000 AXPZ20 KNHC 170318 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE FEB 17 2015 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 0145 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...THE ASCAT-B PASS FROM 1628 UTC SHOWED N WINDS TO 30 KT FUNNELING INTO THE GULF OF TEHUANTEPEC. THE PRES GRADIENT HAS INCREASED SINCE THAT TIME...AND GALE FORCE WINDS ARE BELIEVED TO BE PRESENT IN THE GULF OF TEHUANTEPEC. THE GRADIENT BETWEEN HIGH PRES OVER NE MEXICO AND THE ITCZ TO THE S SHOULD CONTINUE TO SUPPORT MINIMAL GALE FORCE WINDS THROUGH TOMORROW AFTERNOON BEFORE INCREASING WED EVENING THROUGH THU MORNING WHEN STRONGER HIGH PRES BUILDS OVER THE GULF OF MEXICO. WINDS COULD APPROACH STORM FORCE EARLY THU MORNING AS NOCTURNAL DRAINAGE FLOW ENHANCES THE WIND. SEAS WILL BUILD AS HIGH AS 14-16 FT DURING TIME. WINDS ARE FORECAST TO DIMINISH TO MINIMAL GALE FORCE THU AFTERNOON ONLY TO RETURN TO 40 KT BY THE END OF THE FORECAST PERIOD THU EVENING. LOOKING AHEAD...GALE FORCE WINDS ARE EXPECTED TO CONTINUE INTO THE WEEKEND AS THE TIGHT PRES GRADIENT LINGERS ACROSS THE ISTHMUS OF TEHUANTEPEC. ...INTERTROPICAL CONVERGENCE ZONE... THE ITCZ AXIS WAS ANALYZED FROM 03N90W TO 04N115W TO 06N124WTO 04N132W...THEN CONTINUES FROM 06N135W TO 04N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 90 NM S OF THE AXIS BETWEEN 118W- 124W. ...DISCUSSION... AN AREA OF ENHANCED TRADE WINDS LIES NEAR A SURFACE TROUGH ANALYZED FROM 10N133W TO 03N134W...WITH 20-30 KT NE WINDS SEEN BY THE 1810 UTC ASCAT-B PASS FROM 06N-15N W OF 130W. THE HIGH PRES NE OF THE TROUGH HAS WEAKENED SINCE THAT TIME...AND WINDS ARE BELIEVED TO BE A STRONG BREEZE HERE AT BEST BASED ON THE 1948 UTC RAPIDSCAT PASS. THIS TROUGH IS PART OF THE SURFACE REFLECTION OF AN UPPER LOW NEAR 17N133W THAT IS FORECAST TO WEAKEN AND SHIFT E TO 120W THROUGH THE FORECAST PERIOD. THE ENHANCED TRADES WILL ALSO WEAKEN AND SHIFT E THROUGH WED AFTERNOON BEFORE DIMINISHING BELOW THE ADVISORY CRITERIA OF 20- 25 KT. TO THE N...A COLD FRONT NW OF THE AREA WILL SHIFT INTO NW WATERS OVERNIGHT TONIGHT. A FRESH TO STRONG NW BREEZE BEHIND THE FRONT WILL PERSIST UNTIL WED AFTERNOON WHEN THE FRONT BEGINS TO WEAKEN. CURRENTLY...NW SWELL IN THE 8-10 FT RANGE LIES ACROSS WATERS N OF 16N W OF 133W. A NEW BATCH OF NW SWELL ASSOCIATED WITH THIS FRONT WILL GRADUALLY INCREASE THE SEAS ACROSS N WATERS TO AS HIGH AS 12-15 FT N OF 29N BETWEEN 125W-135W THU EVENING. GAP WINDS... GULF OF PAPAGAYO...NOCTURNAL DRAINAGE FLOW COUPLED WITH A TIGHTENED PRES GRADIENT BETWEEN HIGH PRES TO THE N OVER NORTHWESTERN CARIBBEAN AND THE ITCZ TO THE SW SHOULD BRING A FRESH TO STRONG NE BREEZE TO THE GULF OF PAPAGAYO OVERNIGHT WITH SEAS BUILDING TO 9 FT BY SUNRISE. HIGH PRES WILL BUILD MARKEDLY N OF THE AREA BY EARLY THU MORNING. WINDS SHOULD INCREASE TO NEAR GALE FORCE DURING THE NOCTURNAL MAXIMUM OF DRAINAGE FLOW AS THE AREAL EXTENT OF THE FRESH TO STRONG NE WINDS SPREADS WELL DOWNWIND OF PAPAGAYO TO NEAR 06N102W. SEAS WILL BUILD AS HIGH AS 8-10 FT. GULF OF PANAMA...THE AFOREMENTIONED INCREASE IN RIDGING N OF THE AREA SHOULD DRIVE A STRONGER PRES GRADIENT ACROSS THE GULF OF PANAMA AS WELL. FRESH TO STRONG N WINDS ARE EXPECTED S OF THE GULF OF PANAMA TO 05N BEGINNING EARLY THU MORNING. THESE WINDS ARE EXPECTED TO WEAKEN SOME THU AFTERNOON...BUT SHOULD RETURN BY EVENING. $$ SCHAUER