000 AXPZ20 KNHC 030945 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC FRI APR 03 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. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...A NEW COLD FRONT WILL MOVE ACROSS THE NORTHERN GULF OF MEXICO DURING THE UPCOMING WEEKEND. HIGH PRES IN THE WAKE OF THE FRONT WILL EXTEND A RIDGE ACROSS THE WESTERN GULF INTO THE ISTHMUS THE TEHUANTEPEC. NORTHERLY WINDS OF 20-25 KT ARE EXPECTED TO SURGE INTO THE GULF OF TEHUANTEPEC EARLY SAT...GRADUALLY INCREASE THROUGHOUT THE DAY ON SAT REACHING MINIMAL GALE FORCE SAT NIGHT INTO EARLY SUN MORNING. SEAS ARE FORECAST TO BUILD TO AROUND 12 FT WITH THE STRONGEST WINDS. THEN...WINDS ARE EXPECTED TO BE BELOW GALE FORCE BY SUN AFTERNOON. A GALE WARNING HAS BEEN ISSUED WITH THE 0600 UTC FORECAST PACKAGE. THIS IS FORECAST TO BE A SHORT-LIVED GALE FORCE WIND EVENT. CLIMATOLOGICALLY...THE FINAL GALE FOR WIND EVENT OCCURS IN THE GULF OF TEHUANTEPEC IN LATE MARCH OR EARLY APRIL. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE ITCZ AXIS EXTENDS FROM 06N91W TO 04N110W TO 03N120W TO 04N130W TO BEYOND 06N140W. SCATTERED MODERATE CONVECTION IS NOTED FROM 04N TO 08N BETWEEN 91W AND 100W AND FROM 03N TO 05N BETWEEN 100W AND 121W. THE SECOND ITCZ THAT HAS BEEN LOCATED SOUTH OF THE EQUATOR DURING THE PREVIOUS DAYS IS NO IDENTIFIABLE BASED ON SATELLITE IMAGERY AND SURFACE DATA. COMPUTER MODEL CONTINUES TO SUGGEST THE PRESENCE OF THIS FEATURE OVER THE NEXT 48 HOURS. ...DISCUSSION... A 1036 MB SUBTROPICAL HIGH IS ANALYZED NEAR 37N143W. A RIDGE EXTENDS FROM THE HIGH ACROSS THE NORTHERN FORECAST WATERS TO NEAR 20N110W. THE PRESSURE GRADIENT BETWEEN THE RIDGE AND A TROUGH OVER NW MEXICO IS SUPPORTING MODERATE TO FRESH NORTHERLY WINDS JUST OFF THE BAJA CALIFORNIA PENINSULA. SCATTEROMETER DATA PROVIDED OBSERVATIONS OF 20-25 KT NE-E WINDS N OF 18N W OF 130W AND FROM 08N TO 12N W OF 130W. THESE WINDS ARE ASSOCIATED WITH THE PRESSURE GRADIENT BETWEEN THE HIGH AND LOWER PRES IN THE VICINITY OF THE ITCZ. A PAIR OF ALTIMETER PASSES INDICATED SEAS OF 8-10 FT IN THIS AREA. THE HIGH PRES WILL REMAIN NEARLY STATIONARY OVER THE NEXT 12-24 HOURS THEN SHIFT SLIGHTLY TO THE W. THE PRES GRADIENT WILL REMAIN TIGHT ENOUGH TO PRODUCE AN AREA OF FRESH TO STRONG NE-E WINDS FROM 09N TO 20N W OF 130W...AND FROM 20N TO 25N W OF 135W BY FRI NIGHT. THE AERIAL EXTENT OF THE TRADES WILL DECREASE BY SAT NIGHT AS THE SUBTROPICAL HIGH WEAKENS. NW SWELL WILL CONTINUE TO COMBINE WITH NE WIND WAVES TO BUILD SEAS TO 9 FT W OF A LINE FROM FROM 26N140W TO 20N130W TO 10N130W TO 05N140W BY FRI NIGHT WHEN ADDITIONAL PULSES OF NW SWELL WILL REACH THE FAR NW CORNER OF THE AREA. MAINLY GENTLE TO MODERATE WINDS PREVAIL ELSEWHERE ACROSS THE REGION E OF 110W EXCEPT FOR GAP WINDS OF 20-25 KT DOWNWIND FROM THE GULF OF PAPAGAYO. LONG PERIOD CROSS EQUATORIAL SOUTHWESTERLY SWELL DOMINATES THE REGION AND IS ALREADY REACHING THE COASTS OF CENTRAL AMERICA AND MEXICO. A SURFACE TROUGH EXTENDS OVER COLOMBIA AND ENTERS THE EPAC NEAR 05N77W TO 02N79W. A CLUSTER OF MODERATE TO ISOLATED STRONG CONVECTION IS FROM 05N TO 07N E OF 78W TO THE COAST OF COLOMBIA. GAP WINDS... GULF OF PAPAGAYO...PULSING OF NOCTURNAL WINDS ARE EXPECTED IN THE GULF OF PAPAGAYO THROUGH SAT MORNING...REACHING 20-25 KT BETWEEN 0600 AND 1200 UTC...WITH COMBINED SEAS OF 6-7 FT DOWNWIND OF THE GULF. A STRONGER GAP WIND EVENT IS EXPECTED ACROSS THIS GULF ON SUN...WITH WINDS OF 25 KT EXTENDING SW AND DOWNWIND TO NEAR 92W WITH BUILDING SEAS TO 9 FT. THIS WILL BE ASSOCIATED WITH A HIGH PRES BUILDING ACROSS THE NW CARIBBEAN AND NORTHERN CENTRAL AMERICA. GULF OF PANAMA...MODERATE TO FRESH NORTHERLY WINDS ARE EXPECTED ACROSS THE GULF OF PANAMA AND DOWNWIND TO ABOUT 06N OVER THE NEXT COUPLE OF DAYS WITH SEAS OF 5-6 FT. $$ GR