000 AXPZ20 KNHC 030327 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE FEB 03 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 0200 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...A COLD FRONT HAS RACED S THROUGH THE WESTERN GULF OF MEXICO AND HAS BROUGHT GALE FORCE WINDS TO THE GULF OF TEHUANTEPEC THIS EVENING. THE 1530 UTC ASCAT-B PASS HAD SHOWED 25 KT WINDS WERE ALREADY FUNNELING INTO THE GULF OF TEHUANTEPEC. SINCE THEN...THE PRESSURE GRADIENT HAS TIGHTENED ACROSS SE MEXICO BETWEEN HIGH PRESSURE OVER S TEXAS BEHIND THE FRONT AND LOWER PRESSURE TO THE S ALONG THE ITCZ. A CUT OFF LOW WITHIN THE SOUTHERN STREAM CURRENTLY OVER THE GULF OF CALIFORNIA WILL MOVE EASTWARD INTO NW MEXICO...ALLOWING THE MID TO LOW LEVEL FLOW OVER THE GULF OF MEXICO TO SHIFT MORE SOUTHEASTERLY AHEAD OF THE SYSTEM BY TUE. THE GALE WARNING IS FORECAST TO EXPIRE AFTER SUNRISE TUE AS A RESULT. WINDS ARE EXPECTED TO DIMINISH BELOW THE ADVISORY CRITERIA OF 20-25 KT BY WED AFTERNOON. SEAS HAD RAPIDLY BUILT TO 12 FT DURING THE EVENING AND WILL GRADUALLY SUBSIDE AS THE WINDS COME DOWN. GALE WARNING ACROSS THE FAR NW WATERS...A BROAD UPPER TROUGH CENTERED OVER THE CENTRAL PACIFIC SUPPORTS A FRONT JUST W OF THE NW PORTION OF THE FORECAST AREA. SEAS TO 9 FT IN NW SWELL CAN BE FOUND OVER THE NW PORTION AND SHOULD CONTINUE IN THIS AREA THROUGH TUE AFTERNOON. ON TUE...A NEW BATCH OF ENERGY ROUNDING THE S PORTION OF THE TROUGH OVER THE CENTRAL PACIFIC SHOULD ENERGIZE THE BOUNDARY. SOUTHERLY WINDS ARE EXPECTED TO INCREASE TO MINIMAL GALE FORCE ACROSS THE NW CORNER OF THE AREA BY WED MORNING AHEAD OF THE COLD FRONT FORECAST. GALE CONDITIONS ARE FORECAST TO CONTINUE AHEAD OF THE FRONT THROUGH THE END OF THE FORECAST PERIOD WED EVENING. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 05N77W TO 05N93W. THE ITCZ AXIS WAS ANALYZED FROM 05N93W TO 07N117W TO 06N140W. ISOLATED MODERATE CONVECTION WAS WITHIN 120 NM N OF THE AXIS BETWEEN 97W AND 113W. SCATTERED MODERATE CONVECTION WAS WITHIN 150 NM EITHER SIDE OF THE AXIS W OF 128W. ...DISCUSSION... A 1022 MB SUBTROPICAL HIGH PRESSURE CENTER NEAR 34N128W SENDS A RIDGE AXIS SE THROUGH 30N128W TO 17N110W AND ANOTHER SW TO BEYOND 26N140W. THIS HIGH HAS WEAKENED AND SHIFTED N OVER THE PAST 24 HOURS...SLACKENING THE PRESSURE GRADIENT BETWEEN THE SUBTROPICAL HIGH AND THE ITCZ. TRADE WINDS HAVE WEAKENED TO A FRESH BREEZE AS A RESULT. WINDS AND SEAS HERE WILL RAPIDLY DIMINISH BY WED AS THE SUBTROPICAL HIGH WEAKENS AND IS PUSHED E BY THE COLD FRONT ASSOCIATED WITH THE GALE WARNING OVER NW WATERS. AS MENTIONED IN THE SPECIAL FEATURES SECTION ABOVE...A MID TO UPPER LEVEL LOW HAS CUT OFF FROM THE NORTHERN STREAM AND LIES OVER THE GULF OF CALIFORNIA. SOUTHWEST FLOW ON THE SE SIDE OF THIS CUT OFF LOW IS PUMPING MOISTURE INTO THE CENTRAL MEXICAN COAST. CONVECTION CONTINUES TO BE FOCUSED ON AN ASSOCIATED SURFACE TROUGH FROM 20N105W TO 13N110W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS WITHIN 330 NM SE AND S OF THE TROUGH AS WELL AS ALONG THE W SLOPES OF THE SIERRA MADRE OCCIDENTAL FROM 23N TO 29N...WITH WIDESPREAD SHOWERS FOUND OVER MUCH OF MAINLAND MEXICO PRIMARILY E OF 109W. THE CUT OFF LOW IS FORECAST TO WEAKEN AND MOVE NE INTO TEXAS....BUT THE LOCATION OF THE SW JET PROPELLING MOISTURE INTO MEXICO SHOULD CHANGE LITTLE THROUGH TUE. THIS WILL KEEP THE PRECIPITATION ASSOCIATED WITH THE SYSTEM FOCUSED ALONG THE COAST BETWEEN MANZANILLO AND MAZATLAN INLAND TO N CENTRAL AND NORTHEASTERN MEXICO THROUGH TUE BEFORE SHIFTING NE. GAP WINDS... GULF OF PAPAGAYO...WINDS AND SEAS ARE CURRENTLY BELOW ADVISORY CRITERIA...BUT WINDS ARE FORECAST TO INCREASE TO 20-25 KT LATE TONIGHT THROUGH SUNRISE TUESDAY AS HIGH PRESSURE BUILDS OVER THE WESTERN CARIBBEAN. ASSOCIATED SEAS WILL BUILD TO 9 FT DURING THAT PERIOD. THESE DIURNALLY PULSING MARINE CONDITIONS ARE EXPECTED TO CONTINUE THROUGH WED. $$ SCHAUER