000 AXPZ20 KNHC 291003 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC THU OCT 29 2009 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0915 UTC. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE WAS ALONG THE LINE FROM 11N74W TO 11N82W TO 15N101W TO 11N107W TO 12N115W TO 10.5N129W TO 09N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 120 NM S AND 90 NM N OF AXIS E OF 98W. ISOLATED TO SCATTERED MODERATE CONVECTION WAS WITHIN 90 NM S AND 120 NM N OF AXIS W OF 103W. OTHER CONVECTION WAS NOTED...SCATTERED MODERATE TO STRONG FROM 10N TO 18N BETWEEN 98.5W AND 102.5W AND LOOSELY ASSOCIATED WITH LOW NEAR 16.5N103W. ISOLATED TO SCATTERED MODERATE WITHIN 120 NM OF COASTLINE BETWEEN 88W AND 97W. ...DISCUSSION... DEEP LAYERED LONGWAVE TROUGH ACROSS WRN N AMERICA HAS SHARPENED EVEN FURTHER PAST 24 HOURS...AND WAS ALONG 108/109W TO AN UPPER LOW OVER THE FOUR CORNERS REGION...WITH BASE OF TROUGH EXTENDING TO 23N116W. BROAD MID TO UPPER TROUGHING CONTINUES TO EXTEND FROM THIS FEATURE...SW TO A SYNOPTIC SCALE MID LEVEL LOW NEAR 14N136W...WHICH CONTINUE TO SHIFT WSW AND ELONGATE THE CONNECTING TROUGH. THE LONGWAVE TROUGH IS FORECAST TO BEGIN TO SHIFT E ACROSS THE U.S. TONIGHT AND LIFT UP AND OVER A FLATTENING RIDGE ACROSS THE GLFMEX AND SE U.S. THROUGH MONDAY. THIS WILL LEAVE A TUTT EXTENDING FROM THE W COAST OF MEXICO ALONG 25/26N...WSW ACROSS THE FORECAST AREA TO THE MID LEVEL/TUTT LOW. TO THE W OF THESE TROUGHS LIES A VERY SHARP UPPER RIDGE EXTENDING FROM A HIGH OVER THE ITCZ NEAR 10N157W...NNE INTO THE FAR NE PACIFIC BETWEEN 150W AND 135W. AT LOWER LEVELS...THE SHARPENING LONG WAVE TROUGH ACROSS THE WRN U.S. HAS ALLOWED FOR A STRONG NLY FLOW TO DIVE ALONG THE W COAST OF THE U.S. AND INTO THE N HALF OF THE FORECAST AREA...USHERING A WEAK FRONTAL BOUNDARY S THROUGH MOST OF THE BAJA PENINSULA AND GULF OF CALIFORNIA TO S PORTIONS OF BAJA...EXTENDING WSW AND BECOMING DIFFUSE OVER THE SUBTROPICAL PACIFIC. MID TO UPPER LEVEL CONVERGENCE N OF 16N W OF 120W CONTINUES TO PRODUCE STRONG SUBSIDENCE AND VERY STABLE AIR ACROSS THIS AREA...WITH BROKEN TO OVERCAST STRATOCUMULUS DOMINATING. GALES OCCURRING BETWEEN A 1029 MB HIGH NEAR 36N136W AND THE CALIFORNIA COAST CONTINUE THIS MORNING...S TO 30N...WITH OVERNIGHT SCATTEROMETER PASSES INDICATING 25-30 KT NLY WINDS N OF 27N E OF 127W...WHERE SEAS WHERE FORECAST BY WWIII TO BE 12 TO 17 FT IN A BROAD SPECTRAL MIX OF N AND NW SWELL. NELY TRADES OF 20-25 KT S OF THE HIGH AND ASSOCIATED RIDGE EXTENDED S TO THE ITCZ W OF 125W. THE COLD AIR ADVECTION AND PRESSURE GRADIENT INDUCED BY THIS SYNOPTIC PATTERN WILL GRADUALLY RELAX OVER THE NEXT 12 TO 48 HOURS AS THE TROUGH SHIFTS E ACROSS THE U.S. WHICH WILL CAUSE THE FRESH NELY TRADES TO SHIFT W OF 130W BY SAT. THE MIX OF NLY AND NW SWELL FROM THIS EVENT WILL PUSH 8 FT SEAS S AND SE AND CROSS 10N SATURDAY MORNING...WITH SEAS SUBSIDING N OF 20N TO LESS THAN 8 FT. E OF 110W...AN UPPER RIDGE CONTINUES FROM THE ITCZ ALONG 105W...NE ACROSS THE SE GLFMEX...WHILE A TUTT LOW HAS GRADUALLY RETROGRADED SW INTO THE SW CARIBBEAN ALONG 79W. DIFFLUENCE ALOFT INDUCED BY THIS PATTERN IS MAINTAINING ACTIVE CONVECTION ACROSS THIS PORTION OF THE EPAC...AS THE MONSOONAL GYRE DOMINATES E OF 110W. AN ELONGATED TROUGH CONTINUES THIS MORNING FROM A BROAD LOW NEAR 17N103W...ESE TO THE ITCZ ALONG 90W. STRONG SWLY SHEAR OCCURRING IN THE BASE OF THE L/W TROUGH ACROSS THE U.S. HAS BEEN SHEARING CONVECTION AND MOISTURE ACROSS THE REGION TO THE NE FOR THE PAST FEW DAYS. HOWEVER...AS THE TROUGH SHIFTS E AND LIFTS OUT OVER THE WEEKEND...GLOBAL MODELS RESPOND BY SUGGESTING THE OPPORTUNITY FOR BETTER ORGANIZATION OF A LOW ACROSS THIS AREA...WITH POTENTIAL FOR TROPICAL CYCLOGENESIS BETWEEN 90W AND 105W OVER THE NEXT SEVERAL DAYS. GOOD INFLOW OF 20-25 KT INTO THE S SIDE OF THIS CYCLONIC GYRE WILL CONTINUE S OF THE ITCZ DURING THE NEXT FEW DAYS...MAINTAINING SEAS AROUND 8 FT. LOOK FOR THIS GYRE AND AREA OF ACTIVE CONVECTION TO LIFT FURTHER N AND WITHIN A FEW DEGREES OF THE COAST OF SRN MEXICO AND THE REMAINDER OF CENTRAL AMERICA. $$ STRIPLING