000 AXPZ20 KNHC 050246 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC MON MAY 05 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0200 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 06N100W TO LOW PRES NEAR 09N111W 1010 MB TO 07N120W WHERE LOW LEVEL WINDS SUGGEST A TRANSITION TO ITCZ FROM WHICH EXTENDS TO BEYOND 06N140W. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 90 NM S QUADRANT OF THE LOW PRES NEAR 09N11W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION WAS ALSO NOTED FROM 10N TO 15N BETWEEN 95W AND 105W. ...DISCUSSION... GULF OF TEHUANTEPEC...SUSTAINED 20 KT FLOW IS NOTED AT SALINA CRUZ ON THE SOUTHERN END OF THE TEHUANTEPEC ISTHMUS...AND INDICATION THAT STRONG WINDS THROUGH THE GULF OF TEHUANTEPEC PERSIST. THIS WILL GRADUALLY DIMINISH MAINLY AFTER THE EARLY MORNING HOURS AS HIGH PRES N OF THE AREA WEAKENS AND SHIFTS EAST...THEN TO 20 KT OR LESS BY MON AFTERNOON. SEAS TO 11 FT WILL GRADUALLY SUBSIDE STARTING TOMORROW AS WINDS DIMINISH. A BURST OF CONVECTION FLARED NEAR THE CENTER OF THE 1010 MB LOW PRES CENTER NEAR 09N112W OVER THE PAST COUPLE OF HOURS...BUT HAS SINCE SUBSIDED. THE SPORADIC CONVECTION NEAR THIS LOW IS BEING SUPPORTED BY A NEGATIVELY TILTED SHORT WAVE TROUGH IN THE MID TO UPPER LEVELS OF THE ATMOSPHERE SITUATED TO THE NORTHWEST OF THE SURFACE LOW. ALTHOUGH THIS IS LIFTING NE AND OUT OF THE AREA...ADDITIONAL CONVECTION IS LIKELY TO FLARE OVERNIGHT NEAR THE CENTER AND MAY INCREASE MORE TOMORROW AHEAD OF A MORE SIGNIFICANT LONG WAVE TROUGH APPROACHING THE AREA FROM THE WEST. PROVIDED THIS DOES NOT IMPOSE SIGNIFICANT WESTERLY SHEAR OVER THE DEVELOPING CONVECTION. FARTHER EAST...THE CONVECTION IS MORE INTENSE...PERSISTENT AND WIDESPREAD BUT AS YET THERE IS NO WELL DEFINED LOW LEVEL CENTER. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION PERSISTS FROM 05N TO 10N BETWEEN 95W AND 105W. THE CONVECTION AS BEEN PULSING FOR THE PAST SEVERAL DAYS IN THIS AREA...AIDED BY FAVORABLE JET DYNAMICS ALOFT. IT HAS INCREASED TODAY WITH THE HELP OF CONSIDERABLE LOW LEVEL CONVERGENCE SUPPLIED BY THE RECENT GULF OF TEHUANTEPEC GALE EVENT. ASCAT DATA FROM SEVERAL HOURS AGO INDICATED 20 T0 25 KT WINDS REACHING AS FAR AS 12N100W. ASCAT SATELLITE DATA AND TOGA-TAO OBSERVATIONS FAR SOUTH SHOW LIGHT MOSTLY SE TO S WINDS...POSSIBLY INFLUENCED BY THE DEVELOPING LOW NEAR 09N112W. WITH THIS FLOW PATTERN THIS IS NO CLEAR MONSOON TROUGH AT LEAST FOR THE TIME BEING EAST OF 100W. THE 18 UTC GFS INITIALIZES WELL WITH THE LOW PRES NEAR 09N1112W BUT QUICKLY SHOWS THIS LOW BECOMING ABSORBED INTO A DEEPER LOW THAT WILL EMERGE OUT OF THE CONVECTIVE MASS FARTHER EAST NEAR 11N105W TOMORROW. THIS COULD BE AN INDICATION THAT THE WESTERLY SHEAR AHEAD OF THE APPROACHING TROUGH WILL LIMIT THE FURTHER DEVELOPMENT OF THE WESTERN MOST LOW. THE UKMET AND TO A LESSER EXTENT THE ECMWF FAVOR THE DEVELOPMENT OF THE WESTERN LOW THROUGH THE NEXT 48 HOURS. THE ECMWF COMES MORE INTO AGREEMENT WITH THE GFS POSITION THEREAFTER SHOWING THE EASTERN LOW DRIFTING N TO NE TOWARD THE CENTRAL COAST OF MEXICO THROUGH MID WEEK. THERE REMAIN SIGNIFICANT DIFFERENCES IN INTENSITY HOWEVER BY THAT TIME BETWEEN THE TWO MODELS WITH THE GFS MUCH DEEPER. THIS IS LIKELY DUE TO THE GFS SHOWING MINIMAL SHEAR ACROSS THE EASTERN MOST LOW. THE OFFICIAL FORECAST FOLLOWS THE GFS TREND FOR DEVELOPMENT AND POSITION BUT WITH A NOD TO THE ECMWF IN INTENSITY FOR LATER PERIODS. SPORADIC CONVECTION CONTINUES AS WELL IN THE VICINITY OF THE 1012 MB LOW PRES NEAR 09N111W. THIS IS IN PART ENHANCED BY A NEGATIVELY TILTED SHORT WAVE TROUGH IN THE MID TO UPPER LEVELS OF THE ATMOSPHERE TO THE NORTHWEST OF THE LOW. WHILE THIS IS EXPECTED TO LIFT TO THE NE OF THE AREA TONIGHT...GLOBAL MODELS ARE IN GOOD AGREEMENT SHOWING A MORE AMPLIFIED UPPER TROUGH APPROACHING THE AREA FROM THE WEST. GLOBAL MODELS CONTINUE TO DEMONSTRATE DECENT AGREEMENT AND CONSISTENCY SHOWING THE LOW PRES DEVELOPING SLOWLY MOVING TO THE NORTH AND NORTHEAST. FARTHER WEST...SCATTEROMETER DATA CONTINUE TO SHOW MODEST TRADE WIND FLOW INTO THE ITCZ TO THE SOUTH OF A WEAK SUBTROPICAL RIDGE. THE RIDGE IS EXPECTED TO BUILD OVER THE NEXT COUPLE OF DAYS. THE PRES GRADIENT SHOULD TIGHTEN SLIGHTLY BETWEEN THE BUILDING RIDGE TO THE NORTH AND THE DEEPENING LOW TO THE EAST ALLOWING FOR FRESH TRADE WIND FLOW BY MID WEEK. ALTIMETER DATA FROM SEVERAL HOURS INDICATED SEAS TO 8 FT PERSISTING N OF 28N W OF 130W. THIS IS DUE TO LINGERING NW SWELL IN THE AREA AND IS EXPECTED TO DECAY BELOW 8 FT LATER TONIGHT. $$ CHRISTENSEN