000 AXPZ20 KNHC 130248 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC THU AUG 13 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0215 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 100W FROM 10N TO 17N MOVING W AT 10-15 KT. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS ON EITHER SIDE OF THE WAVE AXIS PARTICULARLY FROM 12N TO 16N BETWEEN 98W AND 102W. AN EASTERLY WIND SURGE IN THE 20-25 KT RANGE FOLLOWS THE WAVE WITH BUILDING SEAS TO AROUND 9 FT IN MIXED NE AND S SWELL. AN EARLIER SCATTEROMETER PASS CONFIRMED THE PRESENCE OF THESE WINDS. FRESH TO STRONG E-SE WINDS ARE FORECAST TO PERSIST ON THE EAST SIDE OF THE WAVE AXIS OVER THE NEXT COUPLE OF DAYS. AN AREA OF LOW PRES IS FORECAST TO FORM IN ASSOCIATION WITH THIS WAVE IN A COUPLE OF DAYS. ENVIRONMENTAL CONDITIONS SHOULD SUPPORT DEVELOPMENT OF THE LOW PRES BY LATER THIS WEEK...AND A TROPICAL CYCLONE WILL LIKELY FORM LATE THIS WEEKEND OR EARLY NEXT WEEK WHILE IT CONTINUES TO MOVE W-NW AT 10-15 KT. A TROPICAL WAVE EXTENDS FROM 16N118W TO 09N119W MOVING W AT AROUND 10 KT. MOISTURE IS LIMITED IN ASSOCIATION WITH THIS FEATURE AS DEPICTED IN THE TPW PRODUCT. ONLY A FEW SHOWERS ARE NEAR THE SOUTHERN END OF THE WAVE AXIS. A TROPICAL WAVE EXTENDS FROM 15N131W TO 09N132W MOVING W AT 10- 15 KT. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM 10N TO 12N BETWEEN 132W AND 134W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 08N78W TO 07N90W TO 09N100W TO 08N110W TO 09N117W. THE ITCZ AXIS STRETCHES FROM 09N120W TO 09N131W TO 09N140W. SCATTERED MODERATE CONVECTION ARE NOTED FROM 05N TO 07N BETWEEN 87W AND 89W...FROM 09N TO 11N BETWEEN 92W AND 96W...AND FROM 08N TO 10N BETWEEN 103W AND 106W. ISOLATED TO SCATTERED MODERATE CONVECTION IS FROM 04N TO 12N W OF 125W. ...DISCUSSION... A 1009 MB LOW PRES IS LOCATED NEAR 18.5N134W MOVING W AT 10-15 KT. VISIBLE SATELLITE IMAGES CONTINUE TO SHOW A WELL-DEFINED EXPOSED LOW-LEVEL CENTER ON THE WESTERN SIDE OF THE DEEP CONVECTION. CURRENTLY...SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED FROM 16N TO 19N BETWEEN 132W AND 134W. DEVELOPMENT OF THIS SYSTEM IS UNLIKELY DUE TO UNFAVORABLE ENVIRONMENTAL CONDITIONS...AND IT COULD OPEN UP INTO A TROUGH NEAR 140W BY LATE THU. A SURFACE RIDGE DOMINATES THE N WATERS ANCHORED ON A 1019 MB HIGH PRES LOCATED NEAR 30N125W. THE PRESSURE GRADIENT BETWEEN THIS RIDGE AND THE AFOREMENTIONED LOW PRES IS PRODUCING AN AREA OF FRESH TO LOCALLY STRONG WINDS FROM 18N TO 21N BETWEEN 131W AND 137W WITH SEAS TO 9 FT. THESE WINDS ARE FORECAST TO PERSIST ON THE NORTHERN SEMICIRCLE OF THE LOW CENTER DURING THE NEXT 24 HOURS. CROSS-EQUATORIAL SOUTHERLY SWELL CONTINUES TO PROPAGATE ACROSS MUCH OF THE REGION. COMBINED SEAS IN THE 8-9 FT RANGE CAN BE FOUND ACROSS THE SOUTH WATERS E OF THE GALAPAGOS ISLANDS FROM 01N TO 05N BETWEEN 82W AND 87W...AND W OF 94W AND S OF A LINE FROM 10N94W TO 10N101W TO 04N120W TO 04N140. SEAS WILL GRADUALLY SUBSIDE...FIRST E OF THE GALAPAGOS ISLANDS IN ABOUT 12 HOURS AND THEN W OF 94W IN ABOUT 36-48 HOURS. GAP WINDS... GULF OF TEHUANTEPEC...AS THE TROPICAL WAVE CURRENTLY LOCATED ALONG 100W CONTINUES TO MOVE WESTWARD...EXPECT PULSING FRESH TO STRONG NORTHERLY WINDS ACROSS THIS GULF OVERNIGHT TONIGHT INTO EARLY THU MORNING...AND THEN AGAIN THU NIGHT INTO EARLY FRI MORNING. SOUTHERLY SWELL COUPLED WITH THE GAP WIND GENERATED SWELL WILL BUILD SEAS TO 8-9 FT. GULF OF PAPAGAYO...PULSING WINDS OF 20-25 KT AND SEAS TO 8 FT ARE EXPECTED OVERNIGHT TONIGHT INTO EARLY THU MORNING WITH THE BENEFIT OF NOCTURNAL DRAINAGE FLOW. WINDS AND SEAS WILL DIMINISH AFTER SUNRISE THU. $$ GR