000 AXPZ20 KNHC 050350 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC FRI OCT 05 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0330 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS W ACROSS THE SOUTHERN CARIBBEAN ALONG 10N FROM THE COLOMBIAN COAST TO ACROSS NORTHERN COSTA RICA TO 09N84W...THEN DIPS SW TO 06N98W. THE MONSOON TROUGH RESUMES FROM 14N107W THROUGH AN EMBEDDED LOW PRES AT 13N112W...CONTINUING SW TO 09N120W...THEN W TO 10N128W...THEN SW TO 07N138W WHERE LOW LEVEL WINDS INDICATE A TRANSITION TO AN ITCZ WHICH CONTINUES SW TO BEYOND 06N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 30 NM OF COAST OF CENTRAL AMERICA FROM 84W TO 86W AND FROM 87W TO 93W...WITHIN 180 NM OF 07N82W AND 10N95W... AND WITHIN 120 NM EITHER SIDE OF A LINE FROM 13N101W TO 14N110W TO 12N115W...WITHIN 90 NM EITHER SIDE OF A LINE FROM 07N110W TO 08N117W...AND WITHIN 180 NM OF 10N126W AND 09N133W. ...DISCUSSION... A BROAD UPPER LEVEL CYCLONE IS STATIONARY N OF THE DISCUSSION AREA NEAR 35.5N135W TRAILING AN UPPER TROUGH OVER THE NW PORTION PRECEDED BY SOUTHWESTERLY 50-60 KT JET ROUGHLY WITHIN 150 NM EITHER SIDE OF LINE 27N140W TO 33N130W. A SMALL UPPER CYCLONE HAS STALLED NEAR 19N130W WITH A TROUGH S TO A THIRD CYCLONE AT 09N134W. AN UPPER LEVEL ANTICYCLONE IS POSITIONED NEAR 27N115W WITH AN UPPER RIDGE EXTENDING N BEYOND 32N115W WITH A WESTERLY 50-90 KT JET INDICATED ALONG THE RIDGE CREST OVER SOUTHERN CALIFORNIA AND THE NORTHERN BAJA PENINSULA WITH THE JET DISSIPATING OVER WESTERN ARIZONA. THIS JET IS ACCOMPANIED BY A THINNING MOSITURE BAND. THE ENVELOPE OF ANTICYCLONIC FLOW DOMINATES THE UPPER LEVELS FROM 10N-32N BETWEEN 105W AND 127W. WEAK UPPER DIFFLUENCE ALONG THE SOUTHERN PERIPHERY OF THIS LARGE RIDGE IS SUPPORTING THE CONVECTION ALONG THE MONSOON TROUGH AS PREVIOUSLY DESCRIBED. THE DEBRIS MOISTURE FANS OUT BOTH N CONVECTIVE CLUSTERS BUT APPEARS TO EVAPORATE BEFORE REACHING ALONG 16N. AN UPPER TROUGH EXTENDS S ACROSS THE WESTERN GULF OF MEXICO AND OVER CENTRAL MEXICO TO A BASE AT 16N102W. A SECOND UPPER TROUGH EXTENDS SW ACROSS THE WESTERN CARIBBEAN TO ACROSS NORTHERN COSTA RICA. A BROAD UPPER RIDGE DOMINATES THE UPPER LEVELS OF THE DEEP TROPICS TO THE E OF 105W...BUT THERE ARE EMBEDDED SMALL UPPER CYCLONES OBSERVED WITHIN THE BROAD RIDGE. DENSE UPPER MOISTURE IS NOTED FROM 05N TO 10N E OF 96W. SOME OF THE DEBRIS MOISTURE FROM THE CONVECTION ALONG 14N BETWEEN 100W AND 113W CONTINUES TO STREAM NE ACROSS SE MEXICO AND THE EASTERN GULF OF MEXICO. ELSEWHERE AT THE LOW LEVELS...BROAD SURFACE RIDGING COVERS MUCH OF THE DISCUSSION AREA N OF 20N W OF 110W. SOUTHWESTERLY LOW LEVEL WINDS AT 15 TO 20 KT ALONG WITH CROSS EQUATORIAL S SWELL CONTINUES TO RESULT IN AN AREA OF SEAS TO 8 FT IN THE AREA BOUNDED BY 03N TO 08N BETWEEN 110W AND 116W. THIS AREA WILL SHIFT SLIGHTLY N ON FRI...THEN WINDS WILL DIMINISH TO 15 KT AND SEAS WILL SUBSIDE TO LESS THAN 8 FT. IN THE MEANTIME...NW WINDS NE OF THE SURFACE RIDGE WILL INCREASE TO 20 TO 25 KT JUST TO THE W OF THE NORTHERN BAJA CALIFORNIA PENINSULA. THE INITIAL NORTHERLY SURGE THAT PASSED TROUGH THE TEHUANTEPEC AREA IS STILL PROPAGATING W AND IS CURRENTLY IN THE AREA FROM 13N TO 16N BETWEEN 104W AND 112W...AND WILL MERGE WITH THE INCREASING WINDS OVER THE N SEMICIRCLE OF A SURFACE LOW DEVELOPING AT 13N112W. THE LOW WILL MOVE W TO NEAR 12N122W ON SAT WITH THE GRADIENT BEGINNING TO RELAX BY THEN. GAP WINDS...NORTHERLY WINDS AT 20 TO 25 KT ARE EXPECTED TO PULSE ACROSS THE GULF OF TEHUANTEPEC THROUGH FRI NIGHT...THEN DIMINISH ON SAT. NE TO E WINDS AT 20 TO 25 KT IN AND DOWNSTREAM OF THE GULF OF PAPAGAYO WILL DIMINISH LATE TONIGHT. $$ NELSON