000 AXPZ20 KNHC 110937 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC TUE AUG 11 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 0800 UTC. ...TROPICAL WAVES... A TROPICAL WAVE ALONG 88W N OF 07N WAS MOVING W AROUND 5 KT. SCATTERED MODERATE CONVECTION WAS WITHIN 180 NM W OF THE WAVE N OF 10N AND E OF THE WAVE FROM 08N-10N. A TROPICAL WAVE ALONG 104W FROM 08N-14N WAS MOVING W AROUND 15 KT. SCATTERED MODERATE CONVECTION WITHIN 120 NM W OF THE WAVE FROM 10N-12.5N. A TROPICAL WAVE ALONG 125W FROM 04N-11N WAS MOVING W AROUND 10- 15 KT. SCATTERED MODERATE TO STRONG CONVECTION WITHIN 210 NM E OF THE WAVE FROM 06N-09N AND WITHIN 270 NM W OF THE WAVE FROM 05N-09N. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 09N78W TO 09N105W TO 08N113W TO 08N123W. THE ITCZ AXIS WAS ANALYZED FROM 07N127W TO 05N132W TO 05N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 270 NM S OF THE AXIS BETWEEN 90W-95W. SCATTERED MODERATE CONVECTION WAS WITHIN 210 NM S OF THE AXIS BETWEEN 109W-119W. SCATTERED MODERATE CONVECTION WAS WITHIN 210 NM S OF THE AXIS BETWEEN 129W- 132W. ...DISCUSSION... SCATTERED MODERATE TO STRONG CONVECTION WAS OBSERVED WITHIN 120 NM SE SEMICIRCLE OF 1008 MB LOW PRES ANALYZED NEAR 16.5N129.5W. 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. AN ASCAT-B PASS FROM 1842 UTC SHOWED WINDS TO THE ADVISORY CRITERIA OF 20-25 KT WITHIN 120 NM E SEMICIRCLE OF THE LOW. THE PASS AT 0550 UTC MISSED THE EASTERN SIDE OF THE SYSTEM...BUT THE PERSISTENT CONVECTION HAS MOVED CLOSER TO THE LOW-LEVEL CENTER SINCE THAT TIME. THE SYSTEM IS MOVING AWAY FROM AN UPPER LOW TO ITS NE NEAR 20N116W WHICH HAD BEEN PROPELLING DRIER AIR IN THE MID- AND UPPER-LEVELS TOWARD THE SYSTEM. HOWEVER...N-NW SHEAR IS EXPECTED TO TAKE A TOLL ON THE SYSTEM OVER THE NEXT DAY OR SO...WITH WINDS EXPECTED TO DROP BELOW THE ADVISORY CRITERIA OF 20-25 KT BY THIS EVENING. A SURFACE RIDGE THROUGH THE AREA FROM 32N131W THROUGH 22N123W TO 12N107W. 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. 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 AS THE PRESSURE GRADIENT REMAINS RELATIVELY UNCHANGED. 15-17 SECOND PERIODS CROSS-EQUATORIAL SWELL HAS REACHED THE COAST OF SOUTHERN MEXICO AND CENTRAL AMERICA. COMBINED SEAS IN THE 8-11 FT RANGE PRIMARILY IN S SWELL CAN BE FOUND ACROSS MUCH OF THE AREA S OF 06N BETWEEN 81W AND 105W AND S OF 03N W OF 105W. SEAS IN THIS RANGE WILL CONTINUE TO MARCH N OVER EASTERN WATERS TO 09N BY EARLY WED BEFORE SUBSIDING...WITH SEAS TO 8 FT CONFINED PRIMARILY W OF THE GALAPAGOS ISLANDS BY EARLY THU. GAP WINDS... GULF OF TEHUANTEPEC...A SURFACE RIDGE ACROSS THE GULF OF MEXICO WILL SHIFT SOUTHWARD BEGINNING TODAY AS A COLD FRONT MOVES INTO THE U.S. NORTHERN GULF COAST STATES. AT THE SAME TIME...A TROPICAL WAVE WILL PASS S OF THE GULF OF TEHUANTEPEC...INCREASING THE TROUGHING THERE. THIS WILL INCREASE THE PRESSURE GRADIENT ACROSS SOUTHERN MEXICO AND ALLOW N WINDS TO FUNNEL THROUGH CHIVELA PASS BEGINNING EARLY WED. WINDS WILL REACH A FRESH TO STRONG BREEZE WITH THE ASSISTANCE OF NOCTURNAL DRAINAGE FLOW BOTH WED AND THU MORNINGS. SOUTHERLY SWELL COUPLED WITH THE GAP WIND GENERATED SWELL WILL QUICKLY BUILD SEAS TO 8-10 FT WED...WITH SEAS EXPECTED TO REMAIN AT OR ABOVE 8 FT THROUGH THE END OF THE FORECAST PERIOD EARLY THU MORNING. GULF OF PAPAGAYO...THE SAME PATTERN DESCRIBED IN THE GULF OF TEHUANTEPEC SECTION ABOVE WILL FORCE FRESH TO STRONG E-NE WINDS THROUGH THE GULF OF PAPAGAYO BY EARLY WED. THESE WINDS WILL PULSE...BECOMING STRONGEST IN THE MORNING HOURS WITH THE BENEFIT OF NOCTURNAL DRAINAGE FLOW BOTH WED AND THU MORNINGS. SEAS WILL ALSO QUICKLY BUILD TO 9 FT HERE WED WHEN COMBINED WITH S SWELL...AND REMAIN IN THE 7-9 FT RANGE DOWNSTREAM OF PAPAGAYO THROUGH THE END OF THE FORECAST PERIOD. $$ SCHAUER