SPC AC 220558
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1258 AM CDT MON OCT 22 2012
   
   VALID 231200Z - 241200Z
   
   ...NO SVR TSTM AREAS FORECAST...
   
   ...SYNOPSIS...
   LARGE SCALE PATTERN AMPLIFICATION WILL CONTINUE TO OCCUR ON
   TUESDAY...HIGHLIGHTED BY AN INCREASINGLY PROMINENT WESTERN STATES
   LONGWAVE TROUGH. A MIGRATORY SHORTWAVE TROUGH AND WARM ADVECTION
   REGIME WILL CONTRIBUTE TO TSTM POTENTIAL ACROSS THE MIDDLE/UPPER MS
   VALLEY AND GREAT LAKES REGION...BUT GRADUALLY RISING UPPER HEIGHTS
   ARE OTHERWISE ANTICIPATED OVER THE MIDWEST/GREAT LAKES REGION.
   
   ...MIDDLE/UPPER MS VALLEY AND GREAT LAKES...
   GIVEN THE LARGE SCALE SCENARIO AS PREVIOUSLY DESCRIBED...A SHORTWAVE
   TROUGH IS EXPECTED TO WEAKEN AS IT SPREADS EAST-NORTHEASTWARD TOWARD
   THE MIDDLE MS VALLEY/OH VALLEY ON TUESDAY. A WARM ADVECTION REGIME
   WILL OTHERWISE ACCOUNT FOR SOME TSTMS ACROSS THE LOWER GREAT LAKES
   REGION DURING THE PERIOD.
   
   ACROSS PARTS OF IA/NORTHERN MO INTO ADJACENT SOUTHERN MN/SOUTHERN WI
   AND NORTHERN IL...WITHIN A RELATIVELY MOIST/POTENTIALLY UNSTABLE
   AIRMASS NEAR A WEAKENING SURFACE LOW AND/OR WARM FRONT...THE
   POTENTIAL FOR DIURNAL SURFACE BASED CONVECTION CURRENTLY APPEARS
   LOW. THIS IS ATTRIBUTABLE TO THE POTENTIAL FOR CAPPING /PERHAPS
   UNDER REFLECTED BY 00Z NAM GUIDANCE/ AND LITTLE OR NO READILY
   DISCERNIBLE BROAD SCALE ASCENT AND MODEST MASS CONVERGENCE. OF MORE
   POTENTIAL WILL BE FOR ELEVATED CONVECTION TO INCREASE TUESDAY NIGHT
   TO THE NORTH OF A NORTHWARD-SHIFTING WARM FRONT ACROSS THE UPPER
   MIDWEST/UPPER MS VALLEY. SOME SEVERE HAIL CANNOT BE RULED OUT IN
   THIS SCENARIO GIVEN THE PROXIMITY OF A RELATIVELY MOIST/POTENTIALLY
   UNSTABLE AIRMASS. WHILE SCENARIO UNCERTAINTY AND SEEMINGLY LIMITED
   POTENTIAL PRECLUDES SEVERE PROBABILITIES AT THIS TIME...PORTIONS OF
   THE UPPER MS RIVER VALLEY WILL BE REEVALUATED IN SUBSEQUENT OUTLOOKS
   FOR SOME SEVERE RISK. 
   
   ...COASTAL ORE/NORTHERN CA...
   COINCIDENT WITH RELATIVELY STEEP LAPSE RATES...ISOLATED/EMBEDDED
   LOW-TOPPED TSTMS WILL BE POSSIBLE FOR COASTAL AREAS AND PERHAPS
   PORTIONS OF INTERIOR NORTHERN CA ON TUESDAY. THIS WILL BE WITHIN THE
   POST-FRONTAL ENVIRONMENT IN THE WAKE OF AN INITIAL  FRONT...AND/OR
   NEAR AN APPROACHING SECONDARY FRONT/TROUGH LATE IN THE PERIOD. WHILE
   SOME SMALL HAIL MAY BE POSSIBLE...ORGANIZED/SUSTAINED SEVERE TSTMS
   ARE UNLIKELY GIVEN  MEAGER INSTABILITY AND THE LOW-TOPPED NATURE OF
   THE CONVECTION.
   
   ..GUYER.. 10/22/2012
   
   CLICK TO GET WUUS02 PTSDY2 PRODUCT

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z