000 AXPZ20 KNHC 202213 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC WED JUN 18 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1245 UTC. ...TROPICAL WAVES... A ILL-DEFINED TROPICAL WAVE IS ANALYZED TO THE N OF 12N MOVING W THROUGH THE GULF OF TEHUANTEPEC. AN UPPER ANTICYCLONE IS CENTERED NEAR 10N105W WITH AN UPPER RIDGE EXTENDING NE ACROSS CENTRAL MEXICO AND ALONG THE EASTERN MEXICAN COAST TO A CREST OVER SW LOUISIANA. THIS RESULTS IN UPPER NORTHWESTERLY FLOW ACROSS THE LOWER LEVEL TROPICAL WAVE WHICH IS ADVECTING DRY UPPER AIR SOUTHWARD ACROSS THE EASTERN GULF OF TEHUANTEPEC AND CURRENTLY SUPPRESSING CONVECTION NEAR THE WAVE AXIS. I HAVE RELUCTANCE TO DROP THE WAVE FROM THE SURFACE ANALYSIS AT THIS TIME SINCE THE UPPER LEVELS ARE MOIST FURTHER TO THE W UNDER THE UPPER ANTICYCLONIC ENVELOP. THE WAVE MAY HAVE SOME POTENTIAL TO ENHANCE CONVECTION AGAIN AS IT PASSES ALONG THE PACIFIC COAST OF MEXICO BETWEEN 96-103W OVER THE NEXT COUPLE OF DAYS. ...TROPICAL LOWS... A 1008 MB SURFACE LOW CONTINUES AT 11N109W. AN UPPER ANTICYCLONE IS CENTERED NEAR 10N105W WITH AN UPPER RIDGE EXTENDING W ACROSS THE SURFACE LOW TO A CREST AT 11N112W. THE ASSOCIATED UPPER DIFFLUENCE IS ENHANCING SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 90 NM OF 09.5N112W...WITH ISOLATED MODERATE TO STRONG CONVECTION OBSERVED ELSEWHERE WITHIN 180 NM OF CENTER. CURRENTLY CYCLONIC 15-20 KT WINDS ARE OBSERVED 240 NM OVER THE SE SEMICIRCLE WITH SEAS OF 5-8 FT. THE LOW IS EXPECTED TO MOVE N TO NEAR 12N109W ON SAT AND NEAR 15N109W ON SUN WITH LITTLE CHANGE EXPECTED DURING THAT TIME. LOW PRESSURE CONTINUES NEAR 11N129W AND IS ESTIMATED AT 1008 MB. CURRENTLY SCATTERED MODERATE ISOLATED STRONG CONVECTION IS DECAYING WITHIN 90 NM OF 12N132W. SURFACING RIDGING TO THE N IS SUPPORTING N-NE 15-25 KT WINDS WITHIN 240 NM OVER THE NW SEMICIRCLE OF THE LOW WITH SEAS SEAS OF 6-8 FT. THE LOW IS FORECAST TO MOVE W TO NEAR 11N130W ON SAT AND NEAR 10N131.5W ON SUN WITH LITTLE CHANGE IN WINDS AND SEAS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS SW ALONG THE CARIBBEAN COAST OF COLOMBIA 11N75W TO THE PACIFIC COAST OF COLOMBIA AT 08N78W... THEN TURNS W ACROSS THE SOUTHERN GULF OF PANAMA AND ACROSS THE PACIFIC COAST OF PANAMA TO 08N83W...THEN WIGGLES NW TO 12N105W...THEN SW TO THE EMBEDDED 1008 MB LOW PRESSURE AT 11N109W. THE MONSOON TROUGH CONTINUES W TO 10N115W THEN TURNS NW THROUGH A SECOND 1008 MB EMBEDDED LOW PRESSURE AT 11N129W TO 07.5N133W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO ITCZ WHICH CONTINUES W TO BEYOND 07N140W. EXCEPT AS PREVIOUSLY DESCRIBED NEAR THE TROPICAL WAVES AND TROPICAL LOWS...SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED OVER AND TO THE S OF THE MONSOON TROUGH WITHIN 120 NM EITHER SIDE OF A LINE FROM 06N80W TO 07N84W...AND ALONG THE MONSOON TROUGH WITHIN 240 NM EITHER SIDE OF A LINE FROM 05N89W TO 15N108W AND WITHIN 180 NM EITHER SIDE OF A LINE FROM 08.5N116W TO 11N120W. ...DISCUSSION... AN UPPER CYCLONE IS CENTERED OVER THE MEXICAN COAST AT 24N107W WITH A UPPER TROUGH EXTENDING S TO BASE AT 12N115W. AN AREA OF UPPER DIFFLUENCE IN INDUCED E OF THIS TROUGH WHERE A SMALL UPPER RIDGE HAS BEEN ENHANCING CONVECTION ALONG THE MONSOON TROUGH AND AN EMBEDDED LOW PREVIOUSLY DESCRIBED NEAR 11N109W. STRONG SOUTHERLY UPPER FLOW IS ADVECTING THE DEBRIS MOISTURE N ACROSS MEXICO WITHIN 240 NM EITHER SIDE OF A LINE FROM 13N104W TO 27N100W WHERE THE MOISTURE FANS OUT ACROSS THE S CENTRAL CONUS AND EVENTUALLY TURNS E ACROSS THE SOUTHERN MISSISSIPPI VALLEY. THE SOUTHERLY FLOW E OF THE TROUGH WILL ALSO SHEAR ACROSS THE SURFACE LOW CURRENTLY NEAR 11N109W AS IT MOVES NORTHWARD. AN UPPER ANTICYCLONE NEAR 16N120W HAS AN UPPER RIDGE EXTENDING NE TO A CREST OVER NORTHERN NEW MEXICO. WEAK UPPER DIFFLUENCE ALONG THE SOUTHERN PERIPHERY OF THE ANTICYCLONE IS SOMEWHAT ENHANCING CONVECTION ALONG WESTERN SEGMENT OF THE MONSOON TROUGH AND THE EMBEDDED LOW AT 11N129W. A SURFACE RIDGE EXTENDS FROM 32N133W TO NEAR 15N107W. NW-N WINDS AT 10-15 KT...SEAS OF 3-6 FT IN MIXED NNW AND LONG PERIOD SSE SWELL...ARE OBSERVED N OF RIDGE ACROSS THE SUBTROPICAL WATERS FROM 26-32N E OF 125W TO THE NORTHERN BAJA CALIFORNIA PENINSULA. THE GRADIENT WILL TIGHTEN ON SAT INCREASING THE FLOW TO 15-20 KT ACROSS THE WATERS N OF 30N BETWEEN 120-125W WITH SEAS BUILDING TO 7-8 FT ON SUN NIGHT. GUIDANCE IS SUGGESTING THE GRADIENT WILL RELAX AGAIN LATE SUN WITH SEAS SUBSIDING TO 5-7 FT. LONG PERIOD N AND S SWELL WITH COMBINED SEAS OF 6-9 FT HAS MOVED INTO THE SOUTHERN WATERS TO THE S OF 01N BETWEEN 98-120W. THE SOUTHERLY SWELL IS BEGINNING TO DAMPER WITH SEAS EXPECTED TO SUBSIDE TO 6-7 FT ACROSS THESE SOUTHERN WATERS ON SAT AFTERNOON. $$ NELSON