000 AXPZ20 KNHC 301546 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC THU APR 30 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1545 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS SW FROM 12N101W TO 07N130W WHERE SCATTEROMETER WINDS INDICATE THAT THE ITCZ FORMS...THEN CONTINUES SW TO BEYOND 06N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED ALONG THE MONSOON TROUGH AND ITCZ WITHIN 240 NM EITHER SIDE OF A LINE FROM 10N112W TO 06N130W TO 08N140W. .LOW PRES 1009 MB IS OBSERVED OVER THE GULF OF PANAMA AT 08N80W WITH A TROUGH EXTENDING S TO 02.5N83W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED E OF THE TROUGH ALONG THE COAST OF COLOMBIA WITHIN 90 NM OF 03.5N80W...AND A FEW TSTMS ARE NOW DEVELOPING NEAR THE BASE OF THE TROUGH. .SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 150 NM EITHER SIDE OF A LINE FROM 10N86W TO 00N91W...AND ALSO WITHIN 60 NM OF COAST OF CENTRAL AMERICA FROM 87W TO 93W. ISOLATED MODERATE CONVECTION IS FLARING ELSEWHERE BETWEEN 83- 103W. ...DISCUSSION... A SERIES OF UPPER SHORT WAVE TROUGHS ARE PASSING EASTWARD ACROSS THE NORTHERN PORTION OF THE DISCUSSION AREA. THE EASTERNMOST TROUGH IS CURRENTLY OVER NORTHERN MEXICO. A SECOND TROUGH HAS ITS MEAN AXIS CURRENTLY TILTED NEGATIVELY FROM 32N125W TO 24N120W. THE WESTERNMOST TROUGH EXTENDS FROM 32N131W TO 25N140W. SOME UPPER MOISTURE IS NOTED NEAR EACH OF THESE TROUGHS... OTHERWISE THE UPPER LEVELS APPEAR DRY N OF 13N W OF 102W IN NEARLY ZONAL FLOW. AT THE SURFACE...A BROAD RIDGE EXTENDS SE FROM 32N138W TO 16N120W. A BAND OF N-NE 20-25 KT LOW LEVEL FLOW IS OBSERVED WITHIN 150 NM OF A LINE FROM 30N128W TO 25N140W WITH SEAS OF 9- 10 FT. NW SWELL IS MIXING WITH S SWELL RESULTING IN COMBINED SEAS TO 0F 7-9 FT ELSEWHERE W OF LINE FROM 30N118W TO 20N140W. THE WINDS WILL DIMINISH TO 20 KT OR LESS LATER TODAY AND THE SEAS WILL GRADUALLY SUBSIDE. A COLD FRONT WILL DIP INTO THE AREA N OF 29N ALONG 125W ON FRI NIGHT WITH 20 KT N WINDS SPREADING S ACROSS THE DISCUSSION AREA N OF 28N W OF 125W. COMBINED SEAS OF 7-10 FT WILL BUILD BRIEFLY BEHIND THE FRONT ON SAT ACROSS THE WATERS N OF 26N W OF 130W...THEN SUBSIDE ON SUN. GULF OF TEHUANTEPEC...THE NORTHERLY FLOW DIMINISHED BELOW GALE FORCE THIS MORNING AND IS EXPECTED TO GRADUALLY DIMINISH TO LESS THAN 20 KT ON FRI AFTERNOON. LARGE LONG PERIOD SW SWELL GENERATED FROM A VERY LARGE STORM SYSTEM ACROSS THE SE PACIFIC WILL MOVE N-NE INTO REGIONAL WATERS TODAY AND REACH THE CENTRAL AMERICAN AND MEXICAN COAST SAT... PRODUCING VERY LARGE AND DANGEROUS WAVES IN THE COASTAL ZONES FROM PANAMA TO BAJA CALIFORNIA. $$ NELSON