACE
   FRONT INTO THE FRONT RANGE OF THE ROCKIES IS EXPECTED TO CONTRIBUTE
   TO MODERATE TO STRONG DESTABILIZATION BY LATE AFTERNOON.  
   
   STEEP MID-LEVEL LAPSE RATES AND MIXED LAYER CAPE OF 2000-3000+ J/KG
   WILL PROVIDE A FAVORABLE ENVIRONMENT FOR INTENSE STORMS...WHICH
   SHOULD INITIATE OFF THE HIGHER TERRAIN BY PEAK AFTERNOON HEATING. 
   STORM INITIATION ALSO APPEARS PROBABLE PRIOR TO 20/00Z ON THE NOSE
   OF A MODEST SOUTHERLY LOW-LEVEL JET ACROSS SOUTH CENTRAL NEBRASKA. 
   ALTHOUGH WESTERLY MID/UPPER FLOW NEAR THE FRONT MAY ALSO BE
   RELATIVELY MODEST...PRONOUNCED VEERING WITH HEIGHT NORTH OF THE
   FRONT WILL YIELD STRONG VERTICAL SHEAR.  THE ENVIRONMENT IS EXPECTED
   TO PROVE FAVORABLE FOR SUPERCELLS TRANSITIONING TO ONE OR MORE
   ORGANIZED MESOSCALE CONVECTIVE SYSTEMS...CAPABLE OF GENERATING
   ISOLATED VERY LARGE HAIL... EVENTUALLY AT LEAST LOCALIZED VERY
   STRONG WIND GUSTS.  STRONG WIND GUSTS AND HAIL MAY PERSIST WITH
   CONVECTION THROUGH THE EVENING...AND INTO OVERNIGHT HOURS.
   
   ..KERR/HURLBUT.. 06/19/2010
   
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