000
AXPZ20 KNHC 201530
TWDEP 

TWDEP 

TROPICAL WEATHER DISCUSSION                                   
NWS NATIONAL HURRICANE CENTER MIAMI FL                      
1605 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1330 UTC.     
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM 09N85W TO 07N93W. THE ITCZ
STRETCHES FROM 07N94W TO 09N107W TO 01N140W. SCATTERED MODERATE
CONVECTION IS FOUND WITHIN 60 NM EITHER SIDE OF A LINE FROM
08N83W TO 05N85W TO 05N88W...FROM 04N TO 08N BETWEEN 94W AND 99W
AND WITHIN 120 NM EITHER SIDE OF A LINE FROM 10N113W TO 06N118W
TO 06N128W.

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

A WEAK SURFACE RIDGE EXTENDS FROM A 1015 MB HIGH NEAR 23N120W TO
17N108W. THE HIGH IS FORECAST TO WEAKEN AND BECOME PART OF THE
SURFACE RIDGE. THE GRADIENT BETWEEN THE RIDGE AND SURFACE
TROUGHING OVER THE SOUTHWESTERN UNITED STATES AND NW SONORA WILL
TIGHTEN EARLY FRI...SUPPORTING FRESH TO STRONG S FLOW ACROSS THE
GULF OF CALIFORNIA N OF 30N. THIS EVENT SILL WIND DOWN ON
SAT...BUT THE GRADIENT SHOULD STILL BE STRONG ENOUGH TO SUPPORT
FRESH WINDS OFF THE BAJA COAST N OF 25N AND E OF 116W. GUIDANCE
SUGGESTS FRESH TO LOCALLY STRONG N DRAINAGE FLOW ACROSS THE GULF
OF TEHUANTEPEC LATE FRI NIGHT UNTIL SAT. 
  
S OF 15N E OF 110W...

NOCTURNAL PULSES OF FRESH E-NE WINDS ARE EXPECTED ACROSS...AND
JUST DOWNSTREAM OF THE GULF OF PAPAGAYO LATE EACH NIGHT THROUGH
SAT. MODERATE N WINDS ARE EXPECTED ACROSS AND DOWNSTREAM OF THE
GULF OF PANAMA EACH NIGHT THROUGH FRI NIGHT.
 
LONG PERIOD CROSS-EQUATORIAL S SWELL IN THE FORM OF 7-8 FT SEAS
WILL SPREAD N ALONG THE EQUATOR BETWEEN 95W-120W THIS EVENING
THROUGH THU NIGHT.
 
ELSEWHERE FROM THE EQUATOR TO 32N E OF 140W...

A DISSIPATING STATIONARY FRONT EXTENDS FROM 30N125W TO 24N129W
TO 20N137W. THE WIND FIELD IN THE VICINITY OF THIS BOUNDARY
CONTINUES TO WEAKEN. COMBINED SEAS OF 8-11 FT WERE OBSERVED IN
0144Z AND 0316Z ALTIMETRY FROM 18N TO 27N BETWEEN 125W AND 139W
PRIMARILY DUE TO MIXED LONG PERIOD S AND NW SWELL. THESE NW
SWELLS WILL PROPAGATE S AND GRADUALLY SUBSIDE BELOW 8 FT BY
TONIGHT. 

ANOTHER ROUND OF NW SWELL WILL BEGIN ARRIVING AT 30N140W LATE
TONIGHT IN ASSOCIATION WITH A COLD FRONT PASSING N OF THE
SURFACE RIDGE. EXPECT SEAS OF 8-11 FT W OF A LINE FROM 30N131W
TO 27N140W LATE FRI. BY THEN...THE NE TRADES ACROSS THE TROPICS
W OF 125W WILL INCREASE TO FRESH AS COMBINED SEAS BUILD TO 8 FT. 
     
$$
MCELROY