000 AXPZ20 KNHC 150333 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN FEB 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0300 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC...THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE OVER THE NORTHERN GULF OF MEXICO...AND LOWER PRESSURE FARTHER SOUTH ALONG THE ITCZ...IS ALLOWING STRONG NORTHERLY WINDS TO BLOW THROUGH THE CHIVELA PASS...DELIVERING WINDS TO GALE FORCE THROUGH THE GULF OF TEHUANTEPEC. THIS PATTERN IS EXPECTED TO PERSIST THROUGH SUNDAY MORNING...WITH THE STRONGEST WINDS OF 30-40 KT OCCURRING DURING THE OVERNIGHT HOURS DUE TO LOCAL DRAINAGE FLOW. WINDS AND SEAS WILL GRADUALLY DIMINISH SUNDAY THROUGH MONDAY...AS THE HIGH PRESSURE THAT IS TO THE NORTH OF THE AREA WEAKENS AND SHIFTS EASTWARD. LOOKING AHEAD... GLOBAL MODELS SUGGEST ANOTHER ROUND OF GALE FORCE WINDS IN THE GULF OF TEHUANTEPEC BY WEDNESDAY. WINDS MAY REACH 40-45 KT BY WED EVENING. GULF OF PAPAGAYO...THE PRESSURE GRADIENT OVER SOUTHERN MEXICO AND CENTRAL AMERICA WILL REMAIN STRONG ENOUGH TO SUPPORT GALE FORCE WINDS ACROSS THE GULF OF PAPAGAYO OVERNIGHT TONIGHT AND EARLY SUN MORNING WITH THE AID OF THE NOCTURNAL DRAINAGE FLOW. THE RELAXING GRADIENT WILL ALLOW WINDS TO DIMINISH SOMEWHAT THROUGH LATE SUNDAY. NE WINDS OF 20-30 KT AND SEAS OF 8-10 FT ARE EXPECTED SUN NIGHT INTO EARLY MONDAY MORNING. WINDS AND SEAS WILL FURTHER DIMINISH LATE MON INTO TUE. THE COMBINED EFFECTS OF THE TEHUANTEPEC AND PAPAGAYO GAP WIND EVENTS WILL CREATE MERGING NORTHEASTERLY SWELL WITH SEAS OF 8 FT OR GREATER OVER AN AREA FROM 03N TO 13N BETWEEN 90W AND 110W BY LATE SUNDAY. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE ITCZ EXTENDS FROM 02N85W TO 06N106W TO 09N115W TO 09N130W TO BEYOND 06N140W. NO SIGNIFICANT CONVECTION. ...DISCUSSION... ALOFT...A CUT-OFF LOW IS SPINNING NEAR 27N115W GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS OVER PARTS OF BAJA CALIFORNIA AND ALONG THE WEST COAST OF MEXICO MAINLY NEAR LOS MOCHIS. AN UPPER-LEVEL TROUGH EXTENDS FROM THE LOW CENTER TO 20N113W TO 15N115W. A DIFFLUENT PATTERN ALOFT BETWEEN THIS TROUGH AN A RIDGE OVER MEXICO IS HELPING TO INDUCE SOME CONVECTIVE ACTIVITY OVER SW MEXICO...PARTICULARLY FROM MICHOACAN TO JALISCO. THE CUT-OFF LOW IS FORECAST TO REMAIN NEARLY STATIONARY OVER THE NEXT 18-24 HOURS...THEN WILL MOVE ACROSS NORTHERN BAJA CALIFORNIA INTO NW MEXICO ON MON. A TONGUE OF MOISTURE IS FORECAST TO PERSIST ALONG THE WEST COAST OF MEXICO ROUGHLY FROM WESTERN GUERRERO TO NAYARIT THROUGH MON. A 75 NM WIDE BAND OF SHOWERS WITH EMBEDDED TSTMS IS NOTED FROM 11N105W TO 15N103W. THIS CONVECTIVE ACTIVITY IS BEING ENHANCED BY DIVERGENCE ALOFT ASSOCIATED WITH THE ABOVE MENTIONED UPPER- LEVEL TROUGH. THE FRESH TO STRONG E-SE WINDS PREVIOUSLY SEEN IN THE SAME AREA HAVE DIMINISHED TO 15-20 KT BASED ON A RECENT RAPIDSCAT. HIGH PRES LOCATED WELL N OF AREA EXTENDS A RIDGE ACROSS THE N WATERS...ESPECIALLY N OF 20N W OF 115W. PRES GRADIENT BETWEEN THE RIDGE AND AN APPROACHING COLD FRONT IS RESULTING IN SOME INCREASE IN WINDS ACROSS THE FAR NW CORNER. THE MOST RECENT ASCAT PASS SHOWED AN AREA OF FRESH TO STRONG SOUTHERLY WINDS N OF 27N W OF 138W. THE COLD FRONT IS FORECAST TO REACH NEAR 30N140W BY LATE SUN...AND EXTEND FROM 30N136W TO 21N140W BY MON MORNING. FRESH TO LOCALLY STRONG WINDS ARE EXPECTED IN THE WAKE OF THE FRONT WITH BUILDING SEAS OF 13-14 FT. SEAS ASSOCIATED WITH AN EARLIER TRAIN OF NW SWELL CONTINUE TO SUBSIDE ACROSS THE WATERS W OF 120W. THE WAVE MODELS INDICATE THAT THIS SWELL EVENT WILL SUBSIDE TO LESS THAN 8 FT THROUGH LATE SUNDAY. AT THIS TIME...A NEW ROUND OF NW SWELL WILL REACH THE FAR NW CORNER OF THE AREA IN ASSOCIATION WITH THE AFOREMENTIONED COLD FRONT. GAP WINDS...IN ADDITION TO STRONG GAP WIND EVENTS THROUGH THE GULF OF TEHUANTEPEC AND PAPAGAYO...INCREASING N TO NE WIND FLOW OVER THE SW CARIBBEAN CONTINUES TO SPILL ACROSS PANAMA AND THE GULF OF PANAMA AND ALL THE WAY TO NEAR 02N. EXPECT NORTHERLY WINDS OF 20-30 KT WITH SEAS TO 10 FT OVERNIGHT TONIGHT INTO SUN MORNING. WINDS WILL DIMINISH TO 20-25 KT DURING THE AFTERNOON AND EVENING HOURS...AND WILL CONTINUE DIMINISHING ON MON. GULF OF FONSECA...HIGH PRESSURE OVER THE NORTHERN GULF OF MEXICO IS ALSO ENHANCING THE GRADIENT ACROSS THE MOUNTAINOUS AREAS OF GUATEMALA...HONDURAS AND EL SALVADOR. ALONG WITH OVERNIGHT DRAINAGE FLOW...THIS IS RESULTING IN FRESH TO STRONG WINDS DOWNSTREAM OF THE GULF OF FONSECA. THE PRESSURE GRADIENT WILL RELAX LATE SUN INTO MON ALLOWING THE WINDS TO DIMINISH TO 20 KT OR LESS BY MON. $$ GR