000 AXPZ20 KNHC 162140 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC WED NOV 16 2011 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ALONG 10N86W TO 1008 MB LOW PRES NEAR 09N91.5W TO 07N100W TO 09N110W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 09N110W TO 11N116W THEN RESUMES FROM 11N122W TO 08N133W THEN RESUMES FROM 08N136W TO 08N140W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM EITHER SIDE OF THE MONSOON TROUGH BETWEEN 90W AND 97W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 08N TO 12N BETWEEN 115W AND 123W...AND FROM 07N TO 10N BETWEEN 132W AND 137W. ALSO...SCATTERED MODERATE CONVECTION IS IN THE GULF OF PANAMA N OF 05N E OF 82W. ...DISCUSSION... AN UPPER LEVEL RIDGE IS OVER THE NORTHERN WATERS WITH THE MEAN AXIS ALONG 32N128W TO 20N125W. VERY DRY AND STABLE AIR IS NOTED ON WATER VAPOR SATELLITE IMAGERY N OF 20N E OF THE RIDGE AXIS. AN UPPER LEVEL TROUGH IS INTRUDING ON THE FAR NW CORNER OF THE DISCUSSION AREA EXTENDING FROM AN UPPER CYCLONIC CIRCULATION NEAR 31N148W TO 24N137W. MID TO UPPER LEVEL MOISTURE IS BEING ADVECTED AHEAD OF THIS TROUGH N OF 24N W OF 135W WITH THE AID OF A 50-70 KT JET CORE. AN UPPER LEVEL TROUGH REACHES FROM 20N117W TO 10N127W WITH MOISTURE BEING TRANSPORTED FROM THE ITCZ NORTHEASTWARD WITHIN 360-420 NM E OF THE TROUGH. AN UPPER LEVEL ANTICYCLONE IS OVER MEXICO NEAR 16N97W. DIFFLUENCE ALOFT IS ENHANCING CONVECTION ALONG THE MONSOON TROUGH AS IS DESCRIBED IN THE SECTION ABOVE. IN THE DEEP TROPICS...AN UPPER LEVEL CYCLONIC CIRCULATION HAS SHIFTED S OF THE EQUATOR TO NEAR 02S117W WITH AN UPPER LEVEL TROUGH REACHING INTO THE AREA TO 06N116W. NW OF THE CYCLONIC CIRCULATION IS A BROAD UPPER LEVEL ANTICYCLONE POSITIONED NEAR 10N126W. AT THE SURFACE...1029 MB HIGH PRES IS NW OF THE AREA NEAR 36N135W WITH A RIDGE AXIS EXTENDING INTO THE AREA NEAR 32N130W TO 15N103W. EARLIER SCATTEROMETER PASSES AND SHIP OBSERVATIONS INDICATED AN AREA OF FRESH NE-E TRADES FROM 10N TO 15N W OF 130W. MIXED NE AND NW SWELL OF 8-9 FT SURROUNDS THESE TRADES ACROSS THE REGION FROM 09N TO 16N W OF 120W. THESE TRADES AND SWELL WILL GRADUALLY DIMINISH AND SUBSIDE BY 36 HOURS. AN AREA OF 8-10 FT NW SWELL IS OVER THE FAR N CENTRAL WATERS N OF 25N BETWEEN 119W AND 128W. THIS SWELL WILL SUBSIDE TO LESS THAN 8 FT BY 36 HOURS. A 1008 MB LOW PRES CENTER IS ANALYZED ALONG THE MONSOON TROUGH NEAR 09N91.5W AND IS DRIFTING W. ENHANCED FRESH SW MONSOONAL FLOW WITH SEAS TO 9 FT IS TO THE S-SW OF THIS LOW FROM 05N TO 08N BETWEEN 90W AND 96W...AS CAPTURED BY A 1608 UTC ASCAT PASS AND A 1620 UTC JASON-2 ALTIMETER PASS. NO SIGNIFICANT DEVELOPMENT OF THIS LOW IS ANTICIPATED DURING THE NEXT 48 HOURS. A COUPLE OF SURFACE TROUGHS ARE ANALYZED ALONG THE ITCZ. THE FIRST EXTENDS FROM 14N117W TO 08N120W. THE SECOND TROUGH IS TO THE W EXTENDING FROM 12N133W TO 06N135W. ASSOCIATED CONVECTION IS AS DESCRIBED IN THE SECTION ABOVE. A TIGHT PRES GRADIENT WILL BECOME ESTABLISHED OVER THE NW MEXICO REGION AND NW-N 20 KT WINDS ARE EXPECTED IN THE GULF OF CALIFORNIA FROM 26N TO 29N COMMENCING LATE TONIGHT...DIMINISHING BY LATE THU NIGHT. GAP WINDS...HIGH PRES WILL BUILD IN BEHIND A COLD FRONT WHICH WILL MOVE THROUGH THE SW GULF OF MEXICO ON THU. STRONG NORTHERLY WINDS WILL FILTER FROM THE GULF OF MEXICO THROUGH THE CHIVELA PASS TO ACROSS THE GULF OF TEHUANTEPEC...AND A GALE WARNING REMAINS IN EFFECT FROM THU EVENING THROUGH AT LEAST FRI AFTERNOON. $$ LEWITSKY