000 AXPZ20 KNHC 190959 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC TUE MAY 19 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A MONSOONAL CIRCULATION IS NOT PRESENTLY EVIDENT ACROSS THE REGION. THE ITCZ AXIS EXTENDS FROM 02.5N88W TO 08N100W TO 08.5N110W TO 05N115W TO 09.5N121W TO BEYOND 03.5N140W. SCATTERED MODERATE TO STRONG CONVECTION NOTED N OF 13N BETWEEN 90W AND 94.5W. ISOLATED TO SCATTERED MODERATE CONVECTION NOTED WITHIN 60 NM S OF TROUGH FROM 01S88W TO 0.5S100W. ISOLATED TO SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 330 NM N AND 210 NM S OF AXIS BETWEEN 90W AND 107W. SCATTERED MODERATE TO STRONG CONVECTION NOTED WITHIN 240 NM EITHER SIDE OF AXIS W OF 110W. ...DISCUSSION... DEEP LAYERED TROUGHING PERSISTS ACROSS THE NE PACIFIC THIS MORNING N OF 28N AND E OF 140W AND INTO THE PACIFIC NW U.S. TO THE S OF THIS...AN UPPER LEVEL RIDGE PREVAILS N OF THE EQUATOR BETWEEN 110W AND 160W...WHERE ACTIVE CONVECTION CONTINUES TO PULSE...AS DESCRIBED ABOVE. A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM FROM THE FAR NW CARIB SW ACROSS CENTRAL AMERICA AND INTO THE EPAC E OF 110W...WHERE AN UPPER CYCLONE OS DEVELOPING NEAR 08N96W. AT THE SURFACE...AN OLD COLD FRONT HAS WEAKENED AND BECOME NEARLY STATIONARY FROM NEAR 30N127W TO 23N140W. WHILE A SUBTLE WIND SHIFT IS PRESENT ON RECENT SCATTEROMETER DATA...WINDS ARE GENERALLY 15 KT OR LESS ON EITHER SIDE OF THE FRONT...AND SEAS TO THE NW OF THE FRONT REMAIN IN THE 5 TO 6 FT RANGE AND ARE EXPECTED TO SUBSIDE SLIGHTLY THROUGH WEDNESDAY. OTHERWISE...THE REMAINDER OF THE WATERS N OF 12N ARE UNDER THE INFLUENCE OF A WEAK SURFACE RIDGE ANCHORED BY A 1023 MB HIGH CENTERED NEAR 29N124W WITH AXIS EXTENDING SE TO 19N109W WITH MODERATE TO FRESH NE TRADES OCCURRING TO THE SOUTH AND SOUTHWEST OF THE RIDGE BETWEEN ABOUT 10N AND 22N. SEAS ACROSS THIS AREA ARE IN THE RANGE OF 5 TO 7 FT...EXCEPT NEAR 8 FT FROM 11.5N TO 19N BETWEEN 121W AND 133W...AND FROM 06N TO 10N W OF 131W...WHERE ZONES OF SOLID 20 KT TRADES ARE MIXING WITH FADING NW SWELL. TO THE E OF THE HIGH...THE PRESSURE GRADIENT BETWEEN THE HIGH AND LOWER PRESSURE ACROSS THE GULF OF CALIFORNIA AND NORTHWESTERN MEXICO IS GENERATING A MODERATE NORTHWESTERLY BREEZE ALONG MOST OF THE PACIFIC COASTAL WATERS OF THE BAJA CALIFORNIA PENINSULA. THIS PATTERN IS EXPECTED TO REMAIN GENERALLY UNCHANGED FOR THE NEXT 48 HOURS...AND ALLOW FOR DIURNAL HEATING ALONG THE BAJA PENINSULA TO ENHANCE THE NW WINDS TO AROUND 20 KT WITH ISOLATED AREAS TO 25 KT WITHIN 60 NM OF THE COAST THIS AFTERNOON AND AGAIN WEDNESDAY AFTERNOON...WHEN SEAS WILL BUILD TO 7-8 FT. WITHIN THE DEEP TROPICS...SEVERAL EASTERLY WAVES ARE PROPAGATING WESTWARD THROUGH THE REGION W OF 90W...ONE ALONG ABOUT 108W... ANOTHER ALONG ABOUT 123W AND A THIRD ALONG 130-131W. THE MOST ACTIVE CONVECTION ASSOCIATED WITH THESE WAVES IS OCCURRING UNDERNEATH THE UPPER RIDGE W OF 110W. THESE WAVES WILL CONTINUE TO MOVE W AT NEAR 10 KT OVER THE NEXT FEW DAYS...WITH FRESH NE TRADES AROUND 20 KT PREVAILING TO THE N AND NE OF THE WESTERN- MOST TWO WAVES. ACROSS THE EASTERN PORTION OF THE DEEP TROPICS...THE MONSOON TROUGH IS NOT EVIDENT WITH GENERALLY LIGHT TO GENTLE WINDS OCCURRING FROM THE EQUATOR TO 10N E OF 100W. THE EXCEPTION TO THIS IS THE PULSING GAP WIND EVENT OCCURRING ACROSS THE GULF OF PAPAGAYO AND DOWNWIND TO TO NEAR 95W...WHERE ELY WINDS OF 15-20 KT PREVAIL...WITH SEAS 5 TO 7 FT. NOCTURNAL DRAINAGE FLOW IS PRESENTLY ENHANCING THIS FLOW ACROSS THE GULF OF PAPAGAYO AND DOWNWIND TO 88W...WITH STRONG ENE TRADES 20-25 KT...AND SEAS BUILDING 6-8 FT. WINDS THERE ARE EXPECTED TO DIMINISH TO 15 TO 20 KT BY AFTERNOON...AND THEN PULSE AGAIN EARLY WEDNESDAY MORNING TO AROUND 20 KT WITH SEAS BUILDING TO 6-7 FT. LOOKING AHEAD...ANOTHER STRONG SOUTHERN HEMISPHERIC SW SWELL WILL MOVE INTO THE REGIONAL WATERS LATE IN THE WEEK. SEAS WILL BUILD TO 8 FT AND GREATER ALONG THE EQUATORIAL WATERS BY THU MORNING. THIS PULSE OF LONG PERIOD SWELL IS EXPECTED TO REACH THE COASTLINES OF CENTRAL AMERICA BY LATE FRI...AND WILL GENERATE LARGE AND DANGEROUS SURF ALONG THE PACIFIC COASTLINES THROUGH THE WEEKEND. $$ STRIPLING