000 AXPZ20 KNHC 160337 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC FRI JAN 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 0300 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...STRONG NORTHERLY FLOW BETWEEN A COLD FRONTAL BOUNDARY MOVING SE ACROSS THE EASTERN BAY OF CAMPECHE AND A STRENGTHENING RIDGE ALONG THE NE MEXICAN COAST CONTINUES TO FUNNEL THROUGH THE ISTHMUS OF TEHUANTEPEC AND ACROSS THE GULF OF TEHUANTEPEC. WINDS HAVE BEGUN TO STRENGTHEN BOTH ACROSS THE SW GULF OF MEXICO AND ACROSS TEHUANTEPEC THIS EVENING...AND WERE ESTIMATED AT MINIMAL GALE FORCE AT 0000 UTC THIS EVENING. STRENGTHENING HIGH PRESSURE ACROSS THE WESTERN GULF AND EASTERN MEXICO WILL INCREASE WINDS FURTHER OVERNIGHT AND FRI MORNING...AND ARE EXPECTED TO REACH 30-40 KT LATE TONIGHT THROUGH MOST OF THE DAY FRI. WINDS ARE THEN EXPECTED TO DIMINISH SLIGHTLY TO MINIMAL GALE FORCE WINDS FRI NIGHT THROUGH SUNRISE SAT...THEN DIMINISHING TO 20-30 KT FOR ABOUT 18-24 HOURS BEFORE THE NEXT ROUND OF GALE FORCE WINDS START SUN EVENING. LATEST WAVE MODEL GUIDANCE INDICATES SEAS OF 10-15 FT BY FRI MORNING DURING THE STRONGEST WINDS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 08N71W TO 09N84W TO 04N99W... WHERE IT TRANSITIONS TO ITCZ...CONTINUING ON TO 07N116W TO BEYOND 06N140W. ISOLATED TO SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 60 NM N AND 150 NM S OF TROUGH BETWEEN 90W AND 97W. SCATTERED TO NUMEROUS MODERATE TO STRONG CONVECTION WAS NOTED FROM 09.5N TO 18N BETWEEN 113W AND 117W. ...DISCUSSION... THE SUBTROPICAL RIDGE EXTENDS FROM 1024 MB HIGH PRESSURE JUST N OF THE AREA NEAR 33N126W THROUGH 29N122W TO 18N107W. A SURFACE TROUGH LIES N OF THE ITCZ FROM 09N123W TO DEVELOPING 1010 MB LOW PRES NEAR 14.5N119W...AND IS ASSOCIATED WITH MID-LEVEL ENERGY FOUND WITHIN A BROAD DEEP LAYERED TROUGH BETWEEN 108W AND 128W. THIS MIDDLE TO UPPER LEVEL TROUGH IS EXPECTED TO CUT OFF A DEEP LAYER LOW NEAR 13N123W OVER THE NEXT 24-48 HOURS. THE DEVELOPING SURFACE LOW IS FORECAST TO MOVE NW THROUGH SUN...WHILE THE PRES GRADIENT BETWEEN THE LOW AND THE EXPANDING SUBTROPICAL RIDGE SHOULD BE STRONG ENOUGH TO SUPPORT FRESH TO STRONG WINDS ON THE N AND NW SIDES OF THE LOW...POSSIBLY INCREASING BRIEFLY TO NEAR GALE FORCE FRI. THIS LOW AND CONVERGING TRADEWINDS TO ITS N AND NE WILL ALSO CONTINUE TO BE A FOCUS FOR DEEP CONVECTION. GULF OF PAPAGAYO...TRADE WINDS IN THE SW CARIBBEAN SEA CONTINUE TO FUNNEL THROUGH THE HIGHER ELEVATIONS OF NORTHERN COSTA RICA INTO THE GULF OF PAPAGAYO. THESE WINDS DIMINISHED THIS AFTERNOON TO 15-20 KT...BUT ANOTHER ROUND OF FRESH TO STRONG NE-E WINDS IS EXPECTED TONIGHT INTO EARLY FRI...AND AGAIN FRI NIGHT INTO EARLY SAT DURING THE PERIOD OF MAXIMUM NOCTURNAL DRAINAGE FLOW. WINDS WITHIN 90 NM OF THE COAST ARE EXPECTED TO PEAK AT 25-30 KT EACH NIGHT...WITH SEAS BUILDING UP TO 8-9 FT. GULF OF PANAMA...FRESH NORTHERLY WINDS ARE EXPECTED IN THE WESTERN GULF OF PANAMA AND JUST SE-S OF THE AZUERO PENINSULA DUE TO A TIGHT PRESSURE GRADIENT ACROSS THE AREA...AND WILL INCREASE TO AROUND 20 KT N OF 06N TONIGHT AND AGAIN FRI NIGHT. SEAS OF 4-6 FT WILL INCREASE TO 5-7 FT DURING THE PERIODS OF STRONGEST WINDS. GULF OF CALIFORNIA... A SLOW MOVING POSITIVELY TILTED UPPER TROUGH WILL MOVE EASTWARD THROUGH THE SW UNITED STATES OVER THE NEXT FEW DAYS. AT THE SURFACE...THE PRESSURE GRADIENT WILL BUILD BETWEEN LEE SIDE TROUGHING ALONG THE W SLOPES OF THE SIERRA MADRE OCCIDENTAL AND INCREASED RIDGING OVER THE GREAT BASIN IN THE WAKE OF THE UPPER TROUGH. THE LATEST MODEL GUIDANCE INDICATES NW-N WINDS INCREASING TO 20-25 KT IN THE NORTHERN GULF OF CALIFORNIA N OF 28.5N THIS EVENING AND EARLY TONIGHT... DIMINISHING LATE FRI MORNING AS THE PRESSURE GRADIENT WEAKENS. $$ STRIPLING