000 AXPZ20 KNHC 201550 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC WED MAY 20 2015 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 1530 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH IS CURRENTLY NOT EVIDENT ACROSS THE REGION. THE ITCZ AXIS EXTENDS FROM 08N90W TO 07N113W...THEN RESUMES FROM 08N116W TO 08N127W TO 07N135W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM N AND 240 NM S OF THE AXIS BETWEEN 111W-113W...AND ALSO BETWEEN 116W-130W. SIMILAR CONVECTION IS WITHIN 240 NM S OF THE ITCZ BETWEEN 130W-135W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM N AND 240 NM S OF THE ITCZ BETWEEN 90W-95W. ...DISCUSSION... UPPER LEVELS... A DEEP LAYER TROUGH STRETCHES FROM A CYCLONIC CIRCULATION WELL N OF THE AREA SSW TO 32N126W TO NEAR 23N128W. TO THE S OF THE TROUGH BROAD ANTICYCLONIC COVERS THE AREA WITH THE ANTICYCLONE CENTER AT 09N140W. A JET STREAM BRANCH ENTERS THE DISCUSSION AREA AT 21N140W...AND ROUNDS THE BASE OF THE TROUGH TO 21N126W ...AND NE TO 24N118W AND TO OVER NW MEXICO. BROKEN HIGH CLOUDS STREAMING ENE ARE SEEN WITHIN 140 NM SE OF THE JET STREAM TO THE E OF 120W...AND WITHIN 180 NM S OF THE JET W OF 120W. SIMILAR SCATTERED CLOUDS STREAMING NEWD ARE WITHIN 120 NM OF LINE FROM 32N119W TO 28N130W. WATER VAPOR IMAGERY SHOWS POCKETS OF MODERATE SUBSIDENCE FILTERING INTO THE BASE OF THE TROUGH WITH THE RESULTANT STABLE AIR MASS MAINTAINING MAINLY BROKEN STRATOCUMLUS CLOUDS MOVING IN A SW DIRECTION TO THE N OF 19N AND W OF 126W. OVER THE FAR EASTERN PORTION OF THE AREA AN UPPER LOW HAS DROPPED SOUTHWARD TO NEAR 02N94W. CONVECTIVE ACTIVITY IN CLUSTERS OF MOSTLY SCATTERED MODERATE INTENSITY REMAINS ACTIVE TO THE E AND NE OF THIS LOW N OF ABOUT 02N. THE LOW IS FORECAST TO CONTINUE TO MOVE SSE THROUGH SAT WHILE WEAKENING AS THE DEEP LAYER TROUGH LIFTS NEWD AND THE AFOREMENTIONED BROAD RIDGING TO ITS W EXPANDS IN AN EWD FASHION. AT THE SURFACE... A NEARLY STATIONARY WEAK 1019 MB HIGH CENTER IS ANALYZED AT 26N125W WITH A RIDGE EXTENDING SE TO NEAR 19N112W. HIGH PRES COVERS THE AREA N OF 18N AND W OF 116W. A WEAK TROUGH EXTENDS FROM 12N112W TO 04N115W...WHILE ANOTHER TROUGH IS ANALYZED FROM 15N131W TO LOW PRES NEAR 08N136W 1009 MB...AND TO 04N136W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM OF THE FIRST TROUGH FROM 04N TO 08N...WHILE SIMILAR CONVECTION IS NOTED WITHIN 120 NM IN THE NW QUADRANT OF THE LOW NEAR 08N136W. THE PRES GRADIENT BETWEEN THESE FEATURES...AND THE RIDGE TO THEIR N SHOULD ALLOW FOR MODERATE TO FRESH NE TRADES TO PERSIST FROM ABOUT 12N TO 19N W OF 116W THROUGH THE NEXT 48 HRS WITH SEAS IN THE 6-8 FT RANGE. MODELS SUGGEST THAT THE WEAK HIGH AND RIDGE WILL BE REPLACED BY STRONGER HIGH PRES THAT BUILDS IN FROM THE NW BEGINNING ON FRI. THE INDUCED PRES GRADIENT BETWEEN IT AND LOWER PRES E OF BAJA CALIFORNIA SHOULD ALLOW FOR NW 20-25 KT WINDS TO MATERIALIZE ALONG THE W COAST OF THE BAJA CALIFORNIA PENINSULA. WAVEWATCH GUIDANCE PROJECTS SEAS TO BE IN THE RANGE OF 6-7 FT S OF PUNTA EUGENIA BEGINNING SAT. GAP WINDS... GAP WIND FLOW ACROSS AND DOWNWIND OF THE GULF OF PAPAGAYO INCREASED TO NEAR 20 KT LAST NIGHT. NE WINDS THERE ARE FORECAST TO INCREASE TO NEAR 20 KT FRI NIGHT...AND AGAIN ON SAT NIGHT. MARINE EVENTS... A NEW PULSE OF STRONG SOUTHWESTERLY SWELL WILL MOVE ACROSS THE EQUATOR AND INTO THE FORECAST WATERS BEGINNING ON THU...WITH ASSOCIATED WAVE HEIGHTS OF 8-9 FT AND WITH PERIODS OF 15 TO 18 SEC...MAINLY W OF THE GALAPAGOS...THEN REACH THE COASTLINES OF CENTRAL AMERICA AND SOUTHERN MEXICO LATE FRI AND SAT. THESE LONG PERIOD SWELLS ARE FORECAST TO POSSIBLY GENERATE LARGE AND DANGEROUS SURF CONDITIONS ALONG THESE COASTLINES THROUGH THE UPCOMING WEEKEND. $$ AGUIRRE