SPC AC 180736
   
   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0236 AM CDT SAT JUN 18 2005
   
   VALID 201200Z - 211200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS MON/MONDAY NIGHT ACROSS PARTS
   OF MONTANA....
   
   ...NORTH CENTRAL STATES...
   MODELS SUGGEST AMPLIFIED UPPER FLOW PATTERN ALONG THE CENTRAL
   CANADIAN/U.S. BORDER WILL BECOME MORE ZONAL LATE TODAY THROUGH EARLY
   MONDAY.  THIS WILL OCCUR IN RESPONSE TO HEIGHT FALLS ASSOCIATED WITH
   A COUPLE OF SIGNIFICANT SHORT WAVES TROUGHS...ONE EMANATING FROM
   LARGE SCALE PACIFIC COAST TROUGH...THE OTHER MIGRATING AROUND
   WESTERN/SOUTHERN PERIPHERY OF POLAR LOW NORTH OF THE CANADIAN
   NORTHWEST TERRITORIES. MID DAY MONDAY INTO EARLY TUESDAY...LATTER
   SHORT WAVE TROUGH WILL PROGRESS EAST OF MANITOBA INTO ONTARIO...WITH
   UPPER RIDGE BEGINNING TO REBUILD ALONG AN AXIS EAST OF THE
   CANADIAN/NORTHERN U.S. ROCKIES.
   
   EVOLVING UPPER PATTERN APPEARS LIKELY TO MAINTAIN STRONG MID-LEVEL
   THERMAL RIDGE FROM THE MEXICAN PLATEAU AND SOUTHERN ROCKIES THROUGH
   MUCH OF THE DAKOTAS.  MEANWHILE...MODELS SEEM TO SUGGEST
   WEAK/WEAKENING CONVECTION EARLY IN THE PERIOD ACROSS THE NORTHERN
   PLAINS/UPPER MISSISSIPPI VALLEY MAY SUPPORT PROGRESSION OF EFFECTIVE
   SURFACE FRONT TO THE SOUTH OF STRONGER MID-LEVEL CAPPING. 
   THUS...CONSIDERABLE UNCERTAINTY EXISTS CONCERNING POTENTIAL FOR
   VIGOROUS CONVECTIVE DEVELOPMENT EAST OF THE NORTHERN HIGH PLAINS
   DURING THIS FORECAST PERIOD.
   
   BEST POTENTIAL FOR VIGOROUS CONVECTIVE DEVELOPMENT MONDAY MAY BE
   CONFINED TO MOIST UPSLOPE FLOW REGIME ACROSS MONTANA...WHERE DAYTIME
   HEATING WILL CONTRIBUTE TO STEEP LAPSE RATES AND MODERATE
   INSTABILITY.  BY PEAK HEATING...DIFLUENT UPPER FLOW REGIME LIKELY
   WILL BECOME FOCUSED ACROSS WEST CENTRAL MONTANA...TO THE WEST OF
   BUILDING RIDGE AXIS...WHERE SHEAR PROFILES BENEATH MODERATELY
   SOUTHWESTERLY MID-LEVEL FLOW WILL BE SUPPORTIVE OF ISOLATED
   SUPERCELLS.  WARM ADVECTION REGIME IN THE LEE OF THE NORTHERN
   ROCKIES MAY MAINTAIN STRONG/SEVERE STORMS INTO MONDAY
   EVENING...BEFORE ACTIVITY DIMINISHES WITH LOSS OF HEATING.
   
   ..KERR.. 06/18/2005
   
   ...NOTICE...
   THE STATION RELATIVE POINTS IN THIS PRODUCT ARE NOW AVAILABLE
   SEPARATELY UNDER THE WMO HEADINGS WUUS01 PTSDY1...
   WUUS02 PTSDY2...WUUS03 PTSDY3.  THE INCLUSION OF POINTS
   IN THIS DISCUSSION WILL BE DISCONTINUED AFTER THE 2005
   CONVECTIVE SEASON.  A PUBLIC NOTIFICATION STATEMENT (PNS)
   WILL PROVIDE DETAILS ON THE TRANSITION.
   
   CLICK TO GET WUUS03 PTSDY3 PRODUCT

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 1100Z