000 AXPZ20 KNHC 262144 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SAT SEP 26 2009 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2115 UTC. ...ITCZ... AXIS WAS ALONG 08N79W TO 11N90W TO 12N104W TO 10N115W TO 15N126W TO 12N132W TO 12N140W. SCATTERED MODERATE TO STRONG WITHIN 120 NM OF THE AXIS W OF 135W. SCATTERED MODERATE ISOLATED STRONG FROM 09N TO 14N BETWEEN 92W AND 96W AND FROM 09N TO 14N BETWEEN 100W AND 105W. ...DISCUSSION... AN ELONGATED MID/UPPER LEVEL TROUGH EXTENDS SW INTO THE AREA ACROSS NRN BAJA CALIFORNIA/EXTREME S CALIFORNIA...TO A PAIR OF MID/UPPER LEVEL LOWS ROTATING CYCLONICALLY ABOUT A CENTER POINT NEAR 30N135W. THE BROAD BASE OF THIS TROUGH COVERED THE AREA FROM 19N-25N BETWEEN 120W AND 142W...WITH MID TO UPPER CONVERGENCE AND STRONG SUBSIDENCE NOTED ACROSS MOST OF THE S HALF OF THE BROAD TROUGH. A JET SEGMENT ALOFT ALONG THE SRN FLANKS OF THIS TROUGH EXTENDED FROM 19N141W TO 23N120W...THEN WEAKENED AND LIFTED NE TO ACROSS CENTRAL BAJA CALIFORNIA AND CONTINUES NEWD TO ACROSS NORTHERN MEXICO. MAXIMUM WIND SPEEDS WITH THE JET WERE ESTIMATED AT 50-65 KT. A QUASISTATIONARY MID/UPPER RIDGE PERSISTED S OF THIS UPPER TROUGH PATTERN... EXTENDING FROM THE ERN GULF OF MEXICO WSW ACROSS CENTRAL MEXICO THEN SW ACROSS THE REMNANTS OF NORA THROUGH A SERIES OF SMALL AND WEAK UPPER LEVEL ANTICYCLONES TO ANOTHER UPPER HIGH NEAR 12N150W LOCATED S OF THE HAWAIIAN ISLANDS. DIFFLUENT FLOW AND SPEED DIVERGENCE ALOFT UNDERNEATH AND ALONG THE S SIDE OF THE RIDGE CONTINUES TO VENTILATE AND SUSTAIN CONVECTION ALONG THE ITCZ FROM PANAMA AND THE EXTREME SW CARIB WWD BEYOND 140W. THE REMNANTS OF NORA...NEAR 17N126.5W 1008 MB MOVING WNW 7 KT...CONTINUED TO FLARE WITH ISOLATED MODERATE CONVECTION ACROSS THE S AND SE QUADRANTS...WITH 20-25 KT WINDS STILL OCCURRING ACROSS THE NRN SEMICIRCLE. HOWEVER STRONG UPPER SHEAR WILL CONTINUE TO INHIBIT ANY REINTENSIFICATION OF THIS LOW. A SURFACE RIDGE EXTENDED SE INTO THE AREA THROUGH 32N136W TO 26N122W. HIGH PRES COVERS THE AREA N OF 21N AND W OF ABOUT 125W. THE PRESSURE GRADIENT BETWEEN THE HIGH...THE REMNANTS OF NORA...AND THE EQUATORIAL TROUGH CONTINUED TO PRODUCE A BROAD ZONE OF 20-25 KT NELY WINDS TO THE N AND NW OF THE REMNANTS OF NORA...FROM BEYOND 30N TO 20N AND W OF 125/126W...WHERE SEAS WERE 7-9 FT IN NELY WIND WAVES AND NW SWELL. A 1006 MB SURFACE LOW HAS DEVELOPED DURING THE PAST 12 HOURS WITHIN THE ITCZ NEAR 12N115W...WITH A BROAD AREA OF MODERATE CONVECTION SURROUNDING IT. SLOW AND GRADUAL IMPROVEMENT IN THE ORGANIZATION OF THIS LOW IS EXPECTED TO OCCUR OVER THE NEXT FEW DAYS. OVER EASTERN PORTIONS OF THE AREA...A BROAD LOW/MID LEVEL TROUGH WAS ALONG 96/97W...FROM THE EPAC ITCZ N AND INTO MEXICO AND THE EXTREME SW GULF OF MEXICO. THIS FEATURE IS LIKELY A SOUTHERN PORTION OF A FRACTURED TROPICAL WAVE THAT INTERACTED WITH A TUTT LOW REFLECTION ACROSS THE CENTRAL AND WRN CARIBBEAN A FEW DAYS AGO. THERE IS A BROAD AND VERY MOIST CYCLONIC CIRCULATION ASSOCIATED WITH THIS FEATURE...MOVING W NEAR 10 KT...WITH SCATTERED TO NUMEROUS CONVECTION FROM N OF THE ITCZ TO THE MEXICAN COASTLINE BETWEEN 92W AND 107W. DEEP LAYERED EASTERLIES WERE DEPICTED BY RECENT SCATTEROMETER PASSES AND SATELLITE DERIVED WINDS FROM THE MEXICAN COAST S FOR ABOUT 5 DEGREES...INCLUDING THE GULF OF TEHUANTEPEC...WITH LARGE POCKETS OF 20-25 KT WINDS...AND VERY GUSTY IN CONVECTION. THIS IS CREATING STEEP SEAS AND VERY ROUGH MARINE CONDITIONS ACROSS THE AREA. A STRONG COLD FRONT BYPASSING THE REGION TO THE N DURING THE WEEKEND WILL BE FOLLOWED BY A LARGE NW SWELL TRAIN CONSISTING OF 8-10 FT SEAS PER LATEST WAVEWATCH MODEL GUIDANCE. EXPECT THESE SEAS TO BEGIN AFFECTING THE FAR NRN PORTION OF THE AREA ON SUN WITH PEAK WAVE HEIGHTS REMAINING N OF THE AREA....N OF 35N. $$ STRIPLING