000 AXPZ20 KNHC 060930 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC FRI JAN 06 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 0900 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM COLOMBIA NEAR 07N76W TO 06N78W TO 07.5N83W TO 05N92W...WHERE IT TRANSITIONS TO ITCZ... CONTINUING ON TO 03N96W TO 05N108W TO 07N124W TO 06.5N133W TO BEYOND 06N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 120 NM N OF AXIS BETWEEN 95W AND 130W. ...DISCUSSION... ALOFT...MIDDLE TO UPPER LEVEL RIDGING CONTINUES ACROSS MUCH OF EASTERN PORTIONS OF THE AREA...FROM NEAR 11N103W EXTENDING NW TO 32N124W. N OF 15N AND E OF THIS RIDGE LIES A MIDDLE TO UPPER LEVEL CYCLONE OVER S CENTRAL TEXAS...CUT OFF FROM THE MEAN FLOW ACROSS THE U.S. WITH A TROUGH AXIS EXTENDING S INTO SRN MEXICO. W OF THE RIDGE...A LINGERING MIDDLE TO UPPER LEVEL TROUGH EXTENDED FROM NEAR 34N136W TO SE OF THE BIG ISLAND OF HAWAII NEAR 15N153W. THE RIDGE WILL WEAKEN AND FLATTEN DURING THE NEXT 24 HOURS AS THE CUT OFF LOW SHIFTS E ACROSS THE NRN GULF...WHILE THE TROUGH TO THE W SHARPENS ANS STRENGTHENS OVER THE WEEKEND... ALLOWING THE RIDGE TO REFORM ABOUT 10 DEGREES TO THE W BY SUNDAY. AT LOWER LEVELS...A 1031 MB HIGH PRES IS CENTERED N OF THE AREA NEAR 39N133W WITH RIDGE EXTENDING SE TO NEAR 19N115W. THE PRESSURE GRADIENT BETWEEN THE HIGH PRESSURE AND LOWER PRESSURE IN THE VICINITY OF THE ITCZ TO THE S IS MAINTAINING A NARROW ZONE OF FRESH TRADEWINDS FROM 06N TO 10N W OF 118W...WHILE THIS ZONE BROADENS FROM 07N TO 22N W OF 138W. SEAS AREA NEAR 8 FT ACROSS THIS AREA E OF 130W...AND IN THE 9 TO 13 FT RANGE W OF 130W...AS LARGE LONG PERIOD NW SWELL CONTINUES TO MOVE INTO THE AREA. THESE LONG PERIOD NW SWELL ARE CREATING SEAS OF 8 TO 14 FT ACROSS THE NW HALF OF THE AREA THIS MORNING...AND WILL MOVE SE AND GRADUALLY FADE BY SUN. GULF OF TEHUANTEPEC...DESPITE THE FACT THAT WINDS HAVE VEERED E TO SE OVER THE W GULF OF MEXICO...NLY WINDS CONTINUE TO FUNNEL THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC DUE TO THE RELATIVE DIFFERENCE IN AIR DENSITY BETWEEN THE AIRMASS OVER THE GULF OF MEXICO AND THAT OVER THE EASTERN PACIFIC. THIS IS RESULTING IN 20-25 KT WINDS WITH GUSTS TO 30 KT THROUGH THE GULF OF TEHAUNTEPEC. NELY WINDS CONTINUE DOWNSTREAM BEYOND 100W AND CONTINUE TO CONVERGE N OF THE ITCZ...FORCING MODEST CONVECTION ALONG AND N OF THE ITCZ MENTIONED ABOVE. AS THE AIR MASS ACROSS THE GULF OF MEXICO MODIFIES FURTHER...WIND SPEEDS WILL TREND DOWNWARD OVER THE GULF OF TEHUANTEPEC...WITH WINDS EXPECTED TO DIMINISH BELOW 20 KT BY THIS EVENING. GULF OF PAPAGAYO...FRESH TO STRONG NORTHEASTERLY GRADIENT WIND FLOW OVER THE WESTERN CARIBBEAN IS FLOWING THROUGH THE GAP IN THE TOPOGRAPHY OVER NICARAGUA AND ACROSS THE GULF OF PAPAGAYO. THIS IS EXPECTED TO CONTINUE FOR AT LEAST ANOTHER 24 HOURS...WITH WINDS PEAKING NEAR 25 KT DURING THE EARLY MORNING HOURS WITH THE ADDED COMPONENT OF NOCTURNALLY DRIVEN KATABATIC WINDS. ELSEWHERE E OF 110W...N TO NE SWELL ASSOCIATED WITH THE COMBINED STRONG GAP FLOW FROM PAPAGAYO AND TEHUANTEPEC COVERS MUCH OF THE AREA S OF 15N BETWEEN 93W AND 120W. THESE SWELLS ARE MIXING WITH NW SWELL W OF 100W AND CAUSING CONFUSED SEAS. SEAS ACROSS THE AREA BETWEEN 100W AND 120W WILL BUILD TO 8 TO 10 FT THROUGH SUNDAY AS THE NW SWELL PROPAGATES THROUGH THE REGIONAL WATERS. HIGH PRESSURE IS FORECAST TO MOVE INTO THE NW U.S. OVER THE WEEKEND AND BUILD S INTO NRN MEXICO LATE SAT NIGHT INTO SUN. THIS WILL TIGHTEN THE PRES GRADIENT THROUGH THE GULF OF CALIFORNIA AND LEAD TO NWLY WINDS INCREASING TO 20 TO 25 KT SUN AND SUN NIGHT...BEFORE GRADUALLY DIMINISHING MON. $$ STRIPLING