000 AXPZ20 KNHC 140309 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC FRI FEB 14 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0115 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 04N77W TO 09N85W TO 05N96W. THE ITCZ AXIS WAS ANALYZED FROM 05N96W TO 07N133W TO 07N140W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS FROM 03N TO 07N BETWEEN 80W AND 85W. SCATTERED MODERATE CONVECTION WAS FROM 08N TO 11N BETWEEN 122W AND 128W. ...DISCUSSION... THE 1023 MB SUBTROPICAL HIGH NEAR 32N129W EXTENDS A RIDGE AXIS THROUGH THE FORECAST AREA TO NEAR 20N110W. THE OSCAT PASS FROM AROUND 1945 UTC SHOWS MODERATE TO FRESH NE TRADE WINDS LIE OVER WATERS W OF 130W JUST N OF THE ITCZ. SEAS TO 9 FT PRIMARILY IN NE TRADE WIND SWELL CAN BE FOUND OVER MUCH OF THE AREA FROM 08N TO 18N W OF 133W AS OBSERVED BY A 1930 UTC JASON PASS. THE HIGH IS FORECAST TO REMAIN QUASI-STATIONARY THROUGH FRI AS IT IS ENCROACHED UPON BY A COLD FRONT CURRENTLY FOUND TO ITS NW. WITHOUT FRESH TO STRONG TRADE WINDS IN PLACE...THE NE TRADE WIND SWELL WILL SUBSIDE BELOW 8 FT BY FRI AFTERNOON. THE FRONT IS EXPECTED TO MOVE INTO THE FAR NW CORNER OF THE FORECAST AREA BY EARLY SAT MORNING. NW SWELL ASSOCIATED WITH THE FRONT WILL BRING SEAS TO 11 FT INTO THE NW CORNER OF THE AREA BY THE END OF THE FORECAST PERIOD SAT EVENING. SOUTHWEST FLOW ON THE S SIDE OF A MID- TO UPPER-LEVEL LOW NEAR 15N130W IS TAPPING INTO DEEP LAYERED TROPICAL MOISTURE POOLED ALONG THE ITCZ W OF 120W AS SEEN IN PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION WAS FROM 08N TO 11N BETWEEN 122W AND 128W...EMBEDDED IN AN AREA OF MULTI-LAYERED CLOUDS WITH ISOLATED SHOWERS GENERALLY FOUND N OF THE ITCZ TO 20N BETWEEN 120W AND 130W. THE LOW IS FORECAST TO DIP SOUTHWARD ABOUT 5 DEGREES ALONG 130W THROUGH SAT...BUT NO SIGNIFICANT CHANGE IS EXPECTED IN THE PRECIPITATION ALONG THE ITCZ HERE OVER THE NEXT FEW DAYS. BROAD UPPER DIFFLUENCE IS ENHANCING THE SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION FOUND FROM 03N TO 07N BETWEEN 80W AND 85W. THIS AREA NEAR THE EASTERN PORTION OF THE MONSOON TROUGH HAS THE HIGHEST PRECIPITABLE WATER VALUES WITHIN THE FORECAST AREA. DIFFLUENCE HERE IS ATTRIBUTED TO AN UPPER RIDGE AXIS THAT SPANS FROM AN ANTICYCLONE OVER WESTERN VENEZUELA TO A SECOND ANTICYCLONE JUST NE OF THE GALAPAGOS ISLANDS. THE RIDGE AXIS IS EXPECTED TO REMAIN IN PLACE HERE THROUGH SAT EVENING...SO THE EASTERN PORTION OF THE MONSOON TROUGH SHOULD CONTINUE TO BE A FOCUS FOR MODERATE TO HEAVY PRECIPITATION OVER THE NEXT TWO DAYS. GULF OF TEHUANTEPEC...THE OSCAT PASS FROM NEAR 1800 UTC SHOWED WINDS HAVE DIMINISHED TO A FRESH TO STRONG BREEZE IN THE GULF OF TEHUANTEPEC. HIGH PRESSURE IN THE GULF OF MEXICO WILL SHIFT EASTWARD OVERNIGHT...WEAKENING THE PRESSURE GRADIENT THROUGH CHIVELA PASS. WINDS IN THE GULF OF TEHUANTEPEC ARE EXPECTED TO DIMINISH TO 20 KT OR LESS BY SUNRISE FRI. A FRESH TO STRONG N BREEZE WILL RETURN SAT AFTERNOON AS HIGH PRES ONCE AGAIN BUILDS IN THE NW GULF OF MEXICO BEHIND A FAST MOVING COLD FRONT...INCREASING THE PRESSURE GRADIENT THROUGH CHIVELA PASS BETWEEN THE HIGH AND THE MONSOON TROUGH TO THE S. GULF OF PAPAGAYO...WINDS IN THE GULF OF PAPAGAYO ARE ONLY A GENTLE TO MODERATE NE BREEZE AT THE MOMENT BUT ARE EXPECTED TO BECOME A STRONG BREEZE FRI MORNING AS THE PRESSURE GRADIENT BUILDS OVER CENTRAL AMERICA AND NOCTURNAL DRAINAGE FLOW IS AT ITS PEAK. WINDS WILL DIMINISH BELOW 25 KT BY FRI AFTERNOON...BUT WILL AGAIN PULSE TO A STRONG BREEZE SAT MORNING. $$ SCHAUER