000 AXPZ20 KNHC 200924 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT JUN 20 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. ...TROPICAL WAVES... A TROPICAL WAVE AXIS IS ALONG 88W/89W N OF 09N TO ACROSS EL SALVADOR AND WESTERN HONDURAS MOVING W AT 10-15 KT. ONLY ISOLATED SHOWERS ARE ASSOCIATED WITH THE WAVE. A TROPICAL WAVE AXIS IS ALONG 102W FROM 05N-14N MOVING W AT 10- 15 KT. SCATTERED MODERATE CONVECTION IS ON EITHER SIDE OF THE WAVE AXIS. A CLUSTER OF MODERATE TO STRONG CONVECTION HAS DEVELOPED TO THE E OF THE WAVE AXIS AND COVERS THE AREA FROM 10N- 13N BETWEEN 95W AND 99W. THIS CONVECTION REMAINS UNDER FAVORABLE DIFFLUENCE ALOFT. A RECENT SCATTEROMETER PASS SHOWED VERY WELL THE WIND SHIFT ASSOCIATED THIS WAVE. A TROPICAL WAVE EXTENDS FROM 12N124W TO 05N125W MOVING W NEAR 15 KT. SCATTERED SHOWERS ARE NOTED NEAR THE WAVE AXIS. ANOTHER TROPICAL WAVE IS ANALYZED FROM 16N136W TO 07N137W. FEW SHOWERS ARE NOTED NEAR 09N137W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 07N78W TO 08N85W TO 07N100W. THE ITCZ BEGINS AT 07N104W...AND CONTINUES TO 09N116W TO 08N122W TO 06N130W TO 03N140W. A CLUSTER OF MODERATE TO STRONG CONVECTION IS ALONG THE COAST OF COLOMBIA FROM 05N TO THE TROUGH AXIS. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS N OF 06N BETWEEN 81W AND 84W AND FROM 03N TO 05N BETWEEN 85W AND 89W. SIMILAR CONVECTION CAN BE FOUND S OF 05N W OF 135W. ...DISCUSSION... UPPER LEVELS...A LARGE ANTICYCLONE CENTERED NEAR 26N127W CONTINUES TO DOMINATES THE N PART OF THE AREA MAINLY N OF 20N W OF 120W. ANOTHER ANTICYCLONE IS FARTHER S NEAR 13N121W. AN UPPER- LEVEL-TROUGH EXTENDS ACROSS NW MEXICO AND SOUTHERN BAJA CALIFORNIA INTO THE EPAC TO NEAR 20N112W. MODERATE TO STRONG SUBSIDENCE AND IMPLIED DRY AIR MASS IS OBSERVED ON WATER VAPOR IMAGERY ACROSS MUCH OF THE FORECAST REGION N OF 18N. NORTHERLY FLOW IS OVER SE MEXICO...THE GULF OF TEHUANTEPEC AND THE REMAINDER OF THE AREA N OF 10N BETWEEN 90W AND 100W DUE TO THE PRESENCE OF AN ANTICYCLONE OVER MEXICO NEAR 20N103W AND A BROAD UPPER LOW SITUATED OVER THE SE GULF OF MEXICO. A RIDGE IS NOTED OVER PANAMA AND COSTA RICA AND THE FAR EASTERN PACIFIC. AT THE SURFACE...HIGH PRES LOCATED WELL N OF AREA EXTENDS A RIDGE ACROSS THE FORECAST WATERS TO NEAR THE REVILLAGIGEDO ISLANDS. THE PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES IN THE VICINITY OF THE ITCZ IS MAINTAINING MODERATE TO LOCALLY FRESH NE-E TRADES OVER THE WESTERN WATERS N OF THE ITCZ FROM 10N- 16N W OF 132W. SCATTEROMETER DATA CONFIRMED THE PRESENCE OF THESE WINDS. SEAS OF 8-9 FT ARE NOTED WITHIN THE AREA OF THE TRADES PER A COUPLE OF ALTIMETER PASSES. THE HIGH PRES IS FORECAST TO WEAKEN OVER THE 24 HRS AS A WEAK COLD FRONT APPROACHES THE FAR NW CORNER OF THE AREA. A NEW HIGH PRES CELL IS FORECAST TO DEVELOP AHEAD OF THE FRONT OVER THE NW WATERS TONIGHT. SE SWELLS MIXED WITH LONG PERIOD CROSS-EQUATORIAL SW SWELLS ARE PRODUCING AN AREA OF 8-9 FT SEAS S OF 02N BETWEEN 118W AND 134W AND S OF 02S BETWEEN 112W AND 118W. SEAS ARE FORECAST TO SUBSIDE TO LESS THAN 8 FT ACROSS THIS GENERAL AREA IN ABOUT 48 HOURS. GAP WINDS... GULF OF PAPAGAYO...PULSING WINDS OF 20-25 KT ARE EXPECTED ACROSS THIS GULF DURING THE OVERNIGHT AND EARLY MORNING HOURS WITH THE ASSISTANCE OF THE NOCTURNAL DRAINAGE FLOW AND SOME ADDED ENHANCEMENT FROM THE EASTERLY GRADIENT FLOW ACROSS THE SW CARIBBEAN. SEAS ARE FORECAST TO BUILD TO 9 FT. THE RESULTANT ENE SWELLS WILL PROPAGATE W REACHING 93W BY EARLY SAT AFTERNOON AND 97W BY SAT NIGHT. THIS WEATHER PATTERN IS FORECAST TO PERSIST OVER THE NEXT 48 HOURS. GULF OF TEHUANTEPEC...THE COMBINATION OF A TROUGH OVER THE SW GULF AS WELL AS THE PASSAGE OF A TROPICAL WAVE ACROSS THE FAR EASTERN PACIFIC HAS HELPED GENERATE FRESH TO LOCALLY STRONG GAP WINDS OVER THE GULF OF TEHUANTEPEC. THE TROPICAL WAVE IS NOW MOVING WESTWARD AND AWAY FROM THE TEHUANTEPEC AREA HELPING WINDS TO FALL TO 20 KT OR LESS. WINDS WILL ONCE AGAIN STRENGTHEN LATE SUNDAY NIGHT INTO MON AS A ANOTHER TROPICAL WAVE PROPAGATING THROUGH THE FAR EPAC WILL HELP TO GENERATE ANOTHER ROUND OF NORTHERLY GAP WINDS. $$ GR