000 AXPZ20 KNHC 131534 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC TUE JAN 13 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1500 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...THE PRESSURE GRADIENT REMAINS STRONG BETWEEN RIDGING EXTENDING FROM NE MEXICO TOWARD THE ISTHMUS OF TEHUANTEPEC AND TROUGHING TO THE S ALONG THE ITCZ. WINDS TO MINIMAL GALE FORCE ARE EXPECTED THROUGH THE END OF THE FORECAST PERIOD ON THURSDAY MORNING...WITH THE AREA OF GALE FORCE WINDS EXPECTED TO BE A BIT LARGER DURING THE PERIOD OF MAXIMUM DRAINAGE FLOW OFF THE MOUNTAINS IN THE EARLY MORNINGS AND A BIT SMALLER DURING THE DIURNAL MINIMUM OF DRAINAGE FLOW IN THE LATE AFTERNOON. SEAS IN THE 8-12 FT RANGE ARE EXPECTED IN THE GULF OF TEHUANTEPEC THROUGH THURSDAY MORNING. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH 07N78W TO 09N85W TO 06N90W. THE ITCZ CONTINUES FROM 06N90W TO 05N95W TO 07N110W TO 09N120W TO 10N132W TO 08N140W. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG FROM 07N TO 08N BETWEEN 106W AND 108W. WIDELY SCATTERED MODERATE TO ISOLATED STRONG FROM 04N TO 06N BETWEEN 81W AND 88W. A SURFACE TROUGH IS ALONG 08N74W IN COLOMBIA...TO 06N75W...TO 05N77W...AND TO 02N80W. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 03N TO 04N BETWEEN 77W AND 79W. ...DISCUSSION... A BROAD UPPER LEVEL TROUGH IS ALONG 130W. A SURFACE TROUGH IS ALONG 123W/124W FROM 09N TO 20N...25W TO 11N125W. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 08N TO 13N BETWEEN 117W AND 122W. PRECIPITABLE WATER IMAGERY SHOWS THE MOISTURE POOLED ALONG THE ITCZ IS SPREAD OUT ACROSS THE AREA JUST AHEAD OF THESE SURFACE TROUGHS. MOISTURE SHOULD CONTINUE TO BE PLENTIFUL ACROSS THIS AREA FOR THE NEXT FEW DAYS. THE TROUGH SHOULD REMAIN MORE CONVECTIVELY ACTIVE THROUGH THE FORECAST PERIOD AS IT WILL TRACK EASTWARD IN TANDEM WITH THE AREA OF VERTICAL LIFT ASSOCIATED WITH THE REAR RIGHT QUADRANT OF THE SOUTHERLY JET THAT IS ON THE EASTERN SIDE OF THE UPPER LEVEL TROUGH. THE SUBTROPICAL RIDGE EXTENDS FROM 1028 MB HIGH PRESSURE NEAR 38N128W THROUGH 32N126W TO 21N112W AND TO 12N104W. THE PRESSURE GRADIENT REMAINS STRONG BETWEEN THE SUBTROPICAL RIDGE AND THE 123W/124W SURFACE TROUGH. THE LATEST SCATTEROMETER DATA SHOW 20 KNOT TO 30 KNOT EASTERLY WINDS FROM 10N TO 13N BETWEEN 127W AND 134W AND FROM 15N TO 17N BETWEEN 128W AND 134W. THE RIDGE IS EXPECTED TO WEAKEN DURING THE NEXT TWO DAYS...DIMINISHING THE PRESSURE GRADIENT. TRADE WINDS ARE EXPECTED TO DIMINISH BELOW THE LEVEL OF A FRESH TO STRONG BREEZE BY LATE WEDNESDAY MORNING AS A RESULT. THE ACCOMPANYING AREA OF SEAS 8 FEET OR GREATER WILL SHRINK SIGNIFICANTLY AS THE WIND SPEEDS DECREASE. A WEAK COLD FRONT IS EXPECTED TO MOVE INTO NW WATERS LATER TODAY AND DISSIPATE FROM 30N135W TO 28N136W WEDNESDAY MORNING...WITH A TROUGH ALSO FROM 28N136W TO 14N136W. EXPECT A FRESH SOUTH BREEZE JUST AHEAD OF THE FRONT TODAY...WITH SEAS BUILDING TO 12 FT IN NW SWELL IN THE FAR NW WATERS BY THIS EVENING. THE NW SWELL WILL CONTINUE TO SEND SEAS OF 8 FT OR GREATER SOUTHEASTWARD INTO THE FORECAST AREA...SPANNING THE AREA W OF 126W N OF A LINE FROM 15N126W TO 9N140W BY THE END OF THE FORECAST PERIOD EARLY THURSDAY 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 WED MORNING AND THU MORNING DURING THE MAXIMUM NOCTURNAL DRAINAGE FLOW. WINDS AND SEAS WILL DIMINISH BRIEFLY DURING THE AFTERNOON AND EVENING HOURS. GULF OF CALIFORNIA...AN UPPER LOW OVER THE U.S. GREAT BASIN WILL MAKE ITS WAY S TO THE ARIZONA/MEXICO BORDER WED BEFORE SHEARING EASTWARD 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 WED AND THU. A FRESH N BREEZE IS EXPECTED OVER THE NORTHERN GULF OF CALIFORNIA WED...WITH AN OCCASIONAL STRONG BREEZE BY THU MORNING. $$ MT