000 AXPZ20 KNHC 020928 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC WED JUL 02 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 0900 UTC. ...SPECIAL FEATURES... TROPICAL STORM DOUGLAS IS CENTERED NEAR 19.6N 116.0W...OR ABOUT ABOUT 395 NM...730 KM WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA AT 02/0900 UTC MOVING NW OR 325 DEGREES AT 03 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1001 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. DOUGLAS IS LIKELY TO BECOME A TROPICAL DEPRESSION BY TONIGHT OR EARLY THURSDAY AS IT MOVES OVER COLDER WATER. NUMEROUS MODERATE TO STRONG CONVECTION IS WITHIN 90 NM NE SEMICIRCLE OF CENTER. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 60 NM SW SEMICIRCLE. PLEASE SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. ELIDA HAS WEAKENED AND NOW IS A REMNANT LOW. AT 02/0900 UTC...IT IS CENTERED NEAR 16.9N 103.0W...OR ABOUT ABOUT 145 NM...270 KM SSE OF MANZANILLO MEXICO...MOVING SE OR 135 DEGREES AT 3 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB. MAXIMUM SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 KT. THE REMNANT LOW IS EXPECTED TO DISSIPATE IN A COUPLE OF DAYS. NO DEEP CONVECTION IS ASSOCIATED WITH THIS SYSTEM. PLEASE SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH AXIS EXTENDS FROM 07N78W TO LOW PRES NEAR 08N89W 1009 MB TO 09N95W TO 07N110W THEN RESUMES SW OF DOUGLAS FROM 12N120W TO 09N130W. ITCZ AXIS STRETCHES FROM 09N130W TO 08N135W. SCATTERED MODERATE TO STRONG CONVECTION IS ON EITHER SIDE OF THE MONSOON TROUGH COVERING THE AREA FROM 05N TO 11N BETWEEN 91W AND 109W. ...DISCUSSION... AN UPPER LEVEL ANTICYCLONE CENTERED NEAR 15N112W EXTENDS A RIDGE NORTHEASTWARD INTO THE SOUTHERN GULF OF CALIFORNIA. THIS SYSTEM IS PRODUCING 20-30 KT NW WINDS ALOFT PARALLEL TO THE COAST OF MEXICO AND OVER TROPICAL DEPRESSION ELIDA. AS A RESULT...ELIDA WAS DOWNGRADED TO A REMNANT LOW AT 02/0900 UTC AND THE LAST ADVISORY WAS ISSUED BY THE NATIONAL HURRICANE CENTER ON THIS SYSTEM. A DIFFLUENT PATTERN ALOFT BETWEEN THIS ANTICYCLONE AND AN UPPER LEVEL TROUGH THAT CROSSES THE ISTHMUS OF TEHUANTEPEC IS HELPING TO INDUCE CONVECTION NEAR THE MONSOON TROUGH BETWEEN 91W AND 109W. THE ANTICYCLONE IS FORECAST TO SHIFT WESTWARD. AN UPPER-LEVEL LOW IS SPINNING NEAR 18N134W. MAINLY A ZONAL FLOW IS NOTED OVER THE NW CORNER OF THE FORECAST REGION. MODERATE TO STRONG SUBSIDENCE AND IMPLIED DRY AIR MASS COVERS THE AREA NW OF A LINE FROM 27N113W TO 16N130W TO 12N140W. SOUTHERLY FLOW ON THE EAST SIDE OF DOUGLAS IS TRANSPORTING LOW LEVEL MOISTURE NORTHWARD INTO THE SOUTHERN BAJA CALIFORNIA AND GULF OF CALIFORNIA. THIS SURGE OF MOISTURE SHOULD HELP FUEL AFTERNOON AND EVENING THUNDERSTORMS OVER THE SIERRA MADRE OCCIDENTAL AS WAS PREVIOUSLY OBSERVED ON SATELLITE IMAGERY. AT THE SURFACE...HIGH PRES LOCATED WELL NW OF THE AREA NEAR 39N150W EXTENDS A RIDGE SE ACROSS THE N WATERS MAINLY N OF 20N W OF 125W. TRADE WINDS ARE GENERALLY A GENTLE TO MODERATE BREEZE S OF THE RIDGE AXIS. A SURFACE TROUGH IS WITHIN THE ITCZ AND EXTENDS FROM 10N134W TO 05N140W. ISOLATED MODERATE CONVECTION IS WITHIN 60 NM EITHER SIDE OF TROUGH FROM 05N TO 08N. THIS TROUGH WILL MOVE WESTWARD AND AWAY FROM THE FORECAST REGION IN ABOUT 24- 36 HOURS. LONG PERIOD CROSS EQUATORIAL SOUTHERLY SWELL WILL CONTINUE TO PROPAGATE N ACROSS THE TROPICAL WATERS E OF 125W 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 BY THU EVENING...AND THE COAST OF MEXICO AND NORTHERN CENTRAL AMERICA THU NIGHT...BRINGING ROUGH SURF CONDITIONS TO THOSE COASTS. $$ GR