000 AXPZ20 KNHC 030251 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC THU JUL 03 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 0045 UTC. ...SPECIAL FEATURES... TROPICAL STORM DOUGLAS IS CENTERED NEAR 20.2N 116.3W...OR ABOUT ABOUT 725 KM W-SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA AT 03/0300 UTC MOVING N-NW OR 330 DEGREES AT 2 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. SCATTERED MODERATE CONVECTION WAS WITHIN 150 NM E SEMICIRCLE AND 45 NM W SEMICIRCLE OF CENTER. DOUGLAS IS EXPECTED TO BECOME A TROPICAL DEPRESSION THURSDAY MORNING AND DEGENERATE INTO A REMNANT LOW BY FRIDAY MORNING. PLEASE SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 07N78W TO 07N83W TO 10N95W TO 07N110W THEN CONTINUES FROM 14N118W TO 11N130W. THE ITCZ AXIS WAS ANALYZED FROM 09N136W TO LOW PRES NEAR 08N138W 1010 MB TO 07N140W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS WITHIN 300 NM S OF THE AXIS BETWEEN 85W AND 91W. SCATTERED MODERATE CONVECTION WAS WITHIN 210 NM N AND 240 NM S OF THE AXIS BETWEEN 94W AND 110W. ...DISCUSSION... AN UPPER ANTICYCLONE CENTERED NEAR 13N116W EXTENDS RIDGE AXES NORTHEASTWARD TOWARD MAZATLAN AND SOUTHEASTWARD TO NEAR 05N94W. BETWEEN THE TWO RIDGE AXES...20-30 KT N WINDS ALOFT PASS OVER THE OFFSHORE WATERS OF CENTRAL MEXICO. THIS WIND SHEAR HAS TAKEN ITS TOLL ON POST-TROPICAL CYCLONE ELIDA NEAR 17N102W 1011 MB. CONVECTION NEAR ELIDA IS NOT VERY WELL ORGANIZED...WITH SCATTERED MODERATE CONVECTION NOTED IN THIS AREA FROM 17N TO 22N BETWEEN 102W AND 109W. CONVECTION IS MORE ACTIVE NEAR THE SOUTHERN RIDGE AXIS. MOISTURE CONVERGED ALONG THE MONSOON TROUGH IS BEING LIFTED BY THE DIFFLUENCE ALOFT ASSOCIATED WITH THE RIDGE. THIS IS ENHANCING THE PRECIPITATION PRIMARILY BETWEEN 94W AND 110W ALONG THE MONSOON TROUGH. SOUTHERLY FLOW ON THE EAST SIDE OF DOUGLAS HAS TRANSPORTED LOW LEVEL MOISTURE NORTHWARD INTO THE GULF OF CALIFORNIA. THIS SURGE OF MOISTURE IS EXPECTED TO BRING PRECIPITABLE WATER VALUES OVER TWO INCHES TO 30N BY THU MORNING. THIS MOISTURE IS HELPING TO FUEL EVENING THUNDERSTORMS OVER THE SIERRA MADRE OCCIDENTAL AND BAJA CALIFORNIA SUR...WITH SCATTERED MODERATE CONVECTION NOTED IN THE GULF OF CALIFORNIA FROM 23N TO 26N. AT THE SURFACE...A 1025 MB SUBTROPICAL HIGH WAS ANALYZED NEAR 37N144W AND EXTENDS A RIDGE THROUGH 32N124W TO N OF TROPICAL STORM DOUGLAS NEAR 26N115W. TRADE WINDS ARE GENERALLY A GENTLE TO MODERATE BREEZE S OF THE RIDGE AXIS. LONG PERIOD CROSS EQUATORIAL SOUTHERLY SWELL WILL CONTINUE TO PROPAGATE N ACROSS THE TROPICAL WATERS E OF 130W...BUILDING SEAS UP TO 11 FT. THE LEADING EDGE OF THE NEXT SOUTHERLY SWELL TRAIN WILL CROSS THE EQUATOR TONIGHT WITH PERIODS IN THE 20-22 SECOND RANGE. THIS SWELL EVENT WILL REACH THE COAST OF COSTA RICA AND WESTERN PANAMA THU EVENING AND COVER THE ENTIRE COAST S OF 28N BY FRI EVENING...BRINGING ROUGH SURF CONDITIONS. GAP WINDS...WINDS WILL APPROACH 25 KT DURING THE OVERNIGHT HOURS LATE THU NIGHT INTO FRI MORNING IN BOTH THE GULF OF TEHUANTEPEC AND THE GULF OF PAPAGAYO AS HIGH PRESSURE BUILDS OVER THE NORTHERN GULF OF MEXICO. THIS WILL INCREASE THE PRESSURE GRADIENT BETWEEN THE HIGH TO THE NORTH AND THE MONSOON TROUGH TO THE SOUTH...FORCING THE WINDS TO FUNNEL THROUGH THESE GAPS IN THE TERRAIN. $$ SCHAUER