000 AXPZ20 KNHC 140911 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC WED JAN 14 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 0700 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...NORTHERLY FLOW BETWEEN A STALLED FRONTAL BOUNDARY OVER THE SW GULF OF MEXICO AND RIDGING ALONG THE NE MEXICAN COAST IS FUNNELING THROUGH THE ISTHMUS OF TEHUANTEPEC. THIS PATTERN SHOULD SEE LITTLE CHANGE OVER THE NEXT TWO DAYS. WINDS TO MINIMAL GALE FORCE IN THE GULF OF TEHUANTEPEC ARE EXPECTED TO CONTINUE THROUGH THE END OF THE FORECAST PERIOD ON FRI MORNING...WITH THE AREA OF GALE FORCE WINDS EXCEPTED TO BE LARGER DURING THE PERIOD OF MAXIMUM DRAINAGE FLOW OFF THE MOUNTAINS IN THE EARLY MORNINGS AND SMALLER DURING THE DIURNAL MINIMUM OF DRAINAGE FLOW IN THE LATE AFTERNOON. SEAS IN THE 9-13 FT RANGE ARE EXPECTED IN THE GULF OF TEHUANTEPEC THROUGH FRI MORNING. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 07N78W TO 09N84W TO 06N90W. THE ITCZ AXIS WAS ANALYZED FROM 06N90W TO 04N97W TO 08N115W TO 07N127W TO 09N137W TO 08N140W. SCATTERED MODERATE TO STRONG CONVECTION WAS WITHIN 300 NM N AND 45 NM S OF THE AXIS BETWEEN 112W AND 117W. SCATTERED MODERATE CONVECTION WAS WITHIN 120 NM S OF THE AXIS BETWEEN 85W AND 88W AS WELL AS WITHIN 120 NM N OF THE AXIS BETWEEN 125W AND 128W. ...DISCUSSION... A BROAD UPPER TROUGH IS CENTERED ALONG 125W. A STRONG SHORTWAVE NEAR 14N120W REFLECTS A TROUGH AT THE SURFACE FROM 12N116W TO 06N115W. PRECIPITABLE WATER IMAGERY SHOWS LOW-TO MID-LEVEL MOISTURE POOLED ALONG THE ITCZ IN THIS AREA...WITH MODERATE TO STRONG CONVECTION NOTED HERE IN INFRARED IMAGERY AND SUPPORTED BY LIGHTNING DATA. THIS SHORTWAVE WILL MOVE RAPIDLY NORTHEASTWARD AWAY FROM THE AREA OF POOLED MOISTURE AS A NEW BATCH OF SHORTWAVE ENERGY MOVES INTO THE BACKSIDE OF THE BROAD TROUGH. THIS NEW ENERGY WILL BECOME THE FOCUS FOR PRECIPITATION BY THU AS IT MOVES INTO THE LEADING EDGE OF THE BROAD UPPER TROUGH. THE SUBTROPICAL RIDGE EXTENDS FROM 1022 MB HIGH PRESSURE NEAR 34N126W THROUGH 27N120W TO 20N107W. THE PRESSURE GRADIENT HAS WEAKENED A BIT BETWEEN THE SUBTROPICAL RIDGE AND THE AFOREMENTIONED SURFACE TROUGH OVER CENTRAL WATERS. THE ASCAT-A PASS FROM 0518 UTC SHOWS FRESH TO STRONG TRADE WINDS FROM 09N TO 11N BETWEEN 111W AND 114W. THE RIDGE WILL CONTINUE TO WEAKEN OVER THE NEXT TWO DAYS...RELAXING THE PRESSURE GRADIENT. TRADE WINDS ARE EXPECTED TO DIMINISH BELOW A FRESH TO STRONG BREEZE ON THU AS A RESULT. THE ACCOMPANYING AREA OF SEAS 8 FT OR GREATER WILL SHRINK SIGNIFICANTLY AS THE WINDS DROP OFF. A WEAK COLD FRONT LIES OVER NW WATERS FROM 30N136W TO 27N140W. THE 0618 UTC ASCAT-B PASS SHOWS WINDS ARE A FRESH S BREEZE JUST AHEAD OF THE FRONT. SEAS OVER 8 FT IN NW SWELL HAVE MOVED OUT AHEAD OF THE FRONT...BUT THE HIGHEST SEAS...TO 13 FT...LIE W OF THE FRONT. THE NW SWELL WILL CONTINUE TO SEND SEAS OF 8 FT OR GREATER SOUTHEASTWARD INTO THE FORECAST AREA...SPANNING THE AREA W OF A LINE FROM 30N124W TO 14N133W TO 10N140W BY THE END OF THE FORECAST PERIOD EARLY FRI MORNING. GAP WINDS... GULF OF PAPAGAYO...TRADE WINDS IN THE SW CARIBBEAN CONTINUE TO FUNNEL THROUGH NORTHERN COSTA RICA INTO THE GULF OF PAPAGAYO. FRESH TO STRONG E-NE WINDS IN PLACE THIS MORNING ARE ALSO EXPECTED THU MORNING AND FRI MORNING DURING THE PERIOD OF MAXIMUM NOCTURNAL DRAINAGE FLOW. WINDS AND SEAS WILL BRIEFLY DIMINISH DURING THE AFTERNOON AND EVENING HOURS. GULF OF CALIFORNIA...AN UPPER LOW OVER ARIZONA WILL SLOWLY MOVE SE TODAY BEFORE SHEARING EASTWARD INTO TEXAS THU. 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 SYSTEM TODAY AND THU. THE NORTHERN GULF OF CALIFORNIA HAS A FRESH N-NW BREEZE IN PLACE THIS MORNING AND MAY SEE AN OCCASIONAL STRONG BREEZE N OF 28N DURING THE NEXT DAY OR SO. $$ SCHAUER