000 AXPZ20 KNHC 160317 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE FEB 16 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 0315 UTC. ...SPECIAL FEATURE... GULF OF TEHUANTEPEC GALE WARNING...A 20-30 KT NORTHERLY SURGE WILL BEGIN LATE TONIGHT AND THEN GRADUALLY INCREASE THROUGHOUT THE DAY ON TUE REACHING MINIMAL GALE STRENGTH AROUND SUNSET ON TUE. THE GALE WILL BRIEFLY STRENGTHEN TO 30-40 KT LATE WED NIGHT INTO EARLY THU...WITH GALE CONDITIONS PERSISTING THROUGH SUNRISE ON SAT. EXPECT SEAS TO BUILD TO ABOUT 15 FT NEAR 15N95.5W ON WED NIGHT. ...INTERTROPICAL CONVERGENCE ZONE... A SURFACE TROUGH IS ANALYZED FROM 03N135W TO 12N130W WITH ISOLATED MODERATE TO STRONG CONVECTION OBSERVED WITHIN 180 NM E OF THE TROUGH. STRONG NE WINDS ARE OBSERVED WITHIN 180 NM OF 10N134W LATE TUE...WITH THE WINDS DIMINISHING TO 20 KT OR LESS EARLY WED. SCATTEROMETER WINDS INDICATE THAT THE ITCZ FORMS NEAR 05N87W AND EXTENDS WESTWARD TO 06N132W WHERE THE LOW LEVEL FLOW IS INTERRUPTED BY THE PREVIOUSLY DESCRIBED SURFACE TROUGH...THEN RESUMES FROM 04N135W TO BEYOND 01N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED ALONG THE ITCZ WITHIN 120 NM EITHER SIDE OF A LINE FROM 05N94W TO 03N117W TO 07N128W AND ALSO WITHIN 30 NM OF LINE FROM 03N137W TO 01N140W. ...DISCUSSION... ELSEWHERE N OF 15N E OF 120W...A SURFACE RIDGE EXTENDS SE FROM 25N120W TO BEYOND 15N102W. THE PRESSURE GRADIENT IS RELAXING WITH GENTLE NORTHERLY WINDS EXPECTED ACROSS THE OPEN PACIFIC WATERS BETWEEN 110-120W THE REMAINDER OF TONIGHT INTO TUE. A WEAK SURFACE HIGH WILL DEVELOP ALONG THE RIDGE NEAR 22N110W LATE TUE WITH LIGHT AND VARIABLE WINDS EXPECTED W OF 107W THROUGH WED. BY THEN A SECOND SURFACE HIGH WILL SHIFT E INTO THE AREA NEAR 27N120W...AND THEN SHIFT NE TO OVER NW MEXICO ON WED NIGHT WITH A WEAK COLD FRONT OR TROUGH PASSES E ACROSS THE WATERS N OF 24N ON WED NIGHT THROUGH THU NIGHT. A STATIONARY RIDGE WILL SET UP IN THE WAKE OF THE FRONT FROM 27N120W TO 15N104W ON THU NIGHT AND MEANDER THROUGH THE WEEKEND. COMBINED SEAS OF 4-7 FT CURRENTLY ACROSS THE PACIFIC WATERS BETWEEN 107-120W WILL CONTINUE TO SUBSIDE WITH 3-6 FT CONDITIONS EXPECTED ON TUE AND WED. POST-FRONTAL NW SWELL IN THE FORM OF 6-9 FT SEAS WILL ARRIVE AT 30N120W LATE THU NIGHT...REACH THE PACIFIC COAST OF THE NORTHERN BAJA PENINSULA ON FRI AND THE SOUTHERN COAST OF BAJA ON SAT. FRESH TO LOCALLY STRONG NW WINDS ARE EXPECTED ACROSS THE CENTRAL GULF OF CALIFORNIA WATERS TONIGHT...THEN THE NW FLOW WILL DIMINISH TO GENTLE BY TUE NIGHT...AND BECOME LIGHT AND VARIABLE ON WED NIGHT. S OF 15N E OF 110W...MODERATE E TO SE WINDS DOMINATE THE AREA W OF 92W WITH COMBINED SEAS OF 7-10 FT IN SUBSIDING NE...S AND NW SWELL. THESE SEAS SHOULD SUBSIDE TO LESS THAN 8 FT BY WED MORNING. STRONG TO NEAR GALE FORCE NE PULSES ARE EXPECTED EACH NIGHT ACROSS AND DOWNSTREAM OF THE GULF OF PAPAGAYO. ANOTHER GALE WILL DEVELOP IN THE GULF OF TEHUANTEPEC LATE TUE...WITH THE GALE CONDITIONS SPREADING S INTO THE AREA N OF 13N BETWEEN 94- 97W ON WED...WITH THE ASSOCIATED TONGUE OF STRONG TO NEAR GALE WINDS SPREADING S TO NEAR 10N100W ON THU. SEAS FROM BOTH GAP EVENTS WILL MERGE AGAIN WITH 7-11 FT SEAS ACROSS THE AREA W OF 93W LATE IN THE WEEK. PULSES OF FRESH NORTHERLY WINDS WILL SPREAD S FROM THE GULF OF PANAMA TO ALONG ABOUT 04N TONIGHT AND TUE NIGHT WITH GUIDANCE SUGGESTING STRONG N-NE WINDS WILL RESUME ON WED NIGHT...WITH ASSOCIATED SEAS BUILDING TO ABOUT 10 FT NEAR 05N82W. ELSEWHERE FROM THE EQUATOR TO 32N E OF 140W...A MID TO UPPER LEVEL CYCLONE AT 18N140W HAS AN ASSOCIATED SURFACE INVERTED TROUGH EXTENDING FROM 13N140W TO 21N138W...WITH THE ENTIRE SYSTEM EXPECTED TO MOVE W OF 140W IN THE NEXT FEW HOURS. SCATTERED MODERATE CONVECTION IS ENHANCED E OF THE TROUGH WITHIN 210 NM OF LINE FROM 11N136W TO 22N130W. ALTHOUGH ASSOCIATED WINDS HAVE DIMINISHED TO 20 KT OR LESS...COMBINED SEAS OF 6-9 FT IN MIXED E AND NW SWELL CONTINUE ACROSS THE WATERS N OF 15N W OF 135W. EXPECT A W-E ORIENTATED RIDGE FROM 25N140W TO 26N120W ON TUE NIGHT WITH A TROUGH...OR WEAK COLD FRONT...RAPIDLY SWEEPING E ACROSS THE WATERS N OF THE RIDGE ACCOMPANIED BY STRONG NW FLOW N OF 30N W OF THE FRONT LATE TUE NIGHT INTO WED. ANOTHER ROUND OF LARGE NW SWELL IN THE FORM OF 8-13 FT SEAS WILL PROPAGATE E ACROSS THE WATERS N OF 22N ON WED-FRI. STRONG SW FLOW WILL DEVELOP ACROSS THE FAR NW PORTION ON SAT IN ADVANCE OF ANOTHER COLD FRONT. MIXING SWELL RESULTING IN 8 TO 11 FT COMBINED SEAS ACROSS THE TROPICS WILL GRADUALLY SUBSIDE THROUGH MID WEEK. $$ NELSON