Categorical Graphic
Probabilistic Tornado Graphic
Probabilistic Damaging Wind Graphic
Probabilistic Large Hail Graphic

   SPC AC 150548
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1248 AM CDT SUN JUN 15 2008
   
   VALID 151200Z - 161200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS TODAY ACROSS A LARGE PORTION OF
   THE S CNTRL PLAINS INTO THE SRN GREAT LAKES...INCLUDING MUCH OF NRN
   OKLAHOMA...CNTRL/ERN KANSAS...MUCH OF NRN/WRN MISSOURI...NRN/CNTRL
   ILLINOIS...NRN INDIANA...LWR MI AND NW OHIO....
   
   ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK
   AREA...ACROSS THE CNTRL/SRN PLAINS...MID MS/OH VLYS AND SRN GREAT
   LAKES REGION....
   
   ...SYNOPSIS...
   THE MID-LEVEL CIRCULATION CENTER NOW NEAR SOUTHERN HUDSON BAY IS
   FORECAST TO REDEVELOP SOUTH SOUTHEASTWARD TOWARD THE UPPER GREAT
   LAKES REGION DURING THIS PERIOD.  MODELS SUGGEST THAT THIS WILL
   OCCUR AS PHASING SHORT WAVE IMPULSES...WITHIN A BROAD CYCLONIC FLOW
   REGIME TO ITS SOUTH/EAST...DIG THROUGH THE GREAT LAKES.  AT THE SAME
   TIME...A SUBTROPICAL HIGH CENTER IS PROGGED TO REMAIN STRONG ACROSS
   THE SOUTHERN PLATEAU/SOUTHERN ROCKIES INTO THE NORTHERN MEXICAN
   PLATEAU...WHILE A RIDGE AXIS BUILDS NORTHWARD THROUGH THE
   ROCKIES...AHEAD OF ANOTHER CLOSED LOW/TROUGH DIGGING WEST OF THE
   BRITISH COLUMBIA COAST.  
   
   IN RESPONSE TO THE EVOLVING PATTERN...SEASONABLY MODERATE TO STRONG
   WEST/NORTHWESTLY UPPER FLOW IS EXPECTED TO DEVELOP TODAY ACROSS MUCH
   OF THE CENTRAL/NORTHERN PLAINS...EASTWARD THROUGH THE OHIO VALLEY
   AND GREAT LAKES REGION.  THIS IS PROGGED TO BE COUPLED WITH THE
   PRESENCE OF STEEP LAPSE RATES THROUGH A DEEP LAYER OF THE LOWER/MID
   TROPOSPHERE...OVER A FAIRLY BROAD AREA FROM THE NORTHEASTERN
   PERIPHERY OF THE SUBTROPICAL RIDGE THROUGH THE BASE OF THE GREAT
   LAKES TROUGH.  AND...THIS ENVIRONMENT WILL BE CONDUCIVE FOR AN
   OUTBREAK OF SEVERE STORMS...INCLUDING SEVERAL STORM CLUSTERS CAPABLE
   OF PRODUCING HAIL AND SWATHS OF STRONG DAMAGING WINDS.
   
   ...CNTRL PLAINS THRU THE MID MS VLY AND SRN GREAT LAKES REGION...
   WHILE THE LOW-LEVEL ENVIRONMENT THROUGH MUCH OF THE CENTRAL/
   SOUTHERN PLAINS REMAINS VERY WARM...SOME OF THIS AIR IS BEGINNING TO
   ADVECT EASTWARD ALONG THE SOUTHERN FRINGE OF THE STRONGER
   WESTERLIES...TOWARD THE LOWER GREAT LAKES REGION.  MODEL GUIDANCE IS
   IN GENERAL AGREEMENT SUGGESTING THAT A PRE-FRONTAL THERMAL RIDGE
   WILL EXTEND FROM NEAR THE KANSAS/NEBRASKA BORDER EASTWARD THROUGH
   SOUTHERN LOWER MICHIGAN BY MID DAY.  AND...THIS FEATURE IS EXPECTED
   TO PROVIDE AT LEAST ONE FOCUS...PERHAPS THE MAIN FOCUS...FOR STORM
   INITIATION.
   
   FORCING ASSOCIATED WITH IMPULSES ON THE SOUTHERN FRINGE OF THE
   AMPLIFYING GREAT LAKES TROUGH SHOULD CONTRIBUTE TO STORM
   DEVELOPMENT.  AT LEAST ONE CLUSTER APPEARS LIKELY ACROSS THE
   SOUTHERN GREAT LAKES REGION DURING THE DAY.  WHILE LOW-LEVEL
   MOISTURE MAY NOT BE OPTIMAL ACROSS THIS REGION...STEEP LAPSE RATES
   ...LOW SUB-CLOUD BASE RELATIVE HUMIDITIES...AND 30-50 KT MEAN CLOUD
   BEARING LAYER FLOW SHOULD CONTRIBUTE TO DAMAGING WIND POTENTIAL. 
   AND...MIXED LAYER CAPE OF 1000-2000 J/KG WILL PROBABLY ALSO BE
   SUPPORTIVE OF LARGE HAIL.
   
   FARTHER TO THE SOUTH/WEST...ON THE EDGE OF A WARMER/STRONGER CAPPING
   MID-LEVEL ENVIRONMENT...MODELS INDICATE A RETURN OF HIGHER MOISTURE
   CONTENT AIR INTO PARTS OF THE EAST CENTRAL PLAINS AND LOWER MISSOURI
   VALLEY.  THIS IS PROGGED TO BE SUPPORTIVE OF MIXED LAYER CAPE IN
   EXCESS OF 3000 J/KG...FAVORABLE FOR INTENSE UPDRAFTS  CAPABLE OF
   PRODUCING VERY LARGE HAIL...IN THE PRESENCE OF AT LEAST WEAK TO
   MODERATE SHEAR BENEATH MODEST NORTHWEST MID-LEVEL FLOW.  
   
   IT IS STILL UNCERTAIN WHETHER THE SEVERE THREAT WILL INCREASE FROM
   AN INTENSIFICATION OF EARLY MORNING STORMS OVER THE MID MISSOURI
   VALLEY...OR NEW DEVELOPMENT DURING THE MIDDAY HOURS.  BUT...A STRONG
   SIGNAL EXISTS IN MODEL DATA FOR THE EVOLUTION OF A LARGE MESOSCALE
   CONVECTIVE SYSTEM ACROSS EASTERN KANSAS INTO WESTERN/ NORTHERN
   MISSOURI.  AS AN ASSOCIATED SURFACE COLD POOL STRENGTHENS ...THE
   NORTHWESTLY MID-LEVEL FLOW COMPONENT WILL AID SOUTHEASTWARD
   /SOUTHWARD PROPAGATION TOWARD THE SOUTH CENTRAL PLAINS/OZARK
   PLATEAU...WHERE A SOUTHERLY LOW-LEVEL JET MAY CONTRIBUTE TO SYSTEM
   ACCELERATION LATE THIS AFTERNOON AND EVENING.  WIDESPREAD DAMAGING
   WIND GUSTS ARE POSSIBLE...WITH EMBEDDED SWATHS OF STRONG TO VERY
   STRONG GUSTS.
   
   MODELS ARE SUGGESTIVE THAT A SIGNIFICANT IMPULSE MIGRATING AROUND
   THE SUBTROPICAL RIDGE COULD CONTRIBUTE TO ANOTHER POSSIBLE STORM
   CLUSTER ACROSS THE SOUTH CENTRAL HIGH PLAINS INTO THE RED RIVER
   VALLEY LATE THIS AFTERNOON AND EVENING.  AND...MERGING/
   CONSOLIDATING STORM CLUSTERS COULD YIELD AN EXPANSIVE AREA OF
   CONVECTION BY TONIGHT FROM THE SOUTH CENTRAL PLAINS INTO AREAS
   NEAR/NORTH OF THE OHIO RIVER...WHERE GUSTY WINDS MAY REMAIN A RISK
   INTO EARLY MONDAY MORNING.
   
   ..KERR/JEWELL.. 06/15/2008
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z