000 AXPZ20 KNHC 150921 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...SPECIAL FEATURES... A BROAD AREA OF LOW PRESSURE IS LOCATED NEAR 15N111W WITH A CENTRAL PRESSURE ESTIMATED AT 1006 MB. SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THIS SYSTEM HAVE BECOME BETTER ORGANIZED OVERNIGHT. CURRENTLY...SCATTERED MODERATE TO STRONG CONVECTION IS FROM 15N-19N BETWEEN 110W-115W...AND WITHIN 120 NM OF LINE FROM 8N111W TO 15N107W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM 10N-14N BETWEEN 105W-107W. A RECENT SCATTEROMETER PASS INDICATES THAT THIS SYSTEM DOES NOT HAVE YET A CLOSED SURFACE CIRCULATION. ENVIRONMENTAL CONDITIONS REMAIN 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 WITHIN 48 HOURS. BASED ON THE HIGH PROBABILITY OF GENESIS...A GALE WARNING HAS BEEN ISSUED IN 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... TROPICAL WAVE OVER THE YUCATAN AND S MEXICO EXTENDS S INTO THE EPAC WATERS ALONG 91W TO 9N MOVING W-NW NEAR 15 KT. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS WITHIN 120 NM ALONG COAST OF MEXICO BETWEEN 89W-94W. THE WEAK TROPICAL WAVE THAT WAS ALONG 128W IS NO LONGER DISCERNIBLE AND WAS DROPPED FROM THE 15/0600 UTC ANALYSIS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 7N78W ALONG 7N82W 9N90W 9N97W TO 12N102W THEN RESUMES NEAR 12N113W ALONG 7N124W TO 8N132W WHERE THE ITCZ AXIS CONTINUES TO 9N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS N OF 3N E OF 80W... INCLUDING GULF OF PANAMA. CLUSTERS OF SCATTERED MODERATE ISOLATED STRONG CONVECTION ARE WITHIN 300 NM S OF MONSOON TROUGH BETWEEN 91W-102W...WITHIN 200 NM S OF MONSOON TROUGH BETWEEN 112W-130W...AND WITHIN 200 NM N OF MONSOON TROUGH/ITCZ BETWEEN 130W-140W. ...DISCUSSION... A 1033 MB HIGH PRES LOCATED WELL NW OF AREA NEAR 42N148W EXTENDS A SURFACE RIDGE SE ACROSS THE FORECAST WATERS ALONG 32N133W TO NEAR 24N120W. MODERATE TO LOCALLY FRESH TRADE WINDS ARE NOTED ALONG THE SOUTHERN PERIPHERY OF THE RIDGE MAINLY FROM 14N TO 19N 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 THROUGH SAT. A SURFACE TROUGH IS INLAND OVER THE W COAST OF MEXICO GENERATING SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 90 NM ALONG THE COAST BETWEEN 20N-23N. 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 BOUNDED BY LINE FROM 00N 108W ALONG 15N104W TO 15N108W TO 7N116W TO 00N132W. GAP WINDS... GULF OF PAPAGAYO...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. $$ PAW