036 FXUS01 KWBC 071930 PMDSPD SHORT RANGE FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 229 PM EST SAT NOV 07 2009 VALID 00Z SUN NOV 08 2009 - 12Z MON NOV 09 2009 ONSHORE FLOW AHEAD OF THE NEXT STORM SYSTEM WILL PRODUCE SCATTERED LIGHT RAIN AND HIGHER ELEVATION SNOW ACROSS PORTIONS OF THE PACIFIC NORTHWEST AND THE NORTHERN INTERMOUNTAIN REGION THROUGH SUNDAY. BY SUNDAY EVENING ... THE APPROACHING FRONTAL SYSTEM WILL AID IN CONTINUING THE LIGHT RAIN AND THE HIGHER ELEVATION SNOW OVER PORTIONS OF THE PACIFIC NORTHWEST. MEANWHILE ... A FRONT EXTENDING FROM THE GREAT LAKES SOUTHWESTWARD TO THE CENTRAL ROCKIES WILL DEVELOP A WAVE OF LOW PRESSURE THAT WILL ADVANCE ALONG THE BOUNDARY FROM THE CENTRAL HIGH PLAINS TO THE GREAT LAKES BY MONDAY. THE SYSTEM WILL HAVE VERY LITTLE MOISTURE TO WORK WITH THROUGH SUNDAY EVENING WHEN FLOW OFF THE WESTERN GULF COAST WILL POOL MORE MOISTURE ALONG THE BOUNDARY. WITH THE ADDITIONAL MOISTURE ... SCATTERED LIGHT SHOWERS AND EMBEDDED THUNDERSTORMS WILL FORM OVER PARTS OF THE UPPER MIDWEST AND CENTRAL PLAINS. THE WAVE OF LOW PRESSURE WILL BRING ABOVE TO MUCH ABOVE AVERAGE TEMPERATURES TO THE MIDDLE MISSISSIPPI VALLEY TO THE UPPER GREAT LAKES. UPPER LEVEL ENERGY OVER NORTHERN MEXICO IN COMBINATION WITH MOISTURE FLOWING NORTHWARD OFF THE GULF OF MEXICO WILL TRIGGER SHOWERS AND THUNDERSTORMS OVER THE WESTERN AND CENTRAL GULF COAST STARTING SUNDAY MORNING GOING THROUGH MONDAY. ZIEGENFELDER GRAPHIC AVAILABLE AT WWW.HPC.NCEP.NOAA.GOV $$