000 AXPZ20 KNHC 271606 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC TUE DEC 27 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1545 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH AXIS FROM 08N78W TO 06N81W TO 07N100W TO 08N108W TO 08N120W WHERE LOW LEVEL WINDS SUGGEST THE ITCZ AXIS BEGINS...AND CONTINUES TO 12N125W TO 09N134W AND TO BEYOND 10N140W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 180 NM N OF THE AXIS BETWEEN 112W-118W...AND ALSO FROM 12N-18N BETWEEN 118W-125W. ...DISCUSSION... AN ANTICYCLONE CENTERED NEAR 13N105W DOMINATES MOST OF THE EASTERN SECTION OF THE DISCUSSION AREA WITH A RIDGE EXTENDING FROM IT NW TO 30N122W. ASSOCIATED BROAD ANTICYCLONIC FLOW DOMINATES THE AREA MAINLY N OF 13N AND E OF ABOUT 125W. TO THE NW OF THE ANTICYCLONIC FLOW...AN ELONGATED UPPER TROUGH CUTS SW INTO THE AREA FROM 32N130W SW TO A CUT-OFF UPPER LEVEL LOW MOVING S NEAR 20N142W. THE UPPER SW FLOW PATTERN BETWEEN THE CYCLONIC FLOW E OF THE LOW AND THE RIDGE IS ADVECTING EXTENSIVE MOSTLY MID/UPPER LEVEL CLOUDS FROM THE DEEP TROPICS N AND NE TOWARDS BAJA CALIFORNIA. IN ADDITION...UPPER LEVEL DIVERGENCE WITHIN THIS AREA IS SUSTAINING SCATTERED MODERATE TO STRONG CONVECTION THAT IS DEVELOPING ALONG AND N OF THE ITCZ BETWEEN 118W-125W. AT THE SURFACE...A 1030 MB HIGH IS CENTERED JUST N OF THE AREA AT 33N130W WITH A RIDGE SE TO NEAR 21N113W. A WEAK TROUGH MOVING SLOWLY W IS ALONG 125W FROM 10N TO 13N...AND IS AIDING CONVECTION DESCRIBED ABOVE UNDER ITCZ AND WITH THE SUPPORT OF DIVERGENCE ALOFT. THE UPPER LEVEL LOW WILL CONTINUE TO DROP SWD OVER THE NEXT 24-48 HRS...WHILE THE UPPER TROUGH SHEARS OUT AS IT BEGINS TO STRETCH FROM THE SW U.S. SW TO NEAR 32N128W. IN RESPONSE...THE ANTICYCLONE DRIFTS ESE TO NEAR 12N104W BY LATE WED WITH ANTICYCLONIC FLOW SUPPRESSED SWD TO S OF 23N AND E OF 120W. OVER THE FAR SRN PORTION OF THE AREA...AN ELONGATED UPPER CYCLONE IS CENTERED NEAR 06N108W. THE CYCLONE IS ON THE N EDGE OF BROAD UPPER SWLY FLOW NOTED THAT COVERS THE FAR SE PART OF THE AREA. SATELLITE WATER VAPOR IMAGERY SHOWS EXTENSIVE MODERATE SUBSIDENCE WITH STABLE ATMOSPHERIC CONDITIONS PRESENT THROUGHOUT THE EASTERN HALF OF THE AREA WITH ONLY ISOLATED WEAK CONVECTION JUST S OF THE MONSOON TROUGH BETWEEN 85W-92W. GAP WINDS... GULF OF TEHUANTEPEC...GALE FORCE WINDS THROUGH THE GULF ARE FORECAST TO DROP TO BELOW GALE FORCE IN ABOUT 6 HRS AS NOCTURNAL DRAINAGE FLOW FROM THE OVERNIGHT HOURS SUBSIDES. HOWEVER...AN ADDITIONAL WIND SURGE OVER THE GULF OF MEXICO IS EXPECTED THIS EVENING AND INTO WED WHICH WILL ONCE AGAIN INTRODUCE GALE FORCE WINDS ACROSS THE GULF OF TEHUANTEPEC ...AND WATERS JUST S OF THERE THROUGH WED AFTERNOON BEFORE AGAIN DIMINISHES EARLY WED EVENING AS WINDS OVER THE GULF OF MEXICO BEGIN TO VEER AROUND CUTTING OFF THE WIND FLOW FUNNELING INTO THE GULF OF TEHUANTEPEC. A LARGE AREA OF FRESH NE SWELL OF 8 TO 10 FT GENERATED BY THE GAP WIND FLOW ARE REACHING AS FAR WEST AS ABOUT 110W. GULF OF CALIFORNIA...THE PRESSURE GRADIENT BETWEEN PERSISTENT HIGH PRESSURE CENTER NW OF THE GULF OF CALIFORNIA...AND TROUGHING OVER MEXICO WILL MAINTAIN AREAS OF 20 KT WINDS OVER THE GULF OF CALIFORNIA THROUGH AT LEAST WED NIGHT. GULF OF PAPAGAYO...FRESH TRADEWINDS OVER THE WESTERN CARIBBEAN WILL CONTINUE TO FUNNEL INTO THE GULF OF PAPAGAYO THROUGH AT LEAST WED NIGHT. WINDS WILL PEAK DURING THE EARLY MORNING HOURS WITH THE ADDITION OF NOCTURNALLY DRIVEN KATABATIC WINDS. THE HIGH PRES OF 1030 MB IS CENTERED N OF THE AREA NEAR 33N130W WITH ITS RIDGE ARE INTERACTING WITH LOWER PRES NEAR THE ICTZ TO MAINAIN A PRES GRADIENT THAT SUPPORTS FRESH TO STRONG TRADEWINDS FROM 10N TO 25N W OF 120W AND FROM 10N TO 20N BETWEEN 110W AND 130W. THE AREA OF HIGH PRESSURE WILL PREVAIL JUST N OF THE AREA...MAINTAINING THE FRESH TO STRONG TRADEWINDS THROUGH AT LEAST WED NIGHT. NW SWELL WITH HEIGHTS TO 13 FT CONTINUES TO PROPAGATE OVER MUCH OF THE AREA W OF 115W...MIXING PRIMARILY WITH FRESH NE SWELL FROM THE PERSISTENT TRADE WIND FLOW. $$ AGUIRRE