000 AXPZ20 KNHC 120931 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0815 UTC. ...TROPICAL WAVES... A TROPICAL WAVE ALONG 95W FROM 06N TO 14N WAS MOVING W AROUND 15 KT. SCATTERED MODERATE CONVECTION WAS WITHIN 180 NM W OF WAVE FROM 08N-10N. A TROPICAL WAVE ALONG 115W FROM 08N-16N WAS MOVING W AROUND 10- 15 KT. SCATTERED MODERATE CONVECTION WAS FROM 06N-11N BETWEEN 112W-116W. A TROPICAL WAVE ALONG 131W FROM 04N-12N WAS MOVING W AROUND 10- 15 KT. SCATTERED MODERATE CONVECTION WAS WITHIN 240 NM W OF WAVE FROM 06N-09N. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 09N83W TO 10N97W TO 07N115W. ITCZ AXIS WAS ANALYZED FROM 07N115W TO 09N125W TO 06N140W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS FROM 04N-08N E OF 84W. SCATTERED MODERATE CONVECTION WAS WITHIN 240 NM S OF THE AXIS BETWEEN 100W-106W AND WITHIN 300 NM N OF THE AXIS BETWEEN 122W-127W. ...DISCUSSION... SCATTERED MODERATE TO STRONG CONVECTION WAS WITHIN 75 NM N QUADRANT...120 NM SE QUADRANT AND 45 NM W SEMICIRCLE OF 1009 MB LOW PRES ANALYZED NEAR 17.5N132.5W. THE LAST VISIBLE IMAGES AVAILABLE AROUND 0300 UTC SHOWED A WELL-DEFINED EXPOSED LOW- LEVEL CENTER ON THE WESTERN SIDE OF THE PERSISTENT DEEP CONVECTION. SINCE THEN...THE CONVECTION HAS INTENSIFIED AND HAS WRAPPED AROUND THE LOW-LEVEL CENTER. THE MOST RECENT SCATTEROMETER PASS OVER THE SYSTEM WAS FROM RAPIDSCAT AT 2334 UTC. IT RELIABLY SHOWED 20-25 KT WINDS WITHIN 120 NM NE QUADRANT WITH A CONSIDERABLE AMOUNT OF RAIN FLAGGED VECTORS OUTSIDE OF THIS AREA IN THE E SEMICIRCLE. THE SYSTEM HAS BEEN THE RECIPIENT OF MORE LOW- TO MID-LEVEL MOISTURE OVER THE PAST 24 HOURS AS A TROPICAL WAVE HAS PASSED TO ITS S. THE SYSTEM IS FORECAST TO MOVE W-NW AROUND 5 KT OVER THE NEXT DAY OR SO. 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 THROUGH THE AREA FROM 32N137W TO THE ISLAS REVILLAGIGEDO. THE PRESSURE GRADIENT BETWEEN THIS RIDGE AND TROUGHING IN THE VICINITY OF THE GULF OF CALIFORNIA IS SUPPORTING A MODERATE NW BREEZE ON THE PACIFIC COAST OF THE BAJA CALIFORNIA PENINSULA. THESE WINDS SHOULD DIMINISH TO A GENTLE TO MODERATE BREEZE DURING THE DAYS AND INCREASE AGAIN IN THE EVENING HOURS FOR THE NEXT FEW DAYS...WITH WINDS INCREASING TO A FRESH TO STRONG BREEZE TONIGHT AND THU NIGHT AS THE RIDGE INTENSIFIES BUT REMAINS RELATIVELY STATIONARY. 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 09N BETWEEN 81W AND 100W AND S OF 03N W OF 100W. SEAS WILL GRADUALLY SUBSIDE THROUGH EARLY FRI...WITH 8 FT SEAS CONFINED TO S CENTRAL WATERS BY THAT TIME. 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...DIMINISHING AFTER SUNRISE THIS MORNING AND BECOMING A FRESH TO STRONG BREEZE AGAIN 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. $$ SCHAUER