000 AXPZ20 KNHC 120919 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC WED MAR 12 2014 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 0830 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...A COLD FRONT WILL MOVE OFF THE TEXAS COAST LATER THIS MORNING...THEN SWEEP SOUTHWARD ACROSS THE WESTERN GULF OF MEXICO THROUGH TONIGHT. THE DENSER AIRMASS BEHIND THE FRONT WILL FUNNEL ACROSS THE TEHUANTEPEC ISTHMUS AND INTO THE GULF OF TEHUANTEPEC EARLY THU MORNING...BRINGING WINDS TO GALE FORCE WITH SEAS BUILDING TO 15 FT BY MIDDAY. THE WINDS AND SEAS WILL GRADUALLY DIMINISH INTO FRI AS THE HIGH PRES BEHIND THE FRONT SHIFTS EASTWARD ACROSS THE NORTHERN GULF OF MEXICO. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A WEAK MONSOON TROUGH EXTENDS FROM 04N77W TO 02N85W TO 02N90W. THE ITCZ AXIS EXTENDS FROM 02N90W TO 01N125W TO 04N140W. THE ITCZ RESUMES AT 08N134W TO BEYOND 09N140W. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 60 NM S OF ITCZ AXIS BETWEEN 95W AND 105W. ...DISCUSSION... BESIDES THE TEHUANTEPEC GAP WIND EVENT...THE HIGH PRES THAT WILL BUILD BEHIND THE FRONT MOVING THROUGH THE GULF OF MEXICO WILL INITIATE FRESH TO STRONG GAP WINDS THROUGH THE GULF OF PAPAGAYO THU NIGHT INTO FRI MORNING...WITH ANOTHER PULSE FRI NIGHT INTO SAT MORNING. SIMILARLY...STRONG TRADE WINDS OVER THE SW CARIBBEAN WILL PUSH THROUGH PANAMA FRI INTO SAT. A LARGE PLUME OF SHORT PERIOD NE SWELL RANGING FROM 8 TO 12 FT GENERATED BY THE TEHUANTEPEC EVENT WILL MIX WITH LONGER PERIOD NW SWELL OVER THE WATERS FROM 10N TO 14N BETWEEN 94W AND 105W BY EARLY FRI. THIS WILL DECAY BELOW 8 FT THROUGH FRI. HIGH PRES N OF THE AREA OVER THE GREAT BASIN AND ROCKIES WILL ALLOW A BRIEF PULSE OF FRESH TO STRONG NW WINDS INTO THE GULF OF CALIFORNIA FROM THIS MORNING INTO THE AFTERNOON. THE WINDS WILL DIMINISH LATE TODAY AND TONIGHT AS THE RIDGE N OF THE AREA WEAKENS. A MID/UPPER LEVEL TROUGH IS MOVING ACROSS THE CENTRAL GULF OF MEXICO THIS MORNING. THE SOUTHERN EXTENT OF THIS TROUGH INTERACTED WITH THE HIGHER TERRAIN OVER GUATEMALA TO PRODUCE A FEW THUNDERSTORMS OVER THE MOUNTAINS THAT HAVE SINCE MOVED OFF THE PACIFIC COAST DUE TO OVERNIGHT DRAINAGE EFFECTS. DIVERGENCE ALOFT ASSOCIATED WITH A BROAD AND NEGATIVELY TILTED UPPER TROUGH EXTENDING FROM 20N115W TO 00N105W IS ENHANCING SCATTERED CONVECTION ALONG THE ITCZ BETWEEN 95W AND 105W. A SPLIT FLOW PATTERN ALOFT IS SETTING UP N OF THE HAWAIIAN ISLANDS...WITH THE SOUTHERN STREAM JET DIGGING SHARPLY TO THE SOUTH ALONG 145W TO 10N. DIVERGENCE ALOFT AHEAD OF THE TROUGH IS CREATING AREAS OF SHOWERS AND THUNDERSTORMS OVER THE WESTERN PORTION OF THE DISCUSSION AREA FROM 08N TO 15N W OF 135W. TRADE WIND FLOW REMAINS FAIRLY LIGHT SOUTH OF A WEAK RIDGE DISPLACED WELL N OF THE AREA. A PAIR OF ALTIMETER PASSES FROM THE PAST SEVERAL HOURS CONFIRM WAVEWATCH III INITIALIZATIONS SHOWING 6 TO 7 FT SEAS OVER A LARGE AREA W OF 110W. THIS IS THE DECAYING REMNANTS OF NW SWELL THAT MOVED INTO THE AREA SEVERAL DAYS AGO. GUIDANCE SHOWS A NEW TRAIN OF NW SWELL WILL PASS 30N140W OVER THE NEXT SEVERAL HOURS...WITH THE LEADING EDGE OF SEAS 8 FT OR GREATER REACHING AS FAR SE AS A LINE FROM 30N125W TO 25N140W BY LATE TODAY...DECAYING TO LESS THAN 8 FT THROUGH THU. LOOKING AHEAD FOR THE NEXT SEVERAL DAYS...A MID/UPPER TROUGH WILL MOVE ACROSS THE WATERS N OF 20N...PASSING E OF 120W BY SAT. THIS WILL BE IN PHASE WITH THE SOUTHERN STREAM TROUGH THAT CUTS OFF NEAR 15N130W BY SAT. TRADE WIND FLOW WILL INCREASE THU THROUGH SAT FROM 10N TO 20N W OF 120W AS DEEP LAYER RIDGING BUILDS TO THE WEST OF THE UPPER TROUGHS. DESPITE HIGH DEEP LAYER MOISTURE...AND WHILE THE INCREASED TRADE WINDS MAY ENHANCE CONVECTION SOUTH OF 10N ALONG THE ITCZ...THE ANOMALOUSLY STRONG WESTERLY JET ALOFT WILL APPLY WESTERLY SHEAR ACROSS THE MAIN AREA OF CONVERGENCE. $$ CHRISTENSEN