000 AXPZ20 KNHC 270307 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN SEP 27 2009 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0315 UTC. ...ITCZ... AXIS IS CENTERED ALONG 8N79W TO 9N90W TO 12N98W TO 11N107W TO 13N120W TO 12N140W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 83W-87W AND 88W-91W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM N OF THE AXIS W OF 137W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 95W-98W AND 102W-105W. ...DISCUSSION... AN ELONGATED MID/UPPER LEVEL TROUGH EXTENDS SW INTO THE AREA ACROSS NRN BAJA CALIFORNIA AND EXTREME SRN CALIFORNIA SW TO A PAIR OF MID/UPPER LEVEL LOWS ROTATING CYCLONICALLY AROUND A CENTER POINT NEAR 30N135W. THE BROAD BASE OF THIS TROUGH COVERS THE AREA FROM 19N-25N BETWEEN 120W AND 142W...WITH MID TO UPPER CONVERGENCE AND STRONG SUBSIDENCE NOTED ACROSS MOST OF THE SRN HALF OF THE BROAD TROUGH. A JET STREAM BRANCH ROUNDS THE BASE OF THE TROUGH FROM 20N140W NE TO 23N120W...THEN WEAKENS AS IT CONTINUES NE TO ACROSS NRN BAJA CALIFORNIA AND TO ACROSS NRN MEXICO. MAXIMUM WIND SPEEDS WITH THE JET WERE ESTIMATED IN THE RANGE OF 50-65 KT. A NEARLY STATIONARY 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 REMNANT LOW OF NORA LOCATED NEAR 17N126W WITH A PRES OF 1012 MB. DIFFLUENT FLOW AND SPEED DIVERGENCE ALOFT UNDERNEATH AND ALONG THE S SIDE OF THE RIDGE CONTINUES TO VENTILATE AND SUSTAIN CONVECTION ALONG THE ITCZ. BROAD LOW TO MID LEVEL TROUGHING EXTENDS N FROM THE ITCZ BETWEEN 92W-100W N TO ACROSS MEXICO AND INTO 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 SHOWERS AND TSTMS FROM N OF THE ITCZ TO THE MEXICAN COASTLINE BETWEEN 92W AND 108W. DEEP LAYERED EASTERLIES WERE DEPICTED BY SCATTEROMETER DATA FROM THIS MORNING...AND WERE ALSO INDICATED IN SATELLITE DERIVED WINDS FROM THE MEXICAN COAST S FOR ABOUT 5 DEG... 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 THIS PORTION OF THE AREA. AT THE SURFACE...A RIDGE EXTENDS SE INTO THE AREA THROUGH 32N138W TO 25N118W. HIGH PRES COVERS THE AREA N OF 21N AND W OF ABOUT 119W. THE REMNANT LOW OF FORMER TROPICAL DEPRESSION NORA MENTIONED EARLIER TO NEAR 17N126W IS MOVING W ABOUT 7 KT. SCATTERED STRONG CONVECTION IS WITHIN 120 NM OF THE CENTER IN THE NW QUADRANT WITH 20-25 KT WINDS WITHIN 120 NM IN THE N SEMICIRCLE. STRONG SWLY SHEAR WILL CONTINUE TO INHIBIT ANY REINTENSIFICATION OF THIS LOW...AND IT SHOULD DISSIPATE WITHIN THE NEXT 18-24 HOURS NEAR 130W. THE PRES GRADIENT BETWEEN THE RIDGE...THE REMNANT LOW OF NORA...AND THE EQUATORIAL TROUGH CONTINUED TO PRODUCE A BROAD ZONE OF 20-25 KT NE WINDS OF 20 KT FROM 13N-20N W O 134W WITH SEAS IN THE 8-10 FT RANGE. THESE WINDS ARE FORECAST TO LET UP TO NE-E TO 20 KT WITH SEAS SUBSIDING TO 8 FT IN 48 HOURS AS THE RIDGE WEAKENS SOME. A 1006 MB SURFACE LOW IS NEAR 12N116W MOVING W ABOUT 10 KT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM IN THE NW QUADRANT OF THE LOW. SOME SLOW DEVELOPMENT OF THIS SYSTEM IS EXPECTED OVER THE NEXT COUPLE OF DAYS. A WEAK TROUGH MOVING W 10 KT IS ALONG 96W FROM 10N TO 15N. THIS TROUGH IS PART OF A BROAD AREA OF DISORGANIZED SCATTERED SHOWER AND TSTM ACTIVITY FROM THE ITCZ NWD TO THE MEXICAN COAST AND BETWEEN 92W-105W BEING ENHANCED TO SOME EXTENT BY THE LOW TO MID LEVEL TROUGH DESCRIBED ABOVE. WITHIN THIS GYRE OF LOW PRES...A LOW IS FORECAST TO POSSIBLY FORM NEAR 13N104W IN ABOUT 24 HOURS. THIS ENTIRE AREA PRESENTLY HAS A LOW POTENTIAL FOR TROPICAL CYCLONE DEVELOPMENT OVER THE NEXT 48 HOURS AS IT TRANSLATES WWD. A STRONG COLD FRONT WILL PASS TO THE N OF THE REGION THROUGH MON. A LARGE NW SWELL TRAIN CONSISTING OF 8-10 FT SEAS PER LATEST WAVEWATCH MODEL GUIDANCE SHOULD TO STAY TO THE N OF 32N FOR THE MOST PART...BUT CANNOT RULE OUT A FEW 9 FT SEAS FROM SPREADING INTO THE FAR NRN WATERS...N OF ABOUT 28N. $$ AGUIRRE