000
AXPZ20 KNHC 050321
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON MAR 05 2012
 
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 0230 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

THE MONSOON TROUGH IS CURRENTLY NOT EVIDENT ACROSS THE E 
PACIFIC. ITCZ AXIS REMAINS S OF THE EQUATOR E OF 90W...CROSSES 
THE EQUATOR AT 92W TO 01.5N101W THEN CROSSES INTO THE SOUTHERN 
HEMISPHERE AGAIN ALONG 107W...CROSSES THE EQUATOR AGAIN NEAR 
114W TO 03.5N120W TO THE EQUATOR NEAR 140W. 

...DISCUSSION...

MIDDLE TO UPPER LEVEL ANTICYCLONIC FLOW PREVAILS ACROSS THE AREA 
EAST OF 120W...AS RIDGING ALONG 100W YESTERDAY HAS SHIFTED WWD 
ACROSS MEXICO AND INTO THE EPAC IN ADVANCE OF A SHORTWAVE 
TROUGH...WHICH CURRENTLY EXTENDS FROM 32N128W TO 25N124W TO 
19N130W. AT LOWER LEVELS...THE EPAC HIGH PRES RIDGE CONTINUES 
ANCHORED BY A WEAKENING 1026 MB HIGH NEAR 39N131W EXTENDING SE 
TO NEAR 22N114W. FRESH TRADEWINDS ARE FOUND S OF THE HIGH... 
ROUGHLY FROM 05N TO 12N W OF 130W...AND WILL DIMINISH IN 
INTENSITY AND AREAL EXTENT THROUGH MONDAY EVENING AS THE SURFACE 
HIGH WEAKENS AND SHIFTS SOUTHWARD. THE RIDGE WILL RE-BUILD BY 
THE MIDDLE OF THE WEEK AS THE DEEP LAYER RIDGE BECOMES 
RE-ESTABLISHED ACROSS THE NORTH PACIFIC ALONG 140W. THIS IN TURN 
WILL FRESHEN THE TRADEWIND FLOW FROM 05N TO 20N W OF 120W BY 
WEDNESDAY. A BROAD AREA OF NORTHWESTERLY SWELL MIXING WITH 
FRESHER NORTHEASTERLY TRADEWIND SWELL WILL DECAY GRADUALLY 
THROUGH WEDNESDAY.

GAP WINDS...

GULF OF CALIFORNIA...THE PRES GRADIENT BETWEEN THE HIGH OFFSHORE 
OF NORTHERN CALIFORNIA AND LOWER PRESSURE ALONG THE SIERRA MADRE 
OCCIDENTALES OF W MEXICO HAS WEAKENED SLIGHTLY AND STRONG NWLY 
WIND FLOW THROUGH THE ENTIRE LENGTH OF THE GULF OF CALIFORNIA 
HAS WEAKENED TO 20 TO 25 KT THIS EVENING...WITH PEAK SEAS 8 TO 9 
FT EXPECTED S OF 26N. THESE WINDS ARE EXPECTED TO GRADUALLY 
DIMINISH BELOW 20 KT BY MON MORNING AS THE PRES GRADIENT LOOSENS 
BETWEEN THESE WEAKENING FEATURES.

GULF OF TEHUANTEPEC...A COOL AIR MASS BEHIND A GULF OF MEXICO 
COLD FRONT CONTINUES TO DRIVE VERY STRONG GAP WIND FLOW THROUGH 
THE CHIVELA PASS THIS EVENING...THEN THROUGH AND DOWNSTREAM OF 
THE GULF OF TEHUANTEPEC. NO MARINE OBSERVATIONS HAVE BEEN 
RECEIVED TO CORROBORATE MODEL FORECASTS...AND IT IS ASSUMED THAT 
A SMALL AREA OF MAX WINDS 45-50 KT CONTINUE THROUGH THIS GULF 
THIS EVENING...WITH A LARGE AREA OF GALES EXTENDING WELL 
DOWNSTREAM...AND WITH SEAS AS HIGH AS 18-19 FT. A LONG PLUME OF 
WINDS OF 20 TO 30 KT WILL CONTINUE TO EXTEND FARTHER SOUTH AND 
SOUTHWESTWARD...REACHING AS FAR AS 10N100W BY TUESDAY. 
NORTHEASTERLY SWELL WILL BUILD WITHIN THIS PLUME...MIXING WITH 
LONGER PERIOD NORTHWESTERLY SWELL THROUGH THE MIDDLE OF THE 
WEEK. THE WINDS WILL DIMINISH TO STRONG GALES MONDAY MORNING... 
AND THEN TO LESS THAN GALE FORCE ON WEDNESDAY EVENING. 

GULF OF PAPAGAYO...NELY WIND THROUGH THE GULF OF PAPAGAYO WILL 
INCREASE TO 20 TO 25 KT OVERNIGHT...AND THEN 20 TO 30 KT MONDAY 
MORNING. THESE WINDS WILL SPREAD SOUTHWESTWARD AND DOWNWIND OF 
THE GULF BEYOND 450 NM BY MIDDAY MONDAY...WITH SEAS BUILDING TO 
12 FT. THIS WILL OCCUR AS THE PRESSURE GRADIENT BEHIND THE GULF 
OF MEXICO COLD FRONT EXPANDS ACROSS CENTRAL AMERICA TONIGHT AND 
MONDAY.  

$$
STRIPLING