000 AXPZ20 KNHC 080241 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC WED OCT 08 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 0230 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION SIMON CENTERED AT 28.1N 115.8W...OR ABOUT 45 MILES W OF PUNTA EUGENIA MEXICO AT 0300 UTC MOVING NE OR 040 DEG AT 06 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1003 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SIMON CONTINUES TO SPIN DOWN WITHIN A BROAD AREA OF OVERCAST STRATOCUMULUS CLOUDS WITH ISOLATED MODERATE AND STRONG CONVECTION OBSERVED WELL NE OF THE CENTER OVER THE GULF OF CALIFORNIA TO THE N OF 30N. THE DEBRIS MOISTURE WILL CONTINUE TO SPREAD NE ACROSS THE SW CONUS. ASSOCIATED SWELLS WILL CONTINUE TO AFFECT PORTIONS OF THE NORTHERN BAJA CALIFORNIA PENINSULA AND SOUTHERN CALIFORNIA TONIGHT...AND THESE SWELLS MAY CAUSE LIFE- THREATENING SURF AND RIP CURRENTS. SIMON IS FORECAST TO WEAKEN TO A 25 KT REMNANT LOW PRESSURE CENTER AROUND SUNRISE ON WED. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. ...TROPICAL LOWS AND WAVES... A TROPICAL WAVE IS ANALYZED N OF 07N ALONG 88.5W AND HAS BEEN PROGRESSING WESTWARD AT 10 KT. SCATTERED MODERATE TO STRONG CONVECTION...WITH FREQUENT LIGHTNING...CONTINUES TO FLARE ALONG THE WAVE AXIS ALONG THE COAST OF EL SALVADOR. A 1011 MB LOW PRESSURE IS EMBEDDED IN THE MONSOON TROUGH AT 13N136.4W WITH SCATTERED MODERATE TO STRONG CONVECTION OBSERVED OVER AND WITHIN 150 NM TO THE N OF THE CENTER. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A 1009 MB LOW PRESSURE IS EMBEDDED IN THE BROAD MONSOON TROUGH OVER THE SW CARIBBEAN NEAR 12N82W. THE MONSOON TROUGH EXTENDS SW FROM THE LOW ACROSS COSTA RICA ALONG 10N TO THE PACIFIC COAST OF COSTA RICA AT 09N85W CONTINUING W THROUGH THE BASE OF A TROPICAL WAVE AT 10N90W THEN SW TO 08N100W...THEN TURNS NW TO 10N112W... THEN SW TO 08N123W...THEN NW TO AN EMBEDDED 1011 MB LOW PRES AT 13N136.5W...WITH THE MONSOON TROUGH THEN CONTINUING SW TO BEYOND 12N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED ALONG THE MONSOON TROUGH WITHIN 120 NM EITHER SIDE OF LINES FROM 07N80W TO 10N92W TO 08N97W...AND FROM 06N99W TO 09N116W TO 07N121W TO 08N132W. SCATTERED MODERATE TO STRONG CONVECTION IS NOTED OVER AND WITHIN 60 NM OF THE COAST OF CENTRAL AMERICA AND MEXICO WITHIN 60 NM FROM 84W TO 104W. ...DISCUSSION... AN UPPER LEVEL CYCLONE IS CENTERED NEAR 33N122W AND HAS AN UPPER TROUGH EXTENDING SW TO 20N130W WITH THE ASSOCIATED SOUTHWESTERLY UPPER FLOW ADVECTING THE DEBRIS MOISTURE FROM THE CYCLONE NE ACROSS THE SW CONUS. A UPPER ANTICYCLONE IS CENTERED AT 22N111W WITH AN UPPER RIDGE EXTENDING SW TO ANOTHER UPPER ANTICYCLONE AT 14N141W. UPPER DIFFLUENCE IS ENHANCING SCATTERED MODERATE CONVECTION WITHIN 90 NM OF A LOW LEVEL TROUGH EXTENDING FROM 09N122W TO 17N116W. THE TROUGH IS MOVING WESTWARD AND WILL MOVE UNDER THE UPPER RIDGE WITH LESS FAVORABLE CONDITIONS FOR CONVECTION ON WED. FURTHER W...UPPER DIFFLUENCE OVER THE E SEMICIRCLE OF THE ANTICYCLONE AT 14N141W IS SUPPORTING THE CONVECTION PREVIOUSLY DESCRIBED NEAR THE 1011 MB SURFACE LOW AT 13N136.5W. THIS FAVORABLE UPPER ENVIRONMENT MAY PERSIST FOR ANOTHER DAY OR SO. THE PREVIOUSLY MENTIONED LOW PRESSURE OVER THE SW CARIBBEAN IS EXPECTED TO MOVE ACROSS CENTRAL AMERICA ON WED EMERGING IN THE EPAC NEAR 11N87W ON WED NIGHT. THE LOW WILL THEN MOVE NW TO NEAR 11N88W ON THU...NEAR 11N90W ON FRI...NEAR 11N91W ON SAT AND NEAR 13N92W ON SUN. CONDITIONS WILL BECOME MORE FAVORABLE FOR STRENGTHENING LATE IN THE PERIOD. GULF OF TEHUANTEPEC...THE NORTHERLY NOCTURNAL DRAINAGE FLOW ACROSS THE GULF OF TEHUANTEPEC IS EXPECTED TO INCREASE TO 20-25 KT LATE WED NIGHT THROUGH LATE MORNING ON THU WITH SEAS BUILDING TO 8 FT. THE NORTHERLY DRAINAGE FLOW IS LIKELY TO INCREASE OVER THE UPCOMING WEEKEND IF THE LOW PRESSURE ALREADY DISCUSSED TO THE SE OF TEHUANTEPEC STRENGTHENS. $$ NELSON