000 AXPZ20 KNHC 122159 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2100 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 98W FROM 10N TO 16N MOVING W ABOUT 15 KT. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS AHEAD OF THE WAVE AXIS FROM 11N TO 16N BETWEEN 98W AND 104W. SCATTERED MODERATE CONVECTION IS ALSO NOTED BEHIND THE WAVE AXIS FROM 10N TO 13N BETWEEN 96W AND 98W. AN EASTERLY WIND SURGE IN THE 20-25 KT RANGE IS SEEN PER SCATTEROMETER DATA EAST OF THE WAVE AXIS AND MAINLY FROM 11N TO 14N TO 91W. 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 BY LATER THIS WEEK...AND A TROPICAL CYCLONE WILL LIKELY FORM LATE THIS WEEKEND OR EARLY NEXT WEEK WHILE IT MOVES W-NW AT 10- 15 KT. A TROPICAL WAVE EXTENDS FROM 16N117W TO 08N118W 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 15N130W TO 08N132W MOVING W AROUND 10-15 KT. SCATTERED MODERATE CONVECTION IS ON EITHER SIDE OF THE WAVE AXIS FROM 08N TO 13N BETWEEN 130W AND 135W. A CLUSTER OF MODERATE TO ISOLATED STRONG CONVECTION IS WHERE THE WAVE MEETS THE ITCZ AXIS COVERING THE AREA FROM 07N TO 09N BETWEEN 113W AND 135W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH AXIS EXTENDS FROM 06N77W TO 08N95W TO 11N96W TO 09N102W 12N110W TO 11N115W. ITCZ AXIS STRETCHES FROM 07N119W TO 11N131W TO 09N140W. SCATTERED MODERATE CONVECTION IS OBSERVED FROM 05N TO 07N BETWEEN 84W AND 87W...FROM 10N TO 12N BETWEEN 88W AND 95W...AND FROM 06N TO 09N BETWEEN 104W AND 109W. SCATTERED MODERATE ISOLATED STRONG CONVECTION CAN BE FOUND FROM 05N TO 09N BETWEEN 132W AND 137W. ...DISCUSSION... A 1009 MB LOW PRES IS LOCATED NEAR 18N134W MOVING W AT 10 KT. VISIBLE SATELLITE IMAGES CONTINUE TO SHOW A WELL-DEFINED EXPOSED LOW-LEVEL CENTER ON THE WESTERN SIDE OF THE DEEP CONVECTION. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 75NM SE AND 45 NM NW QUADRANTS. DEVELOPMENT OF THIS SYSTEM IS UNLIKELY DUE TO UNFAVORABLE ENVIRONMENTAL CONDITIONS WHILE IT MOVES WESTWARD AT ABOUT 10 KT. THIS SYSTEM COULD OPEN UP INTO A TROUGH BY LATE THU. A SURFACE RIDGE DOMINATES THE N WATERS ANCHORED ON A 1019 MB HIGH PRES LOCATED NEAR 28N128W. THE PRESSURE GRADIENT BETWEEN THIS RIDGE AND THE AFOREMENTIONED LOW PRES IS PRODUCING AN AREA OF MODERATE TO FRESH WINDS FROM 16N TO 21N BETWEEN 128W AND 132W BASED ON SCATTEROMETER DATA. THESE WINDS ARE FORECAST TO PERSIST AND MOVE IN TANDEM WITH THE LOW PRES OVER THE NEXT COUPLE OF DAYS. CROSS-EQUATORIAL S-SW SWELL CONTINUES TO PROPAGATE ACROSS MUCH OF THE AREA WILL GRADUALLY SUBSIDE THROUGH LATE FRI. COMBINED SEAS IN THE 8-9 FT RANGE CAN BE FOUND ACROSS MUCH OF THE AREA S OF 07N BETWEEN 81W AND 92W...EXCEPT IN THE LEE OF THE GALAPAGOS ISLANDS...AND W OF 92W AND S OF A LINE FROM 10N92W TO 07N110W TO 03N120W TO 03N140W GAP WINDS... GULF OF TEHUANTEPEC...THE PRESSURE GRADIENT BETWEEN A SURFACE RIDGE ACROSS THE GULF OF MEXICO AND A TROPICAL WAVE CURRENTLY LOCATED ALONG 98W HAS ALLOWED NLY WINDS TO FUNNEL THROUGH CHIVELA PASS. A FRESH TO STRONG N-NE WINDS SHOULD CONTINUE HERE THROUGH THU MORNING WITH THE ASSISTANCE OF NOCTURNAL DRAINAGE FLOW. SOUTHERLY SWELL COUPLED WITH THE GAP WIND GENERATED SWELL WILL BUILD SEAS TO 8-9 FT. THIS GAP WIND EVENT WILL PERSIST ON FRI. GULF OF PAPAGAYO...PULSING WINDS OF 20-25 KT ARE EXPECTED OVERNIGHT TONIGHT INTO EARLY THU MORNING WITH THE BENEFIT OF NOCTURNAL DRAINAGE FLOW. SEAS TO 9 FT HERE IN COMBINED NE WIND WAVES AND S SWELL...WILL SPREAD W BEHIND THE ABOVE MENTIONED TROPICAL WAVE. WINDS AND SEAS WILL DIMINISH AFTER SUNRISE THU. $$ GR