000 AXPZ20 KNHC 121537 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC WED AUG 12 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1400 UTC. ...TROPICAL WAVES... A TROPICAL WAVE ALONG 96W FROM 06N TO 14N IS MOVING W AT 15 KT. SCATTERED MODERATE CONVECTION FROM 10N TO 16N BETWEEN 90W AND 96W. A TROPICAL WAVE ALONG 117W FROM 08N TO 16N IS MOVING W AT 15 KT. ISOLATED MODERATE CONVECTION IS FROM 06N TO 11N BETWEEN 113W TO 117W. A TROPICAL WAVE ALONG 131W FROM 04N TO 14N MOVING W AT 15 KT. SCATTERED MODERATE CONVECTION IS WITHIN 240 NM W OF WAVE FROM 09N TO 14N. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH AXIS EXTENDS FROM 07N78W TO 09N94W TO 08N104W TO 08N118W. ITCZ AXIS EXTENDS FROM 08N118W TO 10N128W TO 07N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM 03N TO 07N E OF 85W. SCATTERED MODERATE CONVECTION IS FROM 05N TO 15N BETWEEN 98W AND 107W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 05N TO 09N BETWEEN 132W AND 136W. ...DISCUSSION... A 1009 MB LOW IS NEAR 18N133W MOVING W AT 10 KT. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 14N TO 19N BETWEEN 131W AND 134W. A 0924 UTC WINDSAT WENT OVER THE LOW AND SHOWED 20 TO 25 KT WINDS. NUMERICAL MODEL GUIDANCE SHOWS THE NW SHEAR OVER THE SYSTEM SHOULD NOT GET ANY WORSE OVER THE NEXT TWO DAYS. HOWEVER...THE MODELS SUGGEST THAT THE LOW PRES SYSTEM WILL OPEN UP TO A TROUGH BY LATE THU...AND WINDS WILL DIMINISH AS THE SYSTEM BEGINS TO MOVE OVER COLDER WATER. CONFIDENCE IS LOW IN THE FORECAST AS THIS SYSTEM HAS DEFIED THE MODEL GUIDANCE THE PAST FEW DAYS. A SURFACE RIDGE FROM A 1018 MN HIGH AT 29N126W TO 20N114W. THE PRESSURE GRADIENT BETWEEN THIS RIDGE AND TROUGHING IN THE VICINITY OF THE GULF OF CALIFORNIA IS SUPPORTING A MODERATE TO FRESH BREEZE ON THE PACIFIC COAST OF THE BAJA CALIFORNIA PENINSULA DURING THE EVENING AND NIGHT HOURS. WINDS ARE GENTLE TO MODERATE BREEZE DURING THE DAY. CROSS-EQUATORIAL S-SW SWELL ACROSS MUCH OF THE AREA WILL GRADUALLY SUBSIDE THROUGH THE END OF THE FORECAST PERIOD EARLY FRI MORNING. COMBINED SEAS IN THE 8-10 FT RANGE CAN BE FOUND ACROSS MUCH OF THE AREA S OF A LINE FROM 09N84W TO 09N100W TO 00N120W...EXCEPT IN THE LEE OF THE GALAPAGOS ISLANDS. SEAS WILL GRADUALLY SUBSIDE THROUGH EARLY FRI. GAP WINDS... GULF OF TEHUANTEPEC...THE PRESSURE GRADIENT BETWEEN A SURFACE RIDGE ACROSS THE GULF OF MEXICO DISPLACED SOUTHWARD BY A STATIONARY FRONT OVER THE U.S. GULF OF MEXICO COASTAL STATES AND A TROPICAL WAVE S OF THE GULF OF TEHUANTEPEC HAS ALLOWED N WINDS TO FUNNEL THROUGH CHIVELA PASS. A FRESH TO STRONG N-NE BREEZE SHOULD CONTINUE HERE THROUGH THU MORNING AS THE WAVE PASSES TO THE SW AND WITH THE ASSISTANCE OF NOCTURNAL DRAINAGE FLOW...ONLY TO RETURN EARLY FRI MORNING. SOUTHERLY SWELL COUPLED WITH THE GAP WIND GENERATED SWELL WILL QUICKLY BUILD SEAS TO 8-10 FT TODAY...WITH SEAS AT OR ABOVE 8 FT EXPECTED TO TRACK W AS FAR AS 106W BEHIND THE WAVE. GULF OF PAPAGAYO...THE SAME PATTERN DESCRIBED IN THE GULF OF TEHUANTEPEC SECTION IS FORCING FRESH TO STRONG E-NE WINDS THROUGH THE GULF OF PAPAGAYO. THESE WINDS WILL PULSE...BECOMING A FRESH TO STRONG BREEZE IN THE MORNING HOURS THU WITH THE BENEFIT OF NOCTURNAL DRAINAGE FLOW BEFORE THE PRESSURE GRADIENT WEAKENS. SEAS TO 9 FT HERE IN COMBINED NE WIND WAVES AND S SWELL...WILL SPREAD W BEHIND THE TROPICAL WAVE TODAY...BUT BECOME MORE CONFINED TO THE GULF OF PAPAGAYO THU. WINDS AND SEAS WILL DIMINISH AFTER SUNRISE THU. $$ FORMOSA