000 AXPZ20 KNHC 162211 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2115 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...STRONG NORTHERLY FLOW BETWEEN A COLD FRONT APPROACHING THE YUCATAN PENINSULA IN THE GULF OF MEXICO...AND STRONG RIDGING ALONG THE EASTERN MEXICAN COAST CONTINUES TO FUNNEL THROUGH THE ISTHMUS OF TEHUANTEPEC AND ACROSS THE GULF OF TEHUANTEPEC. EARLY AFTERNOON ASCAT PASSES SHOWED WINDS CONTINUING IN 30 TO 40 KT RANGE ACROSS THE GULF OF TEHUANTEPEC...BUT WILL DIMINISH TO 30-35 KT EARLY TONIGHT...THEN FALL BELOW GALE FORCE SATURDAY MORNING AS THE RIDGING ACROSS THE WESTERN GULF OF MEXICO BEGINS TO WEAKEN. A SMALL POCKET OF FRESH TO STRONG NORTHERLY WINDS WILL PERSIST IN THE IMMEDIATE GULF OF TEHUANTEPEC THROUGH SUN MORNING. THE LATEST WAVE MODEL GUIDANCE INDICATES MAXIMUM SEAS BUILDING 15 TO 17 FT THIS AFTERNOON THEN SUBSIDING TO 8-12 FT OVERNIGHT TONIGHT INTO EARLY SAT...THEN TO 8-10 FT OVERNIGHT SAT INTO EARLY SUN. THE NEXT ROUND OF GALE FORCE WINDS IS EXPECTED TO START SUN EVENING INTO MON MORNING. A GALE WARNING HAS BEEN ISSUED FOR A 1008 MB LOW PRESSURE CENTER NEAR 17N118W...WITH RECENT ASCAT PASSES SHOWING MINIMAL GALE FORCE WINDS OCCURRING WITHIN 120 NM ACROSS THE NE SEMICIRCLE.... WITH SEAS 10 TO 13 FT...WHILE STRONG TRADEWINDS OCCURRING BETWEEN HIGH PRES TO THE N AND THE LOW WERE LOCATED WITHIN 150 NM SE QUADRANT AND 240 NM NW SEMICIRCLE. SCATTERED MODERATE TO STRONG CONVECTION WAS NOTED WITHIN 150 NM N QUADRANT OF LOW. THIS LOW CENTER IS ASSOCIATED WITH MIDDLE TO UPPER LEVEL ENERGY NOTED ON WATER VAPOR IMAGERY WITHIN A BROAD DEEP LAYERED TROUGH BETWEEN 108W AND 129W. THIS TROUGHING ALOFT HAS CUT OFF A DEEP LAYER LOW NEAR 17N124W WHICH WILL DRIFT E-SE THROUGH EARLY NEXT WEEK. SATELLITE IMAGERY SUGGESTS THE LOW HAS ALREADY REACHED ITS PEAK INTENSITY...AND IS CURRENTLY BECOMING ELONGATED N-NW TO S- SE...WHILE CONVECTION OCCURRING ACROSS THE N SEMICIRCLE HAS ALSO BEGUN TO DIMINISH. GALE FORCE WINDS ASSOCIATED WITH THE LOW WILL THUS END BY EARLY EVENING. HOWEVER...THE PRESSURE GRADIENT BETWEEN THE LOW AND THE FAIRLY STATIONARY SUBTROPICAL RIDGE TO THE N WILL BE STRONG ENOUGH TO SUPPORT 20-30 KT WINDS ON THE NORTHERN PERIPHERY OF THE LOW CENTER THROUGH SUN AS IT SHIFTS NW...BUILDING MAINTAINING SEAS UP TO 12 FT TONIGHT AND TO 11 FT SAT. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 09N74W TO 05N84W TO 07N88W...THEN TRANSITIONS TO ITCZ...CONTINUING ON TO 05N101W TO 09N115W THEN RESUMES FROM 08N120W TO 06N140W. SCATTERED MODERATE ISOLATED STRONG FROM 02.5N TO 07N E OF 80W. SCATTERED MODERATE ISOLATED STRONG WITHIN 210 NM N OF ITCZ BETWEEN 105W AND 118W. ...DISCUSSION... THE SUBTROPICAL RIDGE EXTENDS FROM A 1026 MB HIGH NEAR 32N129W SE TO 24N113W AND ALSO SW FROM THE HIGH TO NEAR 26N140W. THE PRES GRADIENT BETWEEN THE GALE CENTER ABOVE AND THE RIDGE IS PRODUCING A BROAD ZONE OF FRESH NE TO E TRADEWINDS S OF 25N EXTENDING W OF 120 TO 140W...WITH ASSOCIATED WIND WAVE MERGING WITH FADING NW SWELL TO PRODUCE SEAS OF 8-10 FT ACROSS THIS AREA. THIS WAVE FIELD WILL DECAY SLIGHTLY AND BECOME CONFINED TO THE WATERS W OF 120W-125W BY SUN MORNING. GULF OF PAPAGAYO...SHARP AND STRONG RIDGING ACROSS CENTRAL AMERICA IS SUPPORTING FRESH TO STRONG NE-E WINDS IN AND DOWNWIND OF PAPAGAYO BUILDING SEAS UP TO 8-9 FT. WINDS WILL CONTINUE TO PULSE TO 20-25 KT DURING THE NIGHT AND EARLY MORNING HOURS THROUGH 48 HOURS...BRIEFLY INCREASING TO 30 KT DURING THE PERIOD OF MAXIMUM NOCTURNAL DRAINAGE FLOW JUST BEFORE SUNRISE...WITH A BRIEF LULL OF WINDS DIMINISHING TO 20 KT OR LESS DURING THE AFTERNOON HOURS. GULF OF PANAMA...FRESH TO LOCALLY STRONG NORTHERLY WINDS ARE PRESENT IN THE WESTERN GULF OF PANAMA AND S OF THE AZUERO PENINSULA DUE TO A TIGHT PRESSURE GRADIENT ACROSS THE AREA. WINDS WILL DIMINISH BY EARLY THIS AFTERNOON AS THE GRADIENT TEMPORARILY SLACKENS...THEN WILL RETURN THIS EVENING INTO EARLY SAT BEFORE DIMINISHING AGAIN. SEAS OF 4-6 FT WILL BUILD TO 5-8 FT THIS EVENING INTO EARLY SAT. GULF OF CALIFORNIA...FRESH TO STRONG NW-N WINDS IN THE N GULF N OF 29.5N HAVE DIMINISHED THIS AFTERNOON...AND ARE EXPECTED TO FALL TO 15 KT OR LESS TONIGHT THROUGH SAT. MEANWHILE THE PRES GRADIENT WILL INCREASE ACROSS S PORTIONS OF THE GULF S OF 25N...WHERE NW TO N WINDS ARE EXPECTED TO INCREASE TO AROUND 20 KT TONIGHT INTO SAT MORNING...AND SEAS BUILD TO 5 FT. $$ STRIPLING