000 AXPZ20 KNHC 031449 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1415 UTC. ...SPECIAL FEATURES... TROPICAL STORM DOUGLAS IS CENTERED NEAR 20.6N 116.6W...OR ABOUT 400 NM W-SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA AT 03/1500 UTC MOVING NW OR 320 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 ISOLATED STRONG CONVECTION IS WITHIN 120 NM OF CENTER OVER E QUADRANT. DOUGLAS IS EXPECTED TO WEAKEN TO A TROPICAL DEPRESSION LATER TODAY. PLEASE SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. ...TROPICAL WAVE... TROPICAL WAVE EXTENDS FROM 13N95W TO INLAND OVER S MEXICO NEAR 16N95W MOVING W 20 KT OVER THE PAST 24 HOURS. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM 14N TO INLAND OVER S MEXICO BETWEEN 93W AND 97W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH AXIS FROM 08N78W TO 09N91W TO 10N103W TO 10N108W TO 08N114W THEN CONTINUES FROM 13N118W TO 10N124W TO 09N132W. ITCZ AXIS FROM 10N136W TO BEYOND 09N140W. SCATTERED MODERATE STRONG CONVECTION IS WITHIN 150 NM S OF MONSOON TROUGH BETWEEN 80W AND 85W AND N OF 11N OVER EL SALVADOR BETWEEN 88W AND 92W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS WITHIN 60 NM OF 3N BETWEEN 80W AND 85W...FROM 07N TO 11N BETWEEN 100W AND 104W...FROM 04N-12N BETWEEN 107W AND 116W. ...DISCUSSION... AN UPPER RIDGE IS TO THE W OF DOUGLAS NEAR 21N121W. A CUT-OFF UPPER LOW IS FURTHER W NEAR 17N136W WITH AN UPPER TROUGH EXTENDING W TO BEYOND 16N140W. SATELLITE WATER VAPOR IMAGERY SHOWS STRONG SUBSIDENCE WITH DRY STABLE AIR N OF 16N W OF 118W. THIS DRY AIR IS IMPEDING THE DEVELOPMENT OF CONVECTION TO THE W OF T.S. DOUGLAS. W TO SW FLOW ALOFT IS NOTED OVER THIS SAME AREA TO AN UPPER TROUGH THAT EXTENDS FROM THE N GULF OF CALIFORNIA NEAR 31N113W OVER THE BAJA OF CALIFORNIA NEAR 27N113W TO 24N110W. AN UPPER RIDGE EXTENDS INLAND OVER MEXICO PROVIDING UPPER LEVEL DIFFLUENCE BETWEEN THESE UPPER FEATURES TO GENERATE SCATTERED MODERATE CONVECTION N OF 20N E OF 110W AND CONTINUING OVER THE GULF OF CALIFORNIA. AN INVERTED UPPER TROUGH IS FROM 9N92W TO JUST E OF THE GULF OF TEHUANTEPEC NEAR 15N93W. THIS UPPER TROUGH COUPLED WITH THE TROPICAL WAVE IS PRODUCING THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVE. AT THE SURFACE...A 1010 MB LOW...REMNANTS OF ELIDA...IS CENTERED NEAR 17N103W PRODUCING ISOLATED MODERATE CONVECTION WITHIN 60 NM OF CENTER. A SURFACE RIDGE EXTENDS THROUGH 32N133W TO 29N116W. GENTLE TO MODERATE TRADE WINDS PERSIST S OF THE RIDGE AND N OF THE MONSOON TROUGH. A WEAK SURFACE TROUGH IS ANALYZED FROM 15N131W TO 08N134W. ISOLATED SHOWERS ARE WITHIN 120 NM OF THE TROUGH AXIS. LONG PERIOD CROSS EQUATORIAL SOUTHERLY SWELL WILL CONTINUE TO PROPAGATE N ACROSS THE TROPICAL WATERS...BUILDING SEAS UP TO 11 FT S OF THE EQUATOR. THE LEADING EDGE OF THE THIS SOUTHERLY SWELL TRAIN HAS CROSSED THE EQUATOR WITH PERIODS IN THE 20-22 SECOND RANGE. THIS SWELL EVENT WILL REACH THE COAST OF COSTA RICA AND WESTERN PANAMA THIS EVENING AND COVER THE ENTIRE COAST S OF 30N AND THE SOUTHERN PORTION OF THE GULF OF CALIFORNIA BY FRI EVENING... BRINGING ROUGH SURF CONDITIONS. GAP WINDS...WINDS WILL APPROACH 25 KT DURING THE OVERNIGHT HOURS LATE TONIGHT INTO FRI MORNING...THEN AGAIN LATE FRI NIGHT INTO SAT IN BOTH THE GULF OF TEHUANTEPEC AND THE GULF OF PAPAGAYO. HIGH PRESSURE IS FORECAST TO BUILD OVER THE GULF OF MEXICO INCREASING THE PRES GRADIENT ACROSS THE REGION AND WITH NIGHTTIME DRAINAGE IS CREATING THE WINDS AND SEAS OVER THE GULF OF TEHUANTEPEC. THE STRONG BREEZES IN THE CARIBBEAN AND THE NIGHTTIME DRAINAGE IS PRODUCING THE WINDS AND SEAS IN THE GULF OF PAPAGAYO. $$ PAW