SPC AC 150702
   
   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0202 AM CDT THU SEP 15 2005
   
   VALID 171200Z - 181200Z
   
   ...NO SVR TSTM AREAS FORECAST...
   
   ...SYNOPSIS...
   A SERIES OF STRONG IMPULSES WILL TRANSLATE EWD FROM THE INTERIOR
   NORTHWEST TO THE NRN PLAINS/UPPER MS VALLEY DURING THE WEEKEND. THE
   LEAD SYSTEM SHOULD SPREAD EAST ALONG THE U.S./CANADA BORDER AND
   INDUCE SURFACE LOW DEVELOPMENT ALONG A STRONG FRONTAL ZONE FROM THE
   DAKOTAS INTO MN. AS THE LOW TRACKS NEWD INTO SRN ONTARIO...TRAILING
   COLD FRONT WILL SPREAD SEWD AND ENCOUNTER MODESTLY UNSTABLE AIR MASS
   FROM THE NCNTRL PLAINS TO THE UPPER MS VALLEY. MEANWHILE...AN
   OCCLUDED LOW IS FORECAST TO MOVE SLOWLY ACROSS THE NORTHEAST. THE
   FRONTAL ZONE ASSOCIATED WITH THIS SYSTEM WILL TRAIL SWD ALONG THE
   ERN SEABOARD.
   
   ...MO RIVER VALLEY TO MN...
   DESPITE GENERAL AGREEMENT AMONG LATEST GUIDANCE IN THE PLACEMENT AND
   MOVEMENT OF LARGE SCALE FEATURES ACROSS THE NRN PLAINS... DETAILS OF
   TIMING...STORM INITIATION...AND DEGREE OF INSTABILITY ARE NOT YET
   CLEAR. STRONG FORCING ALONG THE ADVANCING FRONT ACROSS THE ERN
   DAKOTAS AND NRN MN...IN THE PRESENCE OF AT LEAST MODEST
   INSTABILITY...WOULD SUGGEST SOME POTENTIAL FOR ORGANIZED SEVERE
   STORMS THIS AREA. WHILE LATEST NAM DEPICTS THIS SCENARIO...LATEST
   GFS IS FAR LESS AGGRESSIVE WITH CONVECTIVE QPF AND VERTICAL MOTION
   ACROSS THE REGION...AND SUGGESTS WARM SECTOR MAY REMAIN CAPPED.
   GIVEN THESE DIFFERENCES...IT IS TOO EARLY TO INTRODUCE A SLGT RISK
   ACROSS THE AREA.
   
   NAM ALSO SIGNALS THE DEVELOPMENT OF A COUPLE OF STORM COMPLEXES
   ACROSS IA AND MO THROUGH EARLY SUNDAY. THIS OCCURS PRIMARILY AFTER
   DARK AS SHORT WAVE IMPULSE CRESTS THE BROAD RIDGING ACROSS THESE
   AREAS AND INSTABILITY ON THE NOSE OF PLAINS LOW LEVEL JET IS
   RELEASED ON THE EDGE OF THE CAP. ISOLATED SEVERE WEATHER IN THE FORM
   OF HAIL FROM ELEVATED STORMS COULD DEVELOP ACROSS IA/MO THROUGH
   SATURDAY NIGHT IF THIS SCENARIO DOES OCCUR.
   
   ...MID ATLANTIC...
   SLOWER MOVEMENT OF THE COLD FRONT NEAR THE EAST COAST AS DEPICTED BY
   THE NAM IS PREFERRED OVER THE FASTER GFS IN THIS AREA.
   HOWEVER...CONSIDERABLE UNCERTAINTY REMAINS WITH REGARD TO THE
   INTERACTION OF THE FRONT AND THE OCCLUDING CYCLONE OVER THE
   NORTHEAST...AND INFLUX OF TROPICAL AIR MASS ASSOCIATED WITH OPHELIA.
   LATEST NAM DOES INDICATE THE POTENTIAL FOR A WEAK WAVE TO DEVELOP
   ALONG FRONT/LEE TROUGH OVER THE NC/VA PIEDMONT SATURDAY AFTERNOON.
   THIS PERTURBATION THEN TRACKS NEWD INTO INCREASINGLY UNSTABLE AIR
   MASS ACROSS THE DELMARVA REGION AND SRN NJ. A FEW STRONG TO SEVERE
   STORMS ARE POSSIBLE IF THIS SCENARIO IS CORRECT.
   
   ..CARBIN.. 09/15/2005
   
   ...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