000 AXPZ20 KNHC 112141 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC TUE FEB 11 2014 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 2015 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC...A COLD FRONT OVER THE NW GULF OF MEXICO IS SPREADING HIGH PRESSURE SOUTHWARD IN ITS WAKE ALONG THE EASTERN SLOPES OF THE SIERRA MADRE ORIENTAL MOUNTAINS. THE FRONT WILL MOVE THROUGH CHIVELA PASS BY WED EVENING...SENDING A BLAST OF NORTHERLY WINDS INTO THE GULF OF TEHUANTEPEC. WINDS WILL QUICKLY INCREASE TO GALE FORCE. THE GALE WILL BE SHORT LIVED...WITH CONDITIONS EXPECTED TO DIMINISH TO 30 KT BY THE END OF THE FORECAST PERIOD THU AFTERNOON AS THE COLD FRONT RACES EASTWARD OVER THE GULF OF MEXICO AND THE PRESSURE GRADIENT THROUGH CHIVELA PASS WEAKENS. THE GALE FORCE WINDS ARE EXPECTED TO PEAK AT 35 KT WITH SEAS TO 12 FT WED NIGHT INTO THU. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 09N83W TO 06N90W. THE ITCZ AXIS WAS ANALYZED FROM 06N90W TO 05N125W TO 06N140W. SCATTERED MODERATE CONVECTION WAS NOTED FROM 03N TO 07N BETWEEN 81W AND 88W AS WELL AS WITHIN 300 NM N OF THE AXIS BETWEEN 118W AND 134W. ...DISCUSSION... SOUTHWEST FLOW ON THE S SIDE OF AN UPPER LOW NEAR 17N130W IS TAPPING INTO DEEP LAYERED TROPICAL MOISTURE ALONG THE ITCZ W OF 125W AS SEEN IN PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 300 NM N OF THE AXIS BETWEEN 118W AND 134W. THIS CONVECTION IS BEING ENHANCED BY UPPER DIFFLUENCE ASSOCIATED WITH THE REAR RIGHT QUADRANT OF THE SOUTHWESTERLY UPPER JET. THE LOW IS FORECAST TO REMAIN QUASI-STATIONARY AS THE UPPER JET STRENGTHENS AND TURNS MORE SOUTHERLY. PRECIPITATION SHOULD CONTINUE NEAR THIS PORTION OF THE ITCZ OVER THE NEXT TWO DAYS AS A RESULT. BROAD UPPER DIFFLUENCE IS ALSO ENHANCING CONVECTION S OF THE MONSOON TROUGH AXIS FROM 03N TO 07N BETWEEN 81W AND 88W. DIFFLUENCE HERE IS ATTRIBUTABLE TO AN UPPER RIDGE AXIS THAT SPANS FROM AN ANTICYCLONE OVER WESTERN COLOMBIA TO THE GALAPAGOS ISLANDS. THE RIDGE AXIS IS EXPECTED TO SHIFT NORTHWARD TO 07N OVER THE NEXT FEW DAYS. THIS WILL ALLOW THE BEST CHANCE OF PRECIPITATION TO SHIFT NORTHWARD AND CLOSER TO THE COAST. THE 1028 MB SUBTROPICAL HIGH NEAR 33N128W EXTENDS A RIDGE AXIS INTO THE FORECAST AREA THROUGH 25N123W TO 19N110W. THE ASCAT-B PASS FROM 1815 UTC SHOWS FRESH TO STRONG TRADE WINDS SPAN THE AREA FROM 06N TO 24N W OF 122W...WITH THE SOUTHEAST CORNER OF THIS AREA...WITHIN THE AREA OF CONVECTION PREVIOUSLY NOTED...SEEING A STRONG PRESSURE GRADIENT BETWEEN THE SUBTROPICAL RIDGE AND ENHANCED LOW-LEVEL TROUGHING ATTRIBUTABLE TO THE AFOREMENTIONED UPPER LOW. A BELT OF FRESH TO STRONG NW WINDS APPROXIMATELY 150 NM OFF THE COAST OF SOUTHERN CALIFORNIA ON THE E SIDE OF THE SUBTROPICAL HIGH IS BEGINNING TO DIMINISH AND THE NW SWELL OFF THE PACIFIC COAST OF BAJA CALIFORNIA NORTE ATTRIBUTED TO THESE WINDS HAS SUBSIDED BELOW 8 FT THIS AFTERNOON. THE SUBTROPICAL HIGH IS FORECAST TO REMAIN QUASI- STATIONARY AS IT IS ENCROACHED UPON BY A COLD FRONT CURRENTLY FOUND TO ITS NW. THIS FRONT IS NOT EXPECTED TO MAKE IT INTO THE FORECAST AREA. TRADE WINDS WILL DIMINISH BELOW A STRONG BREEZE BY WED AS THE SUBTROPICAL HIGH WEAKENS. GULF OF PAPAGAYO...FRESH TO STRONG NE WINDS THAT HAD PULSED IN THE MORNING HOURS THROUGH THE GULF OF PAPAGAYO WILL TAKE A BREAK OVER THE NEXT FEW DAYS AS THE PRESSURE GRADIENT RELAXES IN ADVANCE OF THE COLD FRONT EXPECTED TO BRING GALE FORCE WINDS TO THE GULF OF TEHUANTEPEC. WINDS ARE EXPECTED TO ONCE AGAIN BECOME A STRONG BREEZE IN THE EARLY MORNING HOURS FRI...JUST AFTER THE OFFICIAL FORECAST PERIOD...AS THE COLD FRONT STRETCHES SOUTHWARD THROUGH CENTRAL AMERICA. $$ SCHAUER