000
AXPZ20 KNHC 202148
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                      
2205 UTC WED APR 20 2016 

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
2145 UTC.     
  
...INTERTROPICAL CONVERGENCE ZONE...

A TROUGH EXTENDS OFF THE PACIFIC COAST OF COSTA RICA AT 09N84W TO
07N93W WHERE SCATTEROMETER WINDS INDICATE AN ITCZ FORMS AND CONTINUES
W TO 08N100W TO 08N120W...THEN TURNS SW TO BEYOND 05N140W. SCATTERED
MODERATE ISOLATED STRONG CONVECTION IS NOTED OVER AND TO THE S OF THE
TROUGH FROM 03.5N82.5W TO 09N BETWEEN 84-91W. SIMILAR CONVECTION
IS OBSERVED N OF THE ITCZ WITHIN 150 NM EITHER SIDE OF A LINE FROM
09N101W TO 10N113W...AND OVER AND TO THE S OF THE ITCZ WITHIN 120 NM
EITHER SIDE OF A LINE FROM 05N111W TO 06N124W TO 08N127W TO 06N131W.   

...DISCUSSION...
  
N OF 15N E OF 120W... 

A WEAK SURFACE RIDGE IS MEANDERING FROM NEAR 18N120W TO BEYOND
15N107W. A WEAK TROUGH IS OBSERVED N OF THE RIDGE FROM 25N118W
TO 32N116W AND IS EXPECTED TO GRADUALLY SHIFT E REACHING OVER
THE NORTHERN BAJA PENINSULA ON FRI. THE PRESSURE GRADIENT WILL
TIGHTEN AND SUPPORT FRESH NW WINDS ACROSS THE WATERS N OF 28N
WITHIN 150 NM W OF THE BAJA PENINSULA BEGINNING LATE FRI...AND
EXPANDING OUT TO 240 NM ON SAT. THE GRADIENT WILL FURTHER
TIGHTEN ON SAT NIGHT WITH STRONG NW WINDS...AND SEAS 10-15
FT...ACROSS THE WATERS FROM 29-32N BETWEEN 118-125W ON SUN AND
MON...WITH THE GRADIENT THEN RELAXING ON TUE INTO WED. THESE
STRONG NW WINDS WILL SEND NW SWELL S WITH SEAS OF 8-11 FT
EXPECTED ACROSS THE WATERS N OF 22N ON MON BEFORE BEGINNING TO
SUBSIDE. FRESH SOUTHERLY FLOW IS EXPECTED ACROSS THE GULF OF
CALIFORNIA TO THE N OF 30N ON FRI NIGHT. GUIDANCE SUGGESTS FRESH
TO LOCALLY STRONG NORTHERLY DRAINAGE FLOW ACROSS THE GULF OF
TEHUANTEPEC LATE FRI NIGHT. 
  
S OF 15N E OF 110W...

NOCTURNAL PULSES OF FRESH ENE WINDS ARE EXPECTED ACROSS...AND
JUST DOWNSTREAM OF THE GULF OF PAPAGAYO TONIGHT AND AGAIN ON THU
NIGHT. MODERATE N WINDS ARE EXPECTED ACROSS AND DOWNSTREAM OF
THE GULF OF PANAMA EACH NIGHT THROUGH THU NIGHT. 
  
ELSEWHERE FROM THE EQUATOR TO 32N E OF 140W...

THE FRONTS ARE DISSIPATING OVER THE SUBTROPICS. SOME REMNANT
SWELL IN THE FORM OF 8-10 FT SEAS CONTINUE FROM 15-25N BETWEEN
131-140W BUT SHOULD SUBSIDE BELOW 8 FT TONIGHT. ANOTHER ROUND OF
NW SWELLS WILL ARRIVE AT 30N140W TONIGHT IN ASSOCIATION WITH A
COLD FRONT SWEEPING E ACROSS THE DISCUSSION WATERS N OF 30N BUT
ONLY ACCOMPANIED BY A 15-20 KT SW-W-NW WIND SHIFT. EXPECT SEAS
OF 8-11 FT W OF A LINE FROM 32N128W TO 26N140W EARLY FRI...AND W
OF A LINE FROM 29N120W TO 17N140W ON SAT. 

NE TRADES ACROSS THE TROPICS W OF 120W WILL STRENGTHEN TO FRESH
WITH COMBINED SEAS BUILDING TO 8 FT ON THU NIGHT AND 9 FT ON FRI
NIGHT. 

SEE AREA N OF 15N E OF 120W FOR DISCUSSION ON STRONG WINDS NEAR
30N120W ON SAT NIGHT.
     
$$
NELSON