000 AXPZ20 KNHC 151011 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC THU OCT 15 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 0900 UTC. ...SPECIAL FEATURE... AT 0600 UTC A BROAD AREA OF LOW PRESSURE WAS ESTIMATED NEAR 09N94.5W AT 1008 MB. SATELLITE IMAGERY OVER THE PAST 12 TO 24 HOURS HAS SHOWN A DEFINITIVE MID LEVEL CLOUD SWIRL MOVING NW...AND ANCHORED IN THE ITCZ...AND ALONG THE E END OF AN ELONGATED LOW LEVEL CYCLONIC GYRE. CONVECTION NEAR THIS CENTER WAS MINIMAL YESTERDAY AFTERNOON AND EARLY TONIGHT...BUT REMAINED SCATTERED JUST TO THE N. IN RECENT HOURS SCATTERED MODERATE TO STRONG CONVECTION HAS BEGUN TO CONCENTRATE TO THE NE OF THE CENTER WITH ISOLATED MODERATE CONVECTION NOW NEAR THE CENTER. THIS LIMITED CONVECTION NEAR THE CENTER IS NOW ALLOWING FOR A DVORAK CLASSIFICATION AT THIS TIME. HOWEVER...THE SOMEWHAT VIGOROUS MID LEVEL TURNING PERSISTING IN SATELLITE IMAGERY...AND THE FACT THAT ALL FOUR GLOBAL MODELS DEVELOP A SIGNIFICANT LOW OUT OF THIS SYSTEM IN THE NEXT SEVERAL DAYS SUGGEST THAT THERE IS A MODERATE CHANCE FOR A POSSIBLE TROPICAL CYCLONE WITHIN THE NEXT 48 HOURS. GIVEN THE LOW SHEAR... ABUNDANT MOISTURE...AND WARMER THAN NORMAL SSTS IN THE AREA...IT IS NOT SURPRISING THAT THE MODELS ARE CALLING FOR GENESIS. SURPRISINGLY...AN OVERNIGHT QUIKSCAT PASS DI NOT SHOW A PRONOUNCED SURFACE CIRCULATION WITH THIS ESTIMATED CENTER...BUT A BROAD AND WELL DEFINED CYCLONIC CIRCULATION WELL TO THE W...IN THE VICINITY OF THE TROPICAL WAVE ALONG 107W. AT 0600 UTC THE 1011 MB REMNANT LOW OF PATRICIA WAS LOCATED NEAR 22N112.5W...MOVING WSW AND GRADUALLY AWAY FROM THE SOUTHERN TIP OF BAJA CALIFORNIA. NO CONVECTION REMAINS NEAR THE CENTER OF THIS LOW CLOUD SWIRL...AND STRONG UPPER CONVERGENCE ACROSS THIS SYSTEM IS PRODUCING A VERY STABLE MID TO UPPER ENVIRONMENT. THE REMNANTS OF PATRICIA ARE EXPECTED TO GRADUALLY WEAKEN AND FOLLOW A WSW TO W TRACK FOR THE NEXT FEW DAYS...DISSIPATING TO AN OPEN TROUGH WITHIN 48 HOURS. ...TROPICAL WAVES... A TROPICAL WAVE WAS ANALYZED ALONG 107W...MOVING W AT 10-15 KT. THIS WAVE IS ON THE WESTERN EDGE OF AN AREA OF BROAD CYCLONIC TURNING THAT EXTENDS E TO 88W. AS MENTIONED ABOVE...A RECENT QUIKSCAT PASS SHOWED THAT THIS WAVE HAS HELPED TO SPAWN A BROAD LOW WITHIN THE W END OF THIS GYRE. CONVERGENCE TO THE W OF THIS GYRE WAS PRODUCING SCATTERED CONVECTION DESCRIBED BELOW IN THE ITCZ SECTION. GLOBAL MODELS SUGGEST THAT SOME OF THE MOISTURE ENTRAINED IN THIS CIRCULATION WILL BECOME ABSORBED INTO THE DEVELOPING LOW TO THE E OVER THE NEXT SEVERAL DAYS. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE WAS ALONG 10N76W TO 09N93W TO 08N96W TO 12N106W TO 10N117W TO 12N128W TO 14N140W. ISOLATED TO SCATTERED MODERATE TO STRONG CONVECTION WAS OCCURRING FROM 05N TO 14N BETWEEN 109W AND 121W...PARTLY IN ASSOCIATION WITH A TROPICAL WAVE ALONG 107W. AN ELONGATED TROUGH AND COMPLEX LOW INTERSECTS THE ITCZ BETWEEN 126W AND 130W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION WAS OCCURRING TO THE W OF THIS FEATURE...AND WITHIN 300 NM EITHER SIDE OF THE ITCZ TO 134W. ...DISCUSSION... 1019 MB HIGH PRES CURRENTLY NEAR 28N128W WILL MIGRATE N TO NW OVER THE NEXT TWO DAYS AS THE NEGATIVELY TILTED DEEP LAYER TROUGH OVER THE EASTERN PACIFIC N OF THE FORECAST AREA PASSES INTO THE WESTERN U.S. THIS WILL MAKE WAY FOR DEEP LAYER RIDGING TO BUILD ACROSS THE N WATERS. STEERING FLOW FOR THE REMNANTS OF PATRICIA WILL BE DOMINATED BY THIS RIDGE TO ITS NW THE REMAINDER OF THE PERIOD. THE TIGHT PRES GRADIENT ALONG THE COAST OF CALIFORNIA S TO THE BAJA PENINSULA BETWEEN THIS RIDGE AND INDUCED LOW LEVEL TROUGHING FROM PATRICIA IS GENERATING 20-25 KT N TO NW WINDS ALONG THE WESTERN BAJA COAST N OF PATRICIAS REMNANTS THAT WILL CONTINUE FOR ABOUT ONE MORE DAY BEFORE SHIFTING NW AND DIMINISHING. THE WESTWARD BUILDING SURFACE RIDGE HAS ALLOWED EASTERLY FLOW TO INCREASE W OF 122W BETWEEN THE RIDGE AXIS AND A COMPLEX LOW/TROUGH EMBEDDED IN THE ITCZ JUST E OF 130W. AN OVERNIGHT QUIKSCAT PASS SHOWED AN ELONGATED TROUGH ALIGNED NW TO SE IN THE AREA BETWEEN 130W AND 124W...WITH TWO EMBEDDED CYCLONIC CENTERS. FRESH WLY FLOW ON THE S SIDE OF THE LOW AND S OF THE ITCZ AXIS IN PRODUCING EXCELLENT LOW LEVEL CONVERGENCE AND A BROAD AREA OF SCATTERED MODERATE CONVECTION. THIS RIDGE WILL ALSO PREVENT THE NEXT COLD FRONT...EXPECTED TO APPROACH THE FORECAST AREA THU...FROM MOVING INTO NW WATERS. THE AFOREMENTIONED DEEP LAYER TROUGHING WELL NORTH OF THE AREA IS PRODUCING NW SWELL THAT IS MOVING SOUTHEASTWARD THROUGH NORTHERN FORECAST WATERS. A STRONG COLD FRONT IS PROJECTED TO MOVE ACROSS THE GULF OF MEXICO AND INDUCE A TEHUANTEPEC GAP WIND EVENT. THIS IS LIKELY TO COMMENCE IN ABOUT THREE DAYS. GIVEN THE WARMER THAN NORMAL WATERS SOUTH OF MEXICO FOR THIS TIME OF YEAR...THIS MAY CAUSE STRONGER WINDS IN THE EVENT THEN PERHAPS OTHERWISE ANTICIPATED. IT IS...HOWEVER...TOO EARLY TO STATE WHETHER THIS GAP EVENT WILL REACH GALE FORCE. $$ STRIPLING/LANDSEA