000 AXPZ20 KNHC 110945 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC WED MAY 11 2016 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 0945 UTC. ...INTERTROPICAL CONVERGENCE ZONE... A MONSOON TROUGH EXTENDS W FROM THE PACIFIC COAST OF COSTA RICA AT 10N86W TO A WEAK 1010 MB LOW PRES NEAR 07N90W...THEN THE MONSOON TROUGH TURNS NW TO 13N104W...THEN SW THROUGH A 1010 MB LOW PRES AT 12N109W TO ANOTHER 1010 MB LOW PRES AT 08N118W. SCATTEROMETER WINDS INDICATE AN ITCZ FORMS AT 08N118W AND CONTINUES SW TO 05N134W TO BEYOND 05N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 120 NM SW SEMICIRCLE OF A WEAK QUASI-STATIONARY LOW PRES AT 07N90W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 210 NM NE QUADRANT AND 90 SE QUADRANT OF A LOW PRES AT 12N109W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 90 NM SW QUADRANT OF LOW PRES AT 08N118W WHICH IS EXPECTED TO DISSIPATE WITHIN 24 HOURS. ISOLATED MODERATE TO STRONG CONVECTION IS NOTED ELSEWHERE WITHIN 120 NM EITHER SIDE OF LINES FROM 03N83W TO 08N96W TO 06N100W TO 10N103W...AND FROM 07N123W TO 09N128W TO 06N140W. ...DISCUSSION... N OF 15N E OF 120W... A N-S SURFACE TROUGH WILL PERSIST ACROSS THE BAJA PENINSULA THIS WEEK...BECOMING MOST PRONOUNCED DURING AFTERNOON AND EARLY EVENING DURING PEAK HEATING. GUIDANCE IS SUGGESTING THAT THE SOUTHERLY FLOW WILL INCREASE TO 20 TO 25 KT ACROSS THE GULF WATERS FROM 29.5N TO 31N W OF 113W ON SAT NIGHT. MODERATE NW WINDS ARE EXPECTED TO DEVELOP IN THE LATE AFTERNOONS WITHIN 120 NM W OF THE BAJA PENINSULA AND PERSIST THROUGH SUNRISE EACH DAY THIS WEEK. THE PRESSURE GRADIENT IS EXPECTED TO TIGHTEN ON SAT WITH MODERATE TO FRESH NW FLOW DEVELOPING ACROSS THE EPAC WATERS FROM 27-32N E OF 120W. A NW TO SE SURFACE RIDGE WILL MEANDER ACROSS THE TROPICAL WATERS ROUGHLY FROM NEAR 22N120W TO BEYOND 15N98W THROUGH THE UPCOMING WEEKEND. LIGHT TO GENTLE ANTICYCLONIC FLOW AROUND THE QUASI- STATIONARY RIDGE IS EXPECTED ELSEWHERE ACROSS THE OPEN EPAC WATERS W OF 97W THIS WEEK...EXCEPT MODERATE-FRESH N-NE FLOW EXPECTED S OF 17N BETWEEN 105-120W IN RESPONSE TO A TROPICAL LOW PRESSURE SYSTEM S OF THE AREA. LIGHT ONSHORE FLOW IS EXPECTED ACROSS THE GULF OF TEHUANTEPEC DURING THE DAYLIGHT HOURS AND LIGHT OFFSHORE FLOW IS EXPECTED DURING THE OVERNIGHT HOURS THROUGH THU EVENING. GUIDANCE IS SUGGESTING THAT STRONG NORTHERLY DRAINAGE FLOW WILL DEVELOP LATE THU NIGHT...WITH A MORE SIGNIFICANT EVENT EXPECTED ON FRI NIGHT. COMBINED SEAS OF 3-6 FT ARE CURRENTLY OBSERVED ACROSS THE OPEN PAC WATERS W OF 100W IN MIXING LONG-PERIOD CROSS EQUATORIAL S SWELL AND LONG PERIOD NW SWELL. S OF 15N E OF 110W... MODERATE E NOCTURNAL DRAINAGE FLOW EXPECTED ACROSS...AND JUST N OF THE GULF OF PAPAGAYO TONIGHT...WITH SEAS BUILDING TO 6 FT. THE GRADIENT WILL TIGHTEN A LITTLE ON THU WITH FRESH DRAINAGE FLOW EXPECTED EACH NIGHT THE REMAINDER OF THIS WEEK BEGINNING ON THU NIGHT. SCATTEROMETER WINDS DETECT A 1010 MB LOW ALONG THE MONSOON TROUGH NEAR 07N90W ACCOMPANIED BY LIGHT WINDS. THE LOW IS EXPECTED TO MOVE W AND GRADUALLY LOSE IDENTITY BY FRI. A TROPICAL LOW IS ANALYZED NEAR 12N109W AND IS ESTIMATED AT 1009 MB. THE LOW IS FORECAST TO DRIFT SLIGHTLY SW TO NEAR 11N110W TONIGHT AND NEAR 09N115W ON THU NIGHT. MODERATE-FRESH N-NE WINDS ARE EXPECTED ACROSS THE NW SEMICIRCLE OF THE LOW THROUGH THU THEN THE ASSOCIATED CONDITIONS WILL SHIFT W OF 110W. OTHERWISE...GENTLE NORTHERLY FLOW IS EXPECTED N OF THE MONSOON TROUGH...AND MODERATE S FLOW EXPECTED S OF THE TROUGH AXIS. ELSEWHERE FROM THE EQUATOR TO 32N E OF 140W... A RIDGE EXTENDS SE FROM NEAR 32N132W TO BEYOND 22N120W. FRESH NE WINDS ARE NOTED ACROSS THE TROPICS BETWEEN THE RIDGE AND THE ITCZ ALL TO THE W OF 115W...WITH SEAS OF 7-8 FT CURRENTLY OBSERVED ACROSS THE TROPICAL WATERS FROM 07-15N BETWEEN 115- 140W. THE GRADIENT WILL RELAX TODAY WITH THE SEAS SUBSIDING TO A MAX OF 7 FT. A 1010 MB LOW PRES IS NOTED ALONG THE MONSOON TROUGH NEAR 08N118W. THIS LOW IS EXPECTED TO LOSE IDENTITY WITHIN 24 HOURS. A 1009 MB TROPICAL LOW CURRENTLY NEAR 12N109W IS FORECAST TO MOVE SLOWLY W TO NEAR 11N110W TONIGHT AND NEAR 09N115W ON THU NIGHT. GUIDANCE NOW SUGGESTS THE CYCLONIC CIRCULATION WILL CONTINUE AROUND A WEAK LOW SHIFTING WSW TO NEAR 09N118W LATE FRI. THE PRESSURE GRADIENT WILL SUPPORT FRESH N-NE WINDS WITHIN 300 NM OVER THE W SEMICIRCLE OF THE LOW CENTER. A COLD FRONT EXTENDS FROM 32N137W TO 29N140W AND IS ACCOMPANIED BY A FRESH S-SW-NW WIND SHIFT S OF 32N. A SURFACE HIGH WILL SHIFT S TO NEAR 29N127W TONIGHT AND BLOCK THE EASTWARD PROGRESSION OF THE COLD FRONT WHICH IS EXPECTED TO STALL FROM ABOUT 32N132W TO 26N140W EARLY FRI. $$ NELSON