000
AXPZ20 KNHC 180946
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU APR 18 2013

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0945 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS NW FROM THE COAST OF COLOMBIA AT 
04N77W TO 09N85W TO 03N115W WHERE SCATTEROMETER WINDS INDICATE 
A TRANSITION TO AN ITCZ WHICH CONTINUES NW TO 06N122W THEN 
TURNS SW TO BEYOND 02N140W. AN EMBEDDED N TO S TROUGH IS ANALYZED
FROM 12N120W TO 06N123W. SCATTERED MODERATE TO STRONG CONVECTION
IS NOTED WITHIN 90 NM OF 03N78W. SCATTERED MODERATE ISOLATED
STRONG CONVECTION IS OBSERVED IN CLUSTERS WITHIN 90 NM
OF 04.5N93W AND 05N101W. ISOLATED MODERATE AND STRONG CONVECTION
IS NOTED ELSEWHERE WITHIN 180 NM EITHER SIDE OF A LINE FROM
06N78W TO 04N111W...AND WITHIN 15 NM EITHER SIDE OF A LINE FROM
10N118W TO 11N121W TO 05N130W. 

...DISCUSSION... 
GULF OF TEHUANTEPEC...SOUTHERLY WINDS AT 5 TO 15 KT ARE
EXPECTED ACROSS THE GULF OF TEHUANTEPEC...AND JUST TO THE S OF 
THE GULF THROUGH LATE FRI AFTERNOON. NORTHERLY WINDS WILL SURGE
THROUGH THE CHEVILA PASS ON FRI EVENING...INITIALLY AT 15 TO 20
KT...BUT QUICKLY INCREASE TO MINIMAL GALE FORCE LATE FRI NIGHT
AND CONTINUE THROUGH SUNRISE SAT...WITH SEAS BUILDING TO A MAX
OF 11 FT NEAR 14.5N95W SAT MORNING. THE N WINDS WILL DIMINISH
TO 20 TO 25 KT BY SAT AFTERNOON WITH THE SOUTHERN EXTENT OF 
THESE N TO NE WINDS REACHING 11.5N97W SAT EVENING. LITTLE CHANGE
IS EXPECTED THROUGH SUNRISE SUN...THEN WINDS WILL QUICKLY DIMINISH
TO 15 TO 20 KT BY MID MORNING SUN...AND 10 TO 15 KT BY SUN 
EVENING. THE RESULTANT N SWELL WILL BUILD SEAS TO 8 FT...WITH
THESE CONDITIONS PROPAGATING SW TO NEAR 09N99W LATE SUN WHILE
CONTINUING TO MIX WITH CROSS EQUATORIAL S SWELL AND SUBSIDE BELOW
8 FT LATE SUN NIGHT. 

GULF OF CALIFORNIA...NW WINDS ARE AT 15 TO 20 KT ACROSS THE
ENTIRE THE GULF OF CALIFORNIA WITH SEAS 3 TO 5 FT. THE 
GRADIENT WILL INCREASE TODAY WITH NW WINDS AT 20 TO 30 KT AND 
SEAS BUILDING 6 TO 8 FT ACROSS THE GULF WATERS FROM 25N TO 28N 
BY THIS EARLY EVENING...BUT EXPECTED TO FURTHER BUILD TO 7 TO 
10 FT LATE TONIGHT. THE GRADIENT WILL RELAX SUPPORTING NW WINDS
AT 15 TO 20 KT ON FRI NIGHT AS SEAS SUBSIDE TO 1 TO 3 FT N OF 
27N AND 3 TO 5 FT S OF 27N. NW FLOW EXPECTED AT 10 TO 15 KT ON
SAT. WINDS WILL BECOME LIGHT AND VARIABLE ACROSS THE ENTIRE GULF
OF CALIFORNIA ON SAT NIGHT INTO EARLY SUN...THEN INCREASE TO 10
TO 15 KT BRIEFLY SUN NIGHT BEFORE DIMINISHING AGAIN ON MON NIGHT.
 
GULF OF PAPAGAYO...ENE WINDS AT 15 TO 20 KT WILL CONTINUE THROUGH 
SUNRISE TODAY THEN DIMINISH TO 5 TO 10 KT THIS AFTERNOON. LIGHT 
AND VARIABLE WINDS ARE EXPECTED EACH AFTERNOON THROUGH LATE
EVENING...WITH THE LATE NIGHT THROUGH SUNRISE ENE DRAINAGE FLOW
AT ONLY 10 TO 15 KT...WITH THIS PATTERN PERSISTING THROUGH MON.

GULF OF PANAMA...LIGHT AND VARIABLE WINDS AT 5 TO 10 KT ARE
EXPECTED THROUGH SUN.

SURFACE HIGH PRESSURE IS ANALYZED NW OF THE AREA WITH A RIDGE 
AXIS EXTENDING SE INTO THE DISCUSSION AREA FROM 32N134W TO 
13N106W. THE GRADIENT IS SUPPORTING N TO NE TO E WINDS AT 15
TO 20 KT ACROSS THE WATERS W OF A LINE FROM THE CENTRAL BAJA
CALIFORNIA PENINSULA TO 05N140W...WITH SEAS 7 TO 8 FT IN MIXED
N SWELL. NE TRADES SW OF THE RIDGE WILL CONTINUE WITH SEAS 
7 TO 8 FT ACROSS THE TROPICAL WATERS FROM 06N TO 18N W OF 122W
ON FRI. THE GRADIENT SW OF THE RIDGE WILL RELAX OVER THE 
WEEKEND WITH SEAS SUBSIDING TO 6 TO 7 FT. WINDS NE OF THE RIDGE
WILL INCREASE TO 15 TO 20 KT ON SAT NIGHT ACROSS THE WATERS N
OF 28N BETWEEN 120W AND 130W.  

NW TO N WINDS AT 15 TO 20 KT...WITH SEAS 5 TO 8 FT IN NW 
SWELL...ARE CURRENTLY OBSERVED ALONG THE W COAST OF THE BAJA
CALIFORNIA PENINSULA TO THE N OF 25N WHILE 10 TO 15 KT WINDS
ARE OBSERVED S OF 25N WITH SEAS OF 4 TO 6 FT. THE GRADIENT
WILL RELAX LATER TODAY SUPPORTING N WINDS AT 10 TO 15 KT 
ALONG THE ENTIRE PACIFIC COAST OF BAJA TONIGHT AND FRI. 
  
$$
NELSON