000
AXPZ20 KNHC 210228
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                      
0405 UTC THU APR 21 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0215 UTC.     
  
...INTERTROPICAL CONVERGENCE ZONE...

A TROUGH EXTENDS OFF THE PACIFIC COAST OF COSTA RICA AT 08N83W
TO 06N92W WHERE SCATTEROMETER WINDS INDICATE AN ITCZ FORMS AND
CONTINUES W TO 07N110W...THEN TURNS SW TO 04N126W...THEN W TO
BEYOND 05N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS
OBSERVED WITHIN 120 NM OF THE TROUGH AND ALSO OVER AND TO THE N
OF THE ITCZ WITHIN 150 NM EITHER SIDE OF A LINE FROM 11N104W TO
04N125W. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 90 NM OF
LINE FROM 10N122W TO 08N128W AND IS ASSOCIATED WITH A TROUGH
EXTENDING N FROM 05.5N129W TO 11N129.5W.
 
...DISCUSSION...
  
N OF 15N E OF 120W... 

A WEAK SURFACE RIDGE WILL MEANDER FROM NEAR 18N120W TO BEYOND
15N105W INTO THE UPCOMING WEEKEND. A WEAK TROUGH IS OBSERVED N
OF THE RIDGE FROM 27N120W TO 32N115W...AND IS EXPECTED TO
GRADUALLY SHIFT E REACHING OVER THE NORTHERN BAJA PENINSULA ON
FRI. THE PRESSURE GRADIENT WILL TIGHTEN THU NIGHT INTO FRI...AND
SUPPORT FRESH NW WINDS ACROSS THE PACIFIC WATERS FROM 28-32N
WITHIN 150 NM W OF THE BAJA PENINSULA BEGINNING LATE FRI...AND
THEN EXPANDING WESTWARD 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 FROM 22-29N 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 NEXT 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 BEGINNING ON SAT NIGHT.
     
$$
NELSON