000 AXPZ20 KNHC 131505 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC FRI MAY 13 2016 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 1430 UTC. ...INTERTROPICAL CONVERGENCE ZONE... THE MONSOON TROUGH EXTENDS FROM 08N96W TO 1010 MB LOW PRES NEAR 07N108W TO 1008 MB LOW PRES NEAR 10N115W TO 07N118W. THE ITCZ AXIS EXTENDS FROM 07N118W TO 05N135W TO 05N140W. WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 120 NM EITHER SIDE OF A LINE FROM 05N95W TO 10N105W. SCATTERED MODERATE CONVECTION IS FROM 04N TO 14N BETWEEN 111W AND 119W...AND FROM 04N TO 07N BETWEEN 134W AND 139W. ...DISCUSSION... THE 1023 MB SUBTROPICAL HIGH WAS ANALYZED NEAR 30N126W WITH A RIDGE AXIS EXTENDING SE TO NEAR 20N110W. THE SUBTROPICAL HIGH HAS BEEN WEAKENED BY A DEEP-LAYERED LOW TO ITS NW...WELL N OF THE AREA NEAR 39N137W. THE LOW EXTENDS A WEAKENING STATIONARY FRONT INTO THE FORECAST AREA FROM 32N133W TO 26N140W THAT IS EXPECTED TO DISSIPATE TONIGHT. THE HIGH WILL CONTINUE TO WEAKEN AS THE LOW PASSES N OF IT TODAY AND TONIGHT BEFORE GRADUALLY COMBINING WITH SURFACE HIGH PRES MOVING IN BEHIND THE LOW SAT INTO SAT NIGHT. TRADE WINDS ARE CURRENTLY AT MODERATE TO FRESH BREEZE LEVEL ACROSS MUCH OF THE PACIFIC SW OF THE RIDGE AXIS. THE AREA OF FRESH NE TRADE WINDS SHOULD EXPAND AS THE HIGH PRES SYSTEMS COMBINE SAT AND SAT NIGHT. AN EARLIER 13/0444 UTC ASCAT-A PASS CAPTURED A BROAD LOW-LEVEL CIRCULATION ASSOCIATED WITH THE 1008 MB LOW PRES SYSTEM ANALYZED NEAR 10N115W. THE ASCAT PASS SHOWED A FRESH TO STRONG BREEZE WITHIN 60 NM NE AND SW QUADRANTS AS WELL AS WITHIN 150 NM NW QUADRANT. THIS LOW IS FORECAST TO GRADUALLY WEAKEN AS IT MOVES W- SW AROUND 12 KT DURING THE NEXT DAY OR SO. WINDS NEAR THE LOW ARE EXPECTED TO WEAKEN BELOW 20-25 KT TONIGHT AS THE PRES GRADIENT RELAXES A BIT. HOWEVER...AS MENTIONED ABOVE...THE AREA OF FRESH TRADE WINDS WILL EXPAND SAT AND SAT NIGHT AS THE RIDGE TO THE N STRENGTHENS. THE AREA OF LOW PRES SHOULD CONTINUE TO CONVERGE LOW-LEVEL MOISTURE AND SUPPORT CONVECTION THROUGH THE END OF THE PERIOD EARLY SUN. GAP WINDS... GULF OF CALIFORNIA...THE AFOREMENTIONED DEEP-LAYER LOW ENCROACHING UPON THE SUBTROPICAL HIGH WILL MOVE INTO THE WESTERN UNITED STATES SAT AND SEND A COLD FRONT THROUGH THE GREAT BASIN LATE SAT THROUGH EARLY SUN. THE GRADIENT WILL BUILD BETWEEN HIGH PRES BEHIND THE FRONT AND LOWER PRES TO THE S OVER WESTERN MEXICO...WITH A FRESH TO STRONG S-SW BREEZE EXPECTED OVER THE GULF OF CALIFORNIA N OF 30N NEAR THE END OF THE FORECAST PERIOD AT 06Z SUN. GULF OF TEHUANTEPEC...NORTHERLY FLOW IS BEING DIRECTED THROUGH THE CHIVELA PASS BETWEEN TROUGHING ACROSS THE SW GULF OF MEXICO AND HIGH PRES OVER NE AND E-CENTRAL MEXICO. NORTHERLY WINDS IN THE GULF OF TEHUANTEPEC ARE 20-30 KT THIS MORNING AS NOCTURNAL DRAINAGE FLOW ENHANCES THE WIND. BOTH THE NOCTURNAL DRAINAGE FLOW THROUGH CHIVELA PASS AND THE DIURNAL PROGRESSION OF TROUGHING MOVING NW OFF THE YUCATAN PENINSULA INTO THE SW GULF OF MEXICO WILL INFLUENCE THE WIND IN THE GULF OF TEHUANTEPEC... WITH THE STRONGEST WINDS EXPECTED TO REMAIN BELOW GALE FORCE AND OCCUR IN THE EARLY MORNING HOURS. SEAS ARE TO 8 FT THIS MORNING...BUT ARE EXPECTED TO BUILD AS HIGH AS 10-11 FT SAT MORNING. THE PRES GRADIENT SHOULD RELAX SOME BY EARLY SUN MORNING...WITH WINDS TO 25 KT EXPECTED TO BE CONFINED N OF 14N AND SEAS 8 FT. GULF OF PAPAGAYO...NE TRADE WINDS IN THE SW CARIBBEAN WILL CONTINUE TO SEEP THROUGH CENTRAL AMERICA INTO THE GULF OF PAPAGAYO THROUGH THE FORECAST PERIOD. NOCTURNAL DRAINAGE FLOW WILL ENHANCE THE WINDS...WITH A FRESH TO STRONG BREEZE EXPECTED IN THE GULF OF PAPAGAYO THIS MORNING AND SAT MORNING BEFORE DIMINISHING. SEAS ARE EXPECTED TO REACH TO 8 FT. $$ HUFFMAN