000 AXPZ20 KNHC 291607 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC TUE SEP 29 2009 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1530 UTC. ...SPECIAL FEATURES... UNDERNEATH AND TO THE S OF A LARGE UPPER LEVEL HIGH ALONG THE W COAST OF MEXICO HAS EVOLVED A LARGE AND BROAD CYCLONIC CIRCULATION IN THE LOW TO MID LEVELS...PORTIONS OF WHICH HAVE BEEN TRACKED FOR DAYS MOVING ACROSS THE FAR W CARIB...CENTRAL AMERICA...AND THEN S CENTRAL MEXICO AND THE ADJACENT PACIFIC. SATELLITE IMAGERY THIS MORNING REVEALS THE MID LEVEL REMNANT OF A LARGE CONVECTIVE CLUSTER THAT WAS ALONG THE W COAST OF MEXICO 24 HOURS AGO...IN THE FORM OF A DYING MID LEVEL VORT CENTER...WAS LOCATED WITHIN THE NRN END OF THIS ELONGATED AND BROAD CIRCULATION...NEAR 19N112W. THE LARGE BROADER CIRCULATION ENVELOPE WAS SUGGESTED BY MORNING SATELLITE IMAGERY FROM NEAR 21N111W TO NEAR 11N106W. A 1007 MB SURFACE LOW WAS ANALYZED NEAR 17N108W AT 12Z...WHILE ANOTHER LOW LEVEL LOW MAY ALSO BE ATTEMPTING TO FORM FATHER S NEAR 14N107W. THE BROAD CIRCULATION HAS ENTRAINED ABUNDANT TROPICAL MOISTURE AND IS FORECAST BY GLOBAL MODELS TO SHIFT NW OVER THE NEXT FEW DAYS AND GAIN BETTER ORGANIZATION. THERE IS A MODERATE CHANCE FOR TROPICAL CYCLONE DEVELOPMENT WITHIN THIS SYSTEM. A BROAD AREA OF 20-25 KT WINDS CONTINUES TO BE INDICATED BY A PARTIAL MORNING QUIKSCAT PASSAGE ACROSS THE NE SEMICIRCLE OF THIS CIRCULATION...WHERE SEAS ARE LIKELY NEAR 10 FT. ...TROPICAL WAVE... A TROPICAL WAVE WAS ANALYZED ALONG 90W MOVING W 10-15 KT. NO SIGNIFICANT CONVECTION ASSOCIATED WITH THE WAVE. CYCLONIC TURNING TO THE W OF THIS AREA ALONG 96/97W MAY IN FACT BE THE LOCATION OF THIS WAVE...BUT PLACEMENT IS UNCERTAIN. ...ITCZ... AXIS WAS ALONG 09N84W TO 13N103W THEN CONTINUING FROM 16N114W TO 12N125W TO 12N140W. SCATTERED MODERATE TO ISOLATED STRONG IS WITHIN 200 NM EITHER SIDE OF AXIS FROM 92W TO 102W...AND FROM 11N TO 16N BETWEEN 122W TO 128W. SIMILAR CONVECTION IS 11N TO 13N W OF 133W. ...DISCUSSION... A SW-NE ALIGNED UPPER LEVEL CYCLONIC CIRCULATION HAS BECOME CONSIDERABLY ELONGATED DURING THE PAST 24 HOURS...CENTERED NEAR 27N133W...AND WAS EMBEDDED WITHIN A L/W TROUGH EXTENDING FROM THE PACIFIC NW OF N AMERICA SW TO THIS ELONGATED CYCLONE...THEN W AND NW IN A TUTT LIKE FASHION BEYOND 30N152W. S OF THE ELONGATED CYCLONE A BROAD TROUGH WAS STILL CARVED OUT INTO THE NRN FRINGES OF THE TROPICS...EXTENDING N OF 16N BETWEEN 127W AND 152W. A 55-65 KT JET AXIS WAS DIVING INTO THE BACK SIDE OF THE TROUGH AXIS ALONG 20N AND TO THE NE OF THE HAWAIIAN ISLANDS AND INTO THE BASE OF THE TROUGH...WHILE A BROADER 60-75 KT JET ON THE E SIDE OF THIS AXIS WAS LIFTING OUT AND INTO CALIFORNIA AND THE WRN U.S. THIS UPPER TROUGH HAS COME INTO PHASE AND IS BEING REINFORCED BY A LARGE UPPER TROUGH TO THE N AND WILL MAINTAIN A SSW-NNE ELONGATION OVER THE NEXT FEW DAYS. DOWNSTREAM...AN AMPLIFYING UPPER LEVEL RIDGE IS LOCATED SE OF THE CYCLONIC CIRCULATION...AND EXTENDED FROM A LARGE ANTICYCLONE OVER WRN MEXICO NEAR 21N106W EASTWARD INTO THE GULF OF MEXICO... AND SW THROUGH 20N118W TO A COL NEAR 13N135W. ANOTHER UPPER ANTICYCLONE WAS CENTERED OVER THE S CENTRAL PACIFIC NEAR 12N152W. GENERALLY DRY AND SUBSIDENT CONDITIONS COULD BE FOUND ACROSS THE BASE OF THE UPPER TROUGH...AND ACROSS THE NW AND NRN FLANKS OF THE RIDGE...JUST SE OF THE SUBTROPICAL JET. A MID TO UPPER LEVEL CYCLONIC CIRCULATION WAS NOTED NEAR 14N99W AND EXTENDED S AS A TROUGH INTO THE ITCZ...MOVING W AT 15 KT ACROSS ALONG THE COASTAL WATERS OF SRN MEXICO AND THE ADJACENT TROPICAL EPAC. THIS SYSTEM WAS PRODUCING SCATTERED MODERATE TO STRONG CONVECTION ACROSS THE EPAC. AN AREA OF BROAD AND MODEST LOW TO MID LEVEL CYCLONIC TURNING WAS NOTED JUST TO THE SE OF THIS FEATURE...AND COULD IN FACT BE THE TROPICAL WAVE ANALYZED A BIT FURTHER TO THE E. THIS ILLUSTRATES THE DIFFICULTY IN WAVE TRACKING ACROSS THE EPAC. AT THE SURFACE...A HIGH PRES RIDGE EXTENDED FROM A 1039 MB HIGH LOW NEAR 42N152W SE TO OFFSHORE OF BAJA CALIFORNIA NEAR 24N116W. THE ITCZ CONTINUED TO BE QUITE ACTIVE ACROSS SEVERAL ZONES IN THE AREA...UNDER GOOD DIFFLUENCE ALOFT. SEVERAL WAVES...LOWS AND PERTURBATIONS WERE EVIDENT IN SHORT WAVE INFRARED SATELLITE IMAGERY OVERNIGHT. FIRST THE BROAD LOW AND CONVECTION OFF OF MEXICO...ANOTHER LARGE CYCLONIC CIRCULATION CENTERED NEAR 13N121W...AND THE REMNANTS OF NORA...A BENIGN 1011 MB LOW NEAR 15N133W. REGIONAL SEAS ARE BEING DOMINATED BY MODERATE PERIOD SRN HEMISPHERE SE SWELL...AND LONGER PERIOD NW AND SSW SWELL. THE FRESH TO STRONG E TO SE FLOW ALONG THE MEXICAN COAST WAS GENERATING SEAS OF 7 TO 10 FT IN THIS CONFUSED MIX. SEAS IN EXCESS OF 8 FT WILL GRADUALLY PROPAGATE NWD ACROSS THE EQUATOR TO 12N BY MID WEEK AS SEVERAL NEW PULSES OF LARGE SE AND SW SWELL MOVE INTO THE AREA. $$ STRIPLING