000
AXPZ20 KNHC 150231
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE MAR 15 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED FROM 03N77W 
TO 04N94W TO 06N110W TO 05N125W TO 04N140W. ISOLATED MODERATE 
CONVECTION IS NOTED WITHIN 90 NM EITHER SIDE OF AXIS W OF 115W.  

...DISCUSSION...
ALOFT...A RIDGE FROM THE HAWAIIAN ISLANDS EXTENDS NE TO OVER THE 
NW CORNER OF THE FORECAST AREA. AN UPPER LEVEL TROUGH LIES E OF 
THE RIDGE EXTENDING FROM 30N124W TO BEYOND 18N140W. AN UPPER 
ANTICYCLONE IS CENTERED AT 10N114W WITH AN UPPER RIDGE EXTENDING 
NWD TO NEAR 24N115W. A WIDE BAND OF MID/UPPER LEVEL MOISTURE IS 
NOTED SE OF THE TROUGH AND ON THE NORTHERN PERIPHERY OF THE 
RIDGE CROSSING THE CENTRAL WATERS INTO CENTRAL MEXICO. THE UPPER 
LEVELS ARE VERY DRY S OF 16N E OF 110W SUPPRESSING CONVECTION 
WITH ONLY ISOLATED SHOWERS NEAR THE ITCZ FROM 87W TO 96W.  

ELSEWHERE AT THE SURFACE...A 1026 MB HIGH PRESSURE REMAINS IN 
CONTROL OF THE WEATHER PATTERN ACROSS THE N WATERS WITH A RIDGE 
COVERING ROUGHLY THE AREA N OF 15N W OF 110W. NORTHERLY WINDS 
ARE AT 20 TO 25 KT N OF 25N E OF 122W TO THE WESTERN COAST OF 
BAJA CALIFORNIA PENINSULA DUE TO THE PRES GRADIENT BETWEEN THE 
HIGH AND LOWER PRES OVER MEXICO. SOME SHIP OBSERVATIONS AND THE 
2326 UTC EXPERIMENTAL ASCAT 25KM COASTAL WINDS CORROBORATED 
THESE WIND SPEEDS. WINDS ARE FORECAST TO SLIGHTLY DIMINISH IN 
ABOUT 24 HOURS AS HIGH PRES DRIFTS WWD AND WEAKENS. HOWEVER... 
WINDS ARE FORECAST TO INCREASE AGAIN TO 25 KT IN 48 HOURS AS 
STRONG HIGH PRES LOCATED NW OF AREA EXTENDS A RIDGE EWD TO THE W 
COAST OF BAJA CALIFORNIA. IN ADDITION...THE AERIAL EXTEND AND 
STRENGTH OF THE TRADES WILL ALSO INCREASE IN ABOUT 48 HOURS AS 
PRES GRADIENT TIGHTENS OVER THE FORECAST WATERS.  

REGIONAL WATERS...W OF 110W...WILL CONTINUE TO BE DOMINATED BY 
ADDITIONAL PULSES OF NW SWELL. CURRENTLY...SEAS OF 9 TO 15 FT IN 
NW SWELL CAN BE FOUND NW OF LINE FROM 30N124W TO 20N132W. A NEW 
TRAIN OF LONG PERIOD NW SWELLS WITH SIGNIFICANT WAVE HEIGHTS AS 
HIGH AS 18 FT WILL PUSH INTO THE NW PORTION TUE NIGHT AND WED. 
CROSS EQUATORIAL SW SWELL WITH PERIODS IN THE 13-14 SECOND RANGE 
DOMINATES MUCH OF THE AREA E OF 110W.   
 
GAP WINDS...
GULF OF TEHUANTEPEC...N WINDS WILL FUNNEL THROUGH THE ISTHMUS OF 
TEHUANTEPEC BEGINNING LATE TUE INTO EARLY WED AS HIGH PRES 
BUILDS OVER NE MEXICO. WINDS WILL PULSE TO 25 KT IN THE MORNING 
HOURS WHEN DRAINAGE FLOW THROUGH THE PASS WILL BE AT ITS DIURNAL 
MAXIMUM. SEAS WILL GRADUALLY BUILD TO ABOUT 9 FT OVER THE WATERS 
N OF 13N BETWEEN 94W AND 96W BY WED. 

GULF OF PAPAGAYO...DRAINAGE FLOW OFF THE LANDMASS WILL MAINTAIN 
WINDS AT 20 KT DURING THE EARLY MORNING HOURS FOR THE NEXT FEW 
DAYS.

$$
GR