000
AXPZ20 KNHC 160951
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE APR 16 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 SW FROM THE COSTA RICA AND PANAMA 
BORDER TO A 1008 MB LOW PRESSURE CENTER AT 04.5N97W. 
SCATTEROMETER WINDS SUGGEST AN ITCZ FORMS W OF THIS LOW PRESSURE
CENTER AND WIGGLES WNW TO SECOND 1009 LOW PRESSURE CENTER AT 
06.5N115.5W WITH THE ITCZ CONTINUING SW LOSING IDENTITY AT 
02N132W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED 
WITHIN 240 NM AND 180 NM SE SEMICIRCLES OF THE LOW PRESSURE
CENTER AT 06.5N115.5W. SCATTERED MODERATE ISOLATED STRONG
CONVECTION IS NOTED IN A SINGLE CLUSTER WITHIN 30 NM OF 04N81W.
ISOLATED STRONG WITHIN 60 NM EITHER SIDE OF A LINE FROM 07N100W
TO 04N112W...AND WITHIN 30 NM OF 07N134W. SCATTERED MODERATE
ISOLATED STRONG NOTED WITHIN 120 NM EITHER SIDE OF A LINE 
FROM 06N120W TO 06N125W.

...DISCUSSION... 
GULF OF CALIFORNIA...SOUTHERLY 10 TO 15 KT WINDS ARE NOTED
ACROSS THE GULF OF CALIFORNIA WATERS TO THE S OF 29N WHILE 
SOUTHERLY WINDS AT 15 TO 20 KT ARE OBSERVED TO THE N OF 29N
WITH SEAS ESTIMATED TO 5 FT. LITTLE CHANGE IS EXPECTED THROUGH 
THIS AFTERNOON THEN THE GRADIENT WILL RELAX SUPPORTING SOUTHERLY
WINDS AT 10 TO 15 KT IN THE WATERS N OF 29N AND LIGHT 5 TO 10 
KT SOUTHERLY WINDS ELSEWHERE IN THE GULF OF CALIFORNIA. A TROUGH
WILL MOVE INTO THE NORTHERN GULF TONIGHT WITH NW WINDS AT 10
TO 15 KT BEHIND THE TROUGH THROUGH WED MORNING. AS THE TROUGH 
PASSES E OF THE AREA ON WED THE N WINDS WILL INCREASE TO 15 TO 
20 KT AND SPREAD S ACROSS THE ENTIRE GULF OF CALIFORNIA BY WED
EVENING...THEN INCREASE TO 20 TO 25 KT ON THU CONTINUING 
THROUGH FRI. SEAS ARE EXPECTED TO BUILD TO 8 FT IN THE AREAS
OF LONG N TO S FETCH ACROSS THE CENTRAL GULF WATERS. THE
GRADIENT WILL RELAX ON SAT WITH THE NORTHERLY FLOW DIMINISHING
TO 5 TO 10 KT AS THE SEAS SUBSIDE TO 2 TO 3 FT. WINDS WILL
DIMINISH TO LIGHT AND VARIABLE SAT NIGHT BECOMING SOUTHERLY
AGAIN ON SUN.
 
GULF OF TEHUANTEPEC...LIGHT AND VARIABLE WINDS SOUTHERLY WINDS
ARE EXPECTED ACROSS THE GULF OF TEHUANTEPEC THROUGH FRI 
AFTERNOON. NORTHERLY WINDS WILL SURGE THROUGH THE CHEVILA PASS
ON FRI EVENING INITIALLY AT 15 TO 20 KT...BUT QUICKLY INCREASE 
TO 20 TO 30 KT BY SUNRISE SAT. THE N WINDS WILL CONTINUE THROUGH 
SUNRISE SUN BUT PERHAPS AT ONLY 20 TO 25 KT.

GULF OF PAPAGAYO...ENE WINDS AT 10 TO 15 KT WILL INCREASE 
TO 15 TO 20 KT LATE TONIGHT TILL JUST AFTER SUNRISE TUE
MORNING WITH SIMILAR CONDITIONS EXPECTED THROUGH SUNRISE WED. 
THE GRADIENT IS EXPECTED TO RELAX WED AFTERNOON WITH LIGHT 
AND VARIABLE WINDS THROUGH THE REMAINDER OF THE WEEK. 

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 32N138W TO 
15N105W. THE GRADIENT NE OF THE RIDGE AXIS IS SUPPORTING N 
WINDS AT 15 TO 20 KT ACROSS THE WATERS N OF 24N BETWEEN 116W
AND 134W...WITH LONG PERIOD N SWELL RESULTING IN COMBINED SEAS
OF 7 TO 10 IN MIXED N SWELL. NE WINDS CONTINUE AT 10 TO 15 KT 
ACROSS THE TROPICAL WATERS SW OF THE RIDGE. THE AFFECTED AREA
NE OF THE RIDGE WILL SPREAD S TO ALONG 22N BETWEEN 114W AND 
135W BY WED NIGHT. THE N SWELL WILL THEN GRADUALLY SUBSIDE 
ON THU.

W TO NW WINDS AT 10 TO 15 KT...WITH SEAS 4 TO 6 FT IN NW 
SWELL...ARE CURRENTLY OBSERVED ALONG THE ENTIRE W COAST OF
THE BAJA CALIFORNIA PENINSULA. THE NW WINDS WILL INCREASE TO
15 TO 20 KT ACROSS THESE WATERS N OF 28N TODAY AS SEAS BUILD 
TO 5 TO 8 FT. THESE WINDS WILL INCREASE ALONG THE BAJA
PENINSULA S OF 28N ON WED...BUT SEAS ARE EXPECTED TO MAX AT
ONLY 6 FT. THE GRADIENT WILL RELAX ON THU AND FRI AS THE
WINDS CLOCK TO ALMOST DUE N AT 10 TO 15 KT WITH SEAS
SUBSIDING TO 4 TO 5 FT. NW WINDS AT 5 TO 10 KT ARE EXPECTED
ALONG THE ENTIRE PENINSULA ON SAT AND SUN WITH SEAS 3 TO 5
IN NW SWELL.
 
THE TRADES SW OF NEARLY STATIONARY RIDGE WILL INCREASE TO 15
TO 20 KT BUILDING SEAS TO 8 FT ON THU AND FRI. THE EMBEDDED
SURFACE LOW IN THE ITCZ CURRENTLY AT 06.5N115.5W IS EXPECTED
TO SHIFT W AT 5 TO 10 KT THROUGH THE END OF THE WEEK AND THIS 
SHOULD HELP TIGHTEN THE PRESSURE GRADIENT ACROSS THE TROPICS
NW OF THE LOW PRESSURE.

$$
NELSON