000
AXPZ20 KNHC 211521
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON APR 21 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 
1500 UTC. 
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
 
AN ILL-DEFINED MONSOON TROUGH EXTENDS FROM 10N85W TO 06N92W. THE 
ITCZ CONTINUES FROM 06N92W TO 06N110W TO 05N140W. CLUSTERS OF 
MODERATE TO ISOLATED STRONG CONVECTION ARE FROM 05N TO 07N E OF 
80W AND FROM 05N TO 08N BETWEEN 82W AND 85W. SCATTERED MODERATE 
CONVECTION IS NOTED ELSEWHERE FROM 04N TO 07N BETWEEN 80W AND 
88W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 
08N TO 11N BETWEEN 105W AND 110W. SCATTERED MODERATE CONVECTION 
CAN BE FOUND FROM 06N TO 09N BETWEEN 120W AND 130W...AND FROM 
02N TO 05N BETWEEN 130W AND 135W.

...DISCUSSION...                                       

ALOFT...AN UPPER LEVEL TROUGH IS MOVING INTO THE FAR NW CORNER 
OF THE DISCUSSION AREA AND NOW EXTENDS FROM 31N135W TO BEYOND 
27N140W. THIS TROUGH SUPPORTS A WEAKENING COLD FRONT WHICH 
CURRENTLY CROSSES 30N140W. THIS FRONT WILL BECOME DIFFUSE TODAY. 
A RIDGE IS AHEAD OF THE UPPER LEVEL TROUGH WITH AXIS ALONG 120W 
COVERING ROUGHLY THE AREA N OF 20N BETWEEN 115W-125W. ANOTHER 
UPPER LEVEL TROUGH EXTENDS ACROSS WESTERN TEXAS INTO NW MEXICO. 
MID TO UPPER LEVEL SUBSIDENCE AND IMPLIED DRY AIR MASS IS NOTED 
ON WATER VAPOR IMAGERY N OF 18N BETWEEN 110N-125W AND FROM 15N-
25N W OF 125W. IN THE DEEP TROPICS AN UPPER LEVEL ANTICYCLONIC 
CIRCULATION IS CENTERED NEAR 7N133W. UPPER LEVEL DIFFLUENCE 
ASSOCIATED WITH THIS FEATURE IS ENHANCING CONVECTION FROM 2N-9N 
BETWEEN 120W-135W. A DIFFLUENT PATTERN ALOFT ASSOCIATED WITH 
ANOTHER RIDGE OVER NORTHERN SOUTH AMERICA IS HELPING TO INDUCE 
CONVECTION SOUTH OF PANAMA...PARTICULARLY N OF 4N E OF 85W.  

A 1033 MB HIGH PRES LOCATED NEAR 35N154W EXTENDS A RIDGE SE 
ACROSS THE FORECAST WATERS TO NEAR 20N110W. TRADE WINDS OF 15-20 
KT ARE NOTED PER SCATTEROMETER DATA ON THE SOUTHERN PERIPHERY OF 
THE RIDGE AND N OF THE ITCZ AXIS WITH SEAS TO 8 FT. THE HIGH 
WILL MOVE TO A POSITION NEAR 34N145W BY 24 HOURS WITH LITTLE 
CHANGE IN THE WEATHER PATTERN ACROSS THE FORECAST REGION. AS 
HIGH PRES CONTINUES TO MOVE EASTWARD OVER THE NEXT 36-48 
HOURS...EXPECT INCREASING NW TO N WINDS WITH BUILDING SEAS TO 
AROUND 11 FT OFF OF NORTHERN BAJA CALIFORNIA...MAINLY N OF 28N E 
OF 123W BY WED MORNING.
 
LONG PERIOD NW SWELLS...WITH A LEADING EDGE PERIOD OF 17-18 
SECONDS...ARE SPREADING SE ACROSS THE N WATERS RAISING SEAS UP 
TO 11 FT N OF 29N BETWEEN 122W AND 128W. THIS SWELL EVENT WILL 
MIX WITH SHORTER PERIOD NE SWELL FROM THE TRADE WIND FLOW TO 
COVER MOST OF THE WATERS W OF 110W BY TUE MORNING. CROSS 
EQUATORIAL SW SWELL DOMINATES THE REMAINDER OF THE FORECAST 
WATERS MAINLY E OF 110W. 

$$
GR