000 AXPZ20 KNHC 101005 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC WED OCT 10 2012 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS W ACROSS NORTHERN COSTA RICA TO THE PACIFIC COAST AT 10N86W AND CONTINUES TO 12N97W TO 11N107W TO 12N120W WHERE IT LOSES IDENTITY IN SE-S FLOW TO THE SW OF THE REMNANT LOW OF WHAT WAS TROPICAL STORM OLIVIA. THE MONSOON TROUGH RESUMES SW OF THE LOW AT 11N126W TO 09N131W WHERE LOW LEVEL WINDS INDICATE IT TRANSITIONS TO THE ITCZ WHICH CONTINUES W TO BEYOND 06N140W. NUMEROUS STRONG CONVECTION IS ALONG AND WITHIN 120 NM N OF THE MONSOON TROUGH BETWEEN 87W-93W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM N OF THE MONSOON TROUGH BETWEEN 93W-105W...WITHIN 180 NM S OF THE MONSOON TROUGH BETWEEN 87W-90W...AND ALSO WITHIN 90 NM N THE ITCZ AXIS. ...DISCUSSION... A LARGE UPPER LEVEL LOW N OF THE DISCUSSION AREA AT 35N124W HAS BEGUN TO MOVE SSE WITH AN ASSOCIATED UPPER TROUGH EXTENDING SW FROM IT THROUGH 32N124W AND SW TO 25N128W AND TO 23N136W WHERE IT BECOMES A SHEAR AXIS TO W OF THE AREA AT 21N AND CONTINUES SW TO AN ELONGATED UPPER LEVEL LOW AT 17N147W. A SHORTWAVE TROUGH IS ROTATING THROUGH THE SRN PERIPHERY OF THE INITIAL TROUGH FROM 32N127W TO 26N134W. A SURFACE TROUGH REFLECTION EXTENDS FROM JUST OFFSHORE CENTRAL CALIFORNIA SW TO NEAR 31N28W. THE UPPER LEVEL LOW IS FORECAST TO TURN MORE TO THE SE TODAY AND THEN MOVE E TO INLAND SRN CALIFORNIA ON THU WITH A TRAILING TROUGH SW TO NEAR 22N131W BY FRI AT WHICH TIME NRN STREAM ENERGY IN THE FORM OF ANOTHER UPPER LOW DIVES SEWD SHARPENING THE TRAILING TROUGH LATE ON FRI. THIS WILL PUSH A COLD FRONT SE ACROSS THE NRN WATERS...BUT IT EXPECTED THAT FRONT WILL BE RATHER WEAK AS THE UPPER LOW WEAKENS. AN UPPER LEVEL ANTICYCLONE IS IDENTIFIED TO BE AT 18N105W WITH AN UPPER RIDGE EXTENDING WSW TO A CREST AT 11N135W. UPPER DEBRIS MOSITURE TIED TO SCATTERED MODERATE/ISOLATED STRONG CONVECTION WITHIN 30 NM OF 16N118.5W...AND WITH CONVECTION ALONG AND NEAR THE MONSOON TROUGH IS BEING ADVECTED NNE TOWARDS SOUTHERN BAJA CALIFORNIA AS IT GETS CAUGHT UP IN A NE TO SW JET STREAM BRANCH SITUATED BETWEEN THE ANTICYCLONE AND THE BROAD TROUGH OVER THE NRN PORTION OF THE AREA AS MENTIONED ABOVE. CLOUD MOTION VECTORS INDICATE A POCKET OF 50-65 KT WINDS WITH THE JET STREAM BRANCH FROM 23N-25N BETWEEN 113W-119W. AN UPPER ANTICYCLONE E OF THE PACIFIC BASIN OVER THE GULF OF HONDURAS HAS ITS ANTICYCLONIC ENVELOPE EXTENDING S OVER THE DISCUSSION AREA TO THE N OF ABOUT 10N AND E OF 102W. THE ASSOCIATED UPPER DIFFLUENCE IS SUPPORTING THE CONVECTION ALONG THE EASTERN SEGMENT OF THE MONSOON TROUGH AS PREVIOUSLY DESCRIBED. DENSE DEBRIS MOISTURE IS OBSERVED WITHIN THIS UPPER RIDGE TURNING N ALONG THE RIDGE PERIPHERY AT 102W...THEN NEWD TO OVER MUCH OF SRN MEXICO WHERE IT MERGES INTO A DENSE TROPICAL PLUME THAT CONTINUES NE TO WELL E OF THE AREA TO ACROSS THE EASTERN GULF OF MEXICO. ELSEWHERE AT THE LOW LEVELS...SURFACE HIGH PRESSURE OF 1022 MB IS ANALYZED NEAR 28N140W WITH BROAD RIDGING COVERING THE AREA N OF 18N AND W OF 116W. THE REMNANT LOW OF FORMER TROPICAL STORM OLIVIA IS NOW LOCATED NEAR 14N124W MOVING SW AROUND 10 KT. THE LOW IS VOID OF ANY DEEP CONVECTION...AND IS MARKED BY A SWIRL OF BROKEN LOW AND MID LEVEL CLOUDS WITH ISOLATED SHOWERS WITHIN 60 NM OF THE LOW IN THE NW SEMICIRCLE AND 30 NM IN THE SE SEMICIRCLE. THE LOW IS FORECAST TO REACH NEAR 12N129W IN ABOUT 24 HRS...THEN WEAKEN FURTHER INTO A TROUGH FROM 16N128W TO 11N134W BY THU NIGHT. THE ASCAT PASS FROM 0648 UTC THIS MORNING SHOWED A SWATH OF NE 20-25 KT WINDS WITHIN 270 NM OF THE LOW IN THE NW QUADRANT. THIS WINDS WILL CONTINUE THROUGH TONIGHT...THEN DIMINISH TO 20 KT W OF THE TROUGH BY THU NIGHT. GAP WINDS...NORTHERLY WINDS WILL PULSE AT 20-25 KT THROUGH AND DOWNSTREAM THE GULF OF TEHUANTEPEC REACHING NEAR 15N96W BEGINNING TONIGHT. MODEL WIND AND STABILITY GUIDANCE INDICATES THAT THESE WINDS WILL SPREAD MORE TO THE SW BY THU NIGHT AS POSSIBLE LOW PRES FORMS JUST TO THE S OF THE GULF. GLOBAL MODELS ARE IN CONSENSUS IN FORECASTING THE AFOREMENTIONED LOW PRES TO FORM JUST S OF THE GULF OF TEHUANTEPEC AS THE NORTHERLY DRAINAGE FLOW THROUGH THE GULF OF TEHUANTEPEC ENHANCES THE FLOW AROUND THE N SEMICIRCLE OF THE LOW. ANOTHER LOW IS FORECAST TO FORM NEAR 100W IN 24 HRS. WAVEWATCH MODEL GUIDANCE HAS BEEN CONSISTENT IN FORECASTING A LARGE NW SWELL WAVE TRAIN THAT ENCROACHES INTO THE FAR NW SECTION OF THE AREA BEGINNING ON WED AND LASTING THROUGH AT LEAST THE END OF THE WEEK. THIS IS RELATED TO THE COLD FRONTAL SYSTEM THAT IS FORECAST TO PASS JUST TO THE N OF THE AREA BY THAT TIME. THE SWELLS ARE FORECAST TO PRODUCE SEAS OF UP TO 10 OR 11 FT. $$ AGUIRRE