000 AXPZ20 KNHC 182156 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC MON APR 18 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 2145 UTC. ...INTERTROPICAL CONVERGENCE ZONE... A 1007 MB SURFACE LOW OVER NW COLOMBIA NEAR 08N74W TRAILS A SURFACE TROUGH SW ALONG 05.5N77W TO 05.5N84W. A FEW SHOWERS ARE NOTED ALONG THE TROUGH. SCATTEROMETER WINDS INDICATE AN ITCZ FORMS AT 06N85W AND WIGGLES W TO 06N106W...THEN TURNS NW TO 09N114W...THEN SW THROUGH AN EMBEDDED 1007 MB LOW PRESSURE AT 06N130W WITH THE ITCZ THEN CONTINUING SW TO BEYOND 03N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED ALONG THE ITCZ WITHIN 120 NM OF 06N96W AND WITHIN 90 NM OF LINE FROM 07N111W TO 11N114W. SIMILAR CONVECTION IS OBSERVED WITHIN 90 NM OF THE LOW. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 60 NM OF 06N135W. ...DISCUSSION... N OF 15N E OF 120W... A WEAK SURFACE RIDGE EXTENDS FROM NEAR 23N120W TO BEYOND 15N107W. A SURFACE WILL DEVELOP INTERMITTENTLY ALONG THE RIDGE NEAR 23N OVER THE NEXT DAY OR SO. A WEAK TROUGH WILL SWEEP E ACROSS THE WATERS N OF THE RIDGE ON WED AND THU AND BECOME STATIONARY OVER THE NORTHERN BAJA PENINSULA ON FRI WITH THE GRADIENT SUPPORTING STRONG SOUTHERLY FLOW N OF 29.5N AND 30N ON FRI. GUIDANCE SUGGESTS THE NEXT STRONG GULF OF TEHUANTEPEC WIND EVENT WILL OCCUR ON FRI NIGHT. S OF 15N E OF 110W... NOCTURNAL PULSES OF STRONG ENE WINDS ARE EXPECTED ACROSS...AND JUST DOWNSTREAM OF THE GULF OF PAPAGAYO LATE TONIGHT...AND AGAIN LATE WED NIGHT. ONLY FRESH DRAINAGE FLOW FORECAST ACROSS THE GULF OF PAPAGAYO ON TUE NIGHT. FRESH N WINDS EXPECTED ACROSS AND DOWNSTREAM OF THE GULF OF PANAMA EACH NIGHT THROUGH WED NIGHT. LONG PERIOD CROSS-EQUATORIAL SOUTHERLY SWELL IN THE FORM OF 7-8 FT SEAS WILL SPREAD N ACROSS THE EQUATOR BETWEEN 100-110W LATE WED THROUGH LATE THU. ELSEWHERE FROM THE EQUATOR TO 32N E OF 140W... A COLD FRONT EXTENDS FROM 32N130W TO 21N140W WITH STRONG SOUTHERLY WINDS EXPECTED TO PERSIST TO THE N OF 29.N WITHIN 60 NM E OF FRONT EARLY TONIGHT RESULTING IN COMBINED SEAS TO 7-10 FT. STRONG WESTERLY WINDS ARE NOTED FROM 29-32N W OF 133W WITH LARGE NW SWELL DRIVING SEAS HEIGHTS UP TO 16 FT. THESE POST- FRONTAL WINDS WILL DIMINISH TO 20 KT OR LESS ON TUE. ENHANCED SEAS OF 8 FT OR GREATER WILL SPREAD S ACROSS THE WATERS N OF 19N ON TUE AND SUBSIDE BELOW 8 FT ON WED. A SECONDARY COLD FRONT IS ALREADY EVIDENT...BUT IS EXPECTED TO BE ACCOMPANIED BY ONLY A 10- 15 KT WIND SHIFT. ALTHOUGH NE TRADES ARE EXPECTED TO REMAIN IN THE 15-20 KT RANGE ACROSS THE TROPICS...EXPECT COMBINED SEAS TO BUILD TO 7-8 FT WITHIN 150 NM NW OF A LINE FROM 13N123W TO 11N130W TONIGHT...AND EXPAND N TO WITHIN 360 NM NW OF A LINE FROM 11N123W TO 08N124W ON TUE BEFORE BEGINNING TO SUBSIDE. $$ NELSON