000 AXPZ20 KNHC 050955 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0830 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH IS ALONG 06N90W...TO 1010 MB LOW PRESSURE CENTER THAT IS NEAR 09N112W...TO 08N118W. THE ITCZ CONTINUES FROM 08N118W TO 06N123W TO 06N130W TO 04N138W TO 04N140W. CONVECTIVE PRECIPITATION...SCATTERED STRONG FROM 02N TO 05N BETWEEN 88W AND 93W...FROM 02N TO 04N BETWEEN 98W AND 102W... FROM 05N TO 12N BETWEEN 98W AND 106W...AND FROM 06N TO 10N BETWEEN 110W AND 114W. SCATTERED STRONG FROM 13N TO 15N BETWEEN 110W AND 112W...AND FROM 12N TO 13N BETWEEN 113W AND 114W. ...DISCUSSION... THE GULF OF TEHUANTEPEC...THE FORECAST CALLS FOR NORTHERLY WINDS 20 TO 25 KNOTS AND SEA HEIGHTS FROM 8 FEET TO 10 FEET TO CONTINUE FOR THE NEXT 12 HOURS OR SO. THE SURFACE HIGH PRESSURE THAT IS TO THE NORTH OF THE AREA WEAKENS AND SHIFTS EASTWARD. SCATTERED STRONG CONVECTIVE PRECIPITATION HAS BEEN INCREASING IN COVERAGE DURING THE LAST FEW HOURS AROUND THE 1010 MB LOW PRESSURE CENTER. THE PRECIPITATION COVERS THE PACIFIC OCEAN FROM 08N TO 10N BETWEEN 110W AND 114W. THE CONVECTIVE PRECIPITATION IS BEING SUPPORTED BY A NEGATIVELY TILTED SHORT WAVE TROUGH IN THE MIDDLE LEVELS TO UPPER LEVELS OF THE ATMOSPHERE...TO THE NORTHWEST OF THE SURFACE LOW. THIS FIRST TROUGH IS FORECAST TO LIFT NORTHEASTWARD AND OUT OF THE AREA. IT IS LIKELY THAT ADDITIONAL CONVECTIVE PRECIPITATION MAY FLARE UP TODAY. IT IS POSSIBLE THAT CONVECTIVE PRECIPITATION MAY INCREASE MORE TOMORROW AHEAD OF A MORE SIGNIFICANT LONG WAVE TROUGH...THAT IS APPROACHING THE AREA FROM THE WEST. IT IS HOPED THAT THIS DOES NOT IMPOSE SIGNIFICANT WESTERLY SHEAR OVER THE DEVELOPING CONVECTION. THE CONVECTIVE PRECIPITATION THAT IS JUST TO THE EAST OF THE 1010 MB LOW PRESSURE CENTER IS MORE INTENSE...PERSISTENT AND WIDESPREAD. NO WELL DEFINED LOW LEVEL CENTER IS IN THAT AREA. SCATTERED STRONG CONVECTIVE PRECIPITATION COVERS THE EASTERN PACIFIC OCEAN FROM 05N TO 12N BETWEEN 98W AND 106W. THE PRECIPITATION HAS BEEN PULSING FOR THE PAST SEVERAL DAYS IN THIS AREA. IT IS BEING AIDED BY FAVORABLE JET STREAM DYNAMICS ALOFT. THE COVERAGE OF THE PRECIPITATION HAS INCREASED TODAY WITH THE HELP OF CONSIDERABLE LOW LEVEL CONVERGENCE THAT WAS BEING 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 MORE TO THE SOUTH SHOW LIGHT MOSTLY SE TO S WINDS...POSSIBLY INFLUENCED BY THE DEVELOPING LOW CENTER THAT IS NEAR 09N112W. NO CLEAR MONSOON TROUGH IS TO THE EAST OF 90W AT LEAST FOR THE TIME BEING WITH THIS WIND FLOW PATTERN. THE LATEST GFS MODEL INITIALIZES WELL WITH THE 1010 MB LOW PRESSURE CENTER NEAR 09N1112W. THE GFS MODEL QUICKLY SHOWS THIS LOW CENTER BECOMING ABSORBED INTO A DEEPER LOW CENTER THAT WILL EMERGE OUT OF THE CONVECTIVE MASS THAT IS MORE TO THE 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 LOW CENTER THAT IS MORE TO THE WEST. THE UKMET AND TO A LESSER EXTENT THE ECMWF FAVOR THE DEVELOPMENT OF THE WESTERN LOW CENTER THROUGH THE NEXT 48 HOURS. THE ECMWF COMES MORE INTO AGREEMENT WITH THE GFS POSITION THEREAFTER SHOWING THE EASTERN LOW PRESSURE CENTER TO BE DRIFTING NORTH TO NORTHEAST TOWARD THE CENTRAL COAST OF MEXICO THROUGH MIDDLE OF THE WEEK. THE DIFFERENCES IN INTENSITY BY THAT TIME ARE SIGNIFICANT BETWEEN THE TWO MODELS WITH THE GFS BEING MUCH DEEPER. IT IS LIKELY THAT THIS IS DUE TO THE GFS SHOWING MINIMAL SHEAR ACROSS THE LOW PRESSURE CENTER THAT IS MORE TO THE EAST. THE OFFICIAL FORECAST FOLLOWS THE GFS TREND FOR DEVELOPMENT AND POSITION BUT WITH A NOD TO THE ECMWF IN INTENSITY FOR LATER PERIODS. SCATTEROMETER DATA CONTINUE TO SHOW MODEST TRADE WIND FLOW INTO THE PART OF THE ITCZ THAT IS TO THE SOUTH OF A WEAK SUBTROPICAL RIDGE. THE RIDGE IS EXPECTED TO BUILD DURING THE NEXT COUPLE OF DAYS. THE SURFACE PRESSURE GRADIENT SHOULD TIGHTEN SLIGHTLY BETWEEN THE BUILDING RIDGE TO THE NORTH AND THE DEEPENING LOW PRESSURE CENTER TO THE EAST...ALLOWING FOR FRESH TRADE WIND FLOW BY THE MIDDLE OF THE WEEK. THE LATEST ALTIMETER DATA HAVE BEEN SHOWING 8 FOOT SEA HEIGHTS TO BE PERSISTING TO THE NORTH OF 28N TO THE EAST OF 125W. THE FORECAST IS FOR THE 8 FOOT SEA HEIGHTS TO DECAY IN 6 TO 12 HOURS...AND THEN RE-APPEAR IN ABOUT 48 HOURS IN MORE OR LESS THE SAME AREA. 20 TO 25 KNOT NORTHWESTERLY WIND FLOW WILL BE TO THE NORTH OF 30N IN THE WATERS OFF THE CALIFORNIA COAST AT 48 HOURS. $$ MT