000 AXPZ20 KNHC 150235 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SAT AUG 15 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. ...SPECIAL FEATURES... A BROAD AREA OF LOW PRESSURE IS LOCATED NEAR 15N110W WITH A CENTRAL PRESSURE ESTIMATED AT 1006 MB. SHOWERS AND TSTMS ASSOCIATED WITH THIS SYSTEM HAVE CHANGE LITTLE IN ORGANIZATION DURING THE DAY. CURRENTLY...SCATTERED MODERATE TO STRONG CONVECTION IS NOTED WITHIN 150 NM NW SEMICIRCLE OF CENTER. A BAND OF MODERATE TO ISOLATED STRONG CONVECTION IS NOTED WITHIN AROUND 180 NM OF A LINE FROM 17N105W TO 13N110W TO 11N115W. A RECENT SCATTEROMETER PASS INDICATES THAT THIS SYSTEM DOES NOT HAVE YET A CLOSED SURFACE CIRCULATION. ENVIRONMENTAL CONDITIONS ARE CONDUCIVE FOR A TROPICAL DEPRESSION TO FORM FROM THIS SYSTEM ON SAT OR SUN AS IT TRACKS W-NW AT AROUND 10 KT. THIS LOW HAS A HIGH PROBABILITY OF BECOMING A TROPICAL CYCLONE IN ABOUT 24-36 HOURS. BASED ON THE HIGH PROBABILITY OF GENESIS...A GALE WARNING HAS BEEN ISSUED FOR THE HIGH SEAS FORECAST BEGINNING SAT EVENING AND CONTINUING INTO SUN. THE GALE WARNING MAY BE TRANSITIONED TO TROPICAL CYCLONE WARNING. PLEASE REFER TO THE HIGH SEAS FORECAST ISSUED UNDER AWIPS/WMO HEADERS MIAHSFEP2/ FZPN03 KNHC. ...TROPICAL WAVES... A TROPICAL WAVE OVER NORTHERN CENTRAL AMERICA EXTENDS S INTO THE EPAC WATERS TO NEAR 08N89W. A FEW SHOWERS ARE NEAR THE SOUTHERN END OF THE WAVE AXIS. A WEAK TROPICAL WAVE IS ALONG 128W FROM 09N-17N MOVING W NEAR 10 KT. NO SIGNIFICANT DEEP CONVECTION IS ASSOCIATED WITH THIS WAVE. A TROPICAL WAVE IS ANALYZED ALONG 140W/141W FROM 09N-16N MOVING W 10 KT. SCATTERED SHOWERS ARE ON EITHER SIDE OF THE WAVE AXIS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 07N78W TO 07N90W TO 12N102W THEN RESUMES NEAR 12N114W TO 07N125W TO 08N132W. THE ITCZ AXIS STRETCHES FROM 08N132W TO 09N140W. SCATTERED MODERATE CONVECTION IS NOTED FROM 04N TO 07N E OF 78W TO THE COAST OF COLOMBIA. SCATTERED MODERATE ISOLATED STRONG CONVECTION CAN BE FOUND FROM 05N TO 12N BETWEEN 95W AND 99W. SCATTERED MODERATE CONVECTION IS WITHIN 150-180 NM OF TROUGH BETWEEN WITHIN 120W AND 132W. ...DISCUSSION... A 1033 MB HIGH PRES LOCATED WELL NW OF AREA NEAR 42N148W EXTENDS A RIDGE SE ACROSS THE FORECAST WATERS TO NEAR 20N110W. MODERATE TO LOCALLY FRESH TRADE WINDS ARE NOTED ALONG THE SOUTHERN PERIPHERY OF THE RIDGE MAINLY FROM 14N TO 22N W OF 130W. IN ADDITION...THE PRES GRADIENT BETWEEN THE RIDGE AND A TROUGH ACROSS THE BAJA CALIFORNIA PENINSULA IS PRODUCING MODERATE TO FRESH WINDS OVER THE NE WATERS. THESE WINDS WILL PERSIST OVER THE NEXT 24 HOURS. THE LOW PRES PREVIOUSLY LOCATED NEAR 20N140W HAS MOVED W OF AREA AND OPENED UP INTO A WELL DEFINED TROUGH BASED ON SCATTEROMETER DATA. WINDS AND SEAS IN ASSOCIATION WITH THIS SYSTEM HAVE DIMINISHED BELOW THE ADVISORY CRITERIA ACROSS THE FORECAST AREA. CROSS-EQUATORIAL S-SE SWELL ACROSS THE S/CENTRAL PORTION OF THE FORECAST REGION WILL GRADUALLY SUBSIDE THROUGH EARLY SAT MORNING. SEAS TO 8 FT CAN CURRENTLY BE FOUND ACROSS THE AREA E OF LINE FROM 10N111W TO 00N128W TO ANOTHER LINE FROM 10N105W TO 00N116W TO 03.4S112W. GAP WINDS... GULF OF TEHUANTEPEC...PULSING NORTHERLY WINDS OF 20 KT ARE EXPECTED OVERNIGHT TONIGHT INTO SAT MORNING WITH SEAS OF 6-7 FT. GULF OF PAPAGAYO...PULSING NE-E WINDS OF 20 KT ARE ALSO EXPECTED ACROSS THIS GULF DURING THE OVERNIGHT AND EARLY MORNING HOURS WITH THE ASSISTANCE OF THE NOCTURNAL DRAINAGE FLOW. SEAS OF 6-7 FT WILL PROPAGATE WESTWARD AND DOWNSTREAM OF THE GULF REACHING 90W/91W. $$ GR