SPC Jul 15, 2012 1730 UTC Day 2 Convective Outlook

SPC 1730Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CDT SUN JUL 15 2012 VALID 161200Z - 171200Z ...NO SVR TSTM AREAS FORECAST... ...UPPER MS VALLEY/NRN PLAINS... A SUBTLE UPPER-LEVEL RIDGE WILL BE IN PLACE MONDAY ACROSS THE UPPER MS VALLEY WITH WEST TO NORTHWEST FLOW LOCATED TO THE NORTH OF THE RIDGE. AT THE SFC...A LOW WILL MOVE QUICKLY EWD ACROSS NRN MN AS A TRAILING COLD FRONT ADVANCES SEWD ACROSS THE NRN PLAINS AND UPPER MS VALLEY. THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE ALONG THE BOUNDARY DURING THE LATE AFTERNOON AS LOW-LEVEL CONVERGENCE INCREASES AND A CAPPING INVERSION TEMPORARILY WEAKENS. FORECAST SOUNDINGS IN CNTRL MN AND NRN WI AT 00Z/TUE GENERALLY SHOW MLCAPE IN THE 1500 TO 2500 J/KG RANGE WITH 0-6 KM SHEAR FROM 30 TO 40 KT RANGE SUGGESTING ORGANIZED STORMS WILL BE POSSIBLE. SWLY UNIDIRECTIONAL WINDS IN THE LOW TO MID-LEVELS WITH 30 TO 40 KT OF FLOW AROUND 850 MB SHOULD BE SUFFICIENT FOR AN ISOLATED WIND DAMAGE THREAT. HOWEVER...TEMPS ALOFT ARE FORECAST TO BE VERY WARM IN THE UPPER MS VALLEY AND LARGE-SCALE ASCENT SHOULD REMAIN WEAK DUE TO THE UPPER-LEVEL RIDGE. FOR THIS REASON...CONVECTIVE COVERAGE AND THE RESULTANT SEVERE THREAT SHOULD REMAIN ISOLATED ESPECIALLY WSWWD ALONG THE BOUNDARY INTO THE NRN PLAINS. THE EXCEPTION COULD BE ACROSS LAKE SUPERIOR AND UPPER MI WHERE THE GFS AND NAMKF DEVELOP A LINE OF STORMS MONDAY EVENING. INSTABILITY IS FORECAST TO DROP OFF NEWD ACROSS THE WRN GREAT LAKES REGION SUGGESTING ANY SEVERE THREAT SHOULD REMAIN ISOLATED THERE AS WELL. ...PACIFIC NORTHWEST/NRN ROCKIES... AN UPPER-LEVEL LOW WILL REMAIN NEARLY STATIONARY ACROSS NW ORE ON MONDAY. AT THE SFC...AN INVERTED SFC TROUGH SHOULD BE IN PLACE EXTENDING NWD FROM A SFC LOW OVER SE ORE. SEVERAL MODEL FORECASTS DEVELOP A POCKET OF MODERATE INSTABILITY TO THE EAST OF THE SFC TROUGH MONDAY AFTERNOON WITH SCATTERED THUNDERSTORMS INITIATING AS SFC TEMPS WARM. FORECAST SOUNDINGS AT 21Z IN THE PACIFIC NORTHWEST PLACE THE GREATEST INSTABILITY ACROSS NCNTRL ID WHERE MLCAPE VALUES SHOULD REACH 1000 TO 1500 J/KG MONDAY AFTERNOON. THE INSTABILITY COMBINED WITH 0-6 KM SHEAR IN THE 25 TO 35 KT RANGE AND LAPSE RATES AROUND 8.5 C/KM SHOULD BE SUFFICIENT FOR A MARGINAL SEVERE THREAT. A THREAT FOR HAIL AND STRONG GUSTS WILL BE MOST LIKELY WITH CELLS THAT HAVE ACCESS TO MODERATE INSTABILITY DURING THE LATE AFTERNOON. ..BROYLES.. 07/15/2012 Read more

http://www.spc.noaa.gov/products/outlook/day2otlk_1730.html