000
AXPZ20 KNHC 182120
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC SAT APR 18 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              

ITCZ AXIS EXTENDS FROM 04N102W TO 02N113W TO 05N135W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION FROM 06N TO 12N BETWEEN 131W 
AND 137W.

...DISCUSSION... 

E OF 120W...A WEAK PRESSURE PATTERN CONTINUES ACROSS THE REGION. 
RECENT SHIP OBS AND SCATTEROMETER SATELLITE DATA INDICATE MAINLY 
LIGHT TO GENTLE WINDS. ALTIMETER DATA IS SHOWING WAVE HEIGHTS TO 
7 FT W OF THE GALAPAGOS ISLANDS FROM SOUTHERLY SWELL. ELSEWHERE 
SEAS ARE GENERALLY 4-5 FT. DIVERGENCE ALOFT IS ENHANCING MODEST 
CONVECTION ALONG A TROUGH EXTENDING FROM 07N95W TO 05N101W. 
PREVIOUS SCAT DATA SHOWED 15-20 KT SOUTHERLY CROSS-EQUATORIAL 
FLOW CONVERGING INTO NEARLY CALM WINDS TO PRODUCE SHOWERS AND 
THUNDERSTORMS WITHIN 120 NM OF A LINE FROM 00N97W TO 00N105W.

W OF 120W...A LARGE AREA OF ACTIVE CONVECTION CONTINUES FROM 05N-
12N W OF 130W...LARGELY DUE TO LOW LEVEL TRADE WIND CONVERGENCE 
AND DIVERGENT FLOW ALOFT BETWEEN A SHARP UPPER TROUGH NW OF AREA 
AND A BROAD UPPER RIDGE CENTERED NEAR 10N123W. A SURFACE TROUGH 
ALONG 137W IS NEARLY STATIONARY. FRESH TRADE WINDS PERSIST N OF 
THE CONVERGENCE ZONE AND S OF A MODERATELY STRONG SUBTROPICAL 
RIDGE. LONG PERIOD NW SWELL CONTINUES TO PROPAGATE INTO THE 
REGION. ALTIMETER DATA SHOW 8-9 FT SEAS FROM 10N-20N. FOLLOWING 
ECWAVE GUIDANCE...WHICH IS MORE INDICATIVE OF ENSEMBLE MEANS 
INDICATING 8 FT SWELL WILL PERSIST INTO EARLY MON...WHILE THE 
MWW3 DECAYS MOST OF THE SWELL TO LESS THAN 8 FT BY EARLY SUN.

$$
MUNDELL