000 AXPZ20 KNHC 041450 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC FRI JUL 04 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 21.6N 118.1W...OR ABOUT 460 NM W OF THE SOUTHERN TIP OF BAJA CALIFORNIA AT 04/1500 UTC MOVING NW OR 310 DEGREES AT 5 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. ISOLATED MODERATE CONVECTION IS FROM 20N TO 22N BETWEEN 116W AND 117W. DOUGLAS IS EXPECTED TO WEAKEN AGAIN TO A TROPICAL DEPRESSION THEN DEGENERATE INTO A REMNANT LOW DURING THE NEXT DAY OR SO. PLEASE SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 99W N OF 13N TO OVER MEXICO MOVING W 15 TO 20 KT OVER THE PAST 24 HOURS. NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE IS ALONG ABOUT 92W N OF 10N EXTENDING ACROSS S MEXICO MOVING W 15 KT OVER THE PAST 24 HOURS. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS N OF 12N TO COAST OF MEXICO BETWEEN 92W AND 95W. THIS CONVECTION IS BEING ENHANCED BY UPPER LEVEL DIFFLUNCE. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH EXTENDS FROM 08N78W TO 07N84W TO 09N98W TO 10N105W TO 12N109W THEN RESUMES 15N120W TO 12N125W TO 10N134W. ITCZ EXTENDS FROM 10N134W TO BEYOND 10N140W. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 04N TO MONSOON TROUGH E OF 82W TO COAST OF COLOMBIA AND WITHIN 120 NM N OF MONSOON TROUGH BETWEEN 87W AND 95W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 03N TO 13N BETWEEN 97W TO 114W. ...DISCUSSION... A 1024 MB SUBTROPICAL HIGH WAS CENTERED NEAR 34N137W AND EXTENDS A WEAK RIDGE S-SE TO NEAR 17N127W. AN UPPER TROUGH OVER NW WATERS HAS DISRUPTED THE DEEP-LAYER RIDGING OVER THE AREA...WEAKENING THE RIDGING AT THE SURFACE. THIS UPPER TROUGH IS EXPECTED TO PINCH OFF A LOW THAT WILL LINGER OVER THE AREA FOR THE NEXT FEW DAYS. THE PRESSURE GRADIENT BETWEEN THE SURFACE HIGH AND THE MONSOON TROUGH/ITCZ IS ONLY SUFFICIENT ENOUGH TO SUPPORT GENTLE TO MODERATE TRADE WINDS S OF 25N. AN UPPER RIDGE JUST INLAND OVER MEXICO BETWEEN THE GULF OF CALIFORNIA AND THE SIERRA MADRE OCCIDENTAL MOUNTAINS IS PROVIDING DIFFLUENCE ALOFT TO GENERATE CLUSTERS OF SCATTERED MODERATE CONVECTION WITHIN 120 NM ALONG THE COAST OF MEXICO BETWEEN BAHIA DE BANDERAS AND MAZATILAN CONTINUING OVER THE GULF OF CALIFORNIA S OF 28N. A WEAK INVERTED UPPER TROUGH EXTENDS ALONG 98W N OF 11N TO INLAND OVER MEXICO. ANOTHER UPPER RIDGE ANCHORED OVER CENTRAL AMERICA IS PROVIDING DIFFLUENCE ALOFT TO ENHANCE THE CONVECTION ASSOCIATED WITH THE EASTERN MOST TROPICAL WAVE THE LEADING EDGE OF THE NEXT CROSS-EQUATORIAL SOUTHERLY SWELL EVENT IS PRESENTLY TO THE COASTS FROM PANAMA TO SOUTHERN MEXICO AND THE ENTRANCE TO THE GULF OF CALIFORNIA...WITH WAVE PERIODS IN THE 20-22 SECOND RANGE. THESE SWELLS COULD CREATE LARGE BREAKING WAVES ALONG THE BEACHES AND REEF LINES WITH DANGEROUS SURF CONDITIONS AND STRONG RIP CURRENTS. GAP WINDS... GULF OF PAPAGAYO...THE ATLANTIC SUBTROPICAL RIDGE IS BUILDING WESTWARD TO THE S OF ATLANTIC HURRICANE ARTHUR...INCREASING THE TRADE WINDS IN THE WESTERN CARIBBEAN. WINDS WILL FUNNEL THROUGH THE GULF OF PAPAGAYO INTO THE PACIFIC AND PULSE TO A FRESH TO STRONG BREEZE WITH THE ASSISTANCE OF NOCTURNAL DRAINAGE FLOW EACH OF THE NEXT FEW NIGHTS. GULF OF TEHUANTEPEC... PRESSURES WILL RISE OVER THE GULF OF MEXICO BEHIND A COLD FRONT CURRENTLY DRAPED ALONG THE N GULF OF MEXICO COAST. THIS COUPLED WITH THE WESTWARD EXPANDING SUBTROPICAL RIDGE WILL INCREASE THE PRESSURE GRADIENT BETWEEN THE HIGH TO THE NORTH AND THE MONSOON TROUGH TO THE E PACIFIC...FORCING N-NE WINDS TO FUNNEL THROUGH THE GULF OF TEHUANTEPEC. WINDS WILL PULSE TO A FRESH TO STRONG BREEZE AS NOCTURNAL DRAINAGE FLOW OFF THE LAND ENHANCES THE WINDS TONIGHT AND SUN NIGHT. $$ PAW