000
AXPZ20 KNHC 290330
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE APR 29 2008

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...
ITCZ AXIS RUNS FROM 02N78W TO 6N94W TO 5N100W TO 6N123W TO 
4N132W TO 3N140W. SCATTERED MODERATE AND EMBEDDED ISOLATED 
STRONG CONVECTION IS WITHIN 60 NM OF THE AXIS BETWEEN 89W-92W 
AND FROM 2N-7N BETWEEN 96W-102W. SCATTERED MODERATE CONVECTION 
IS WITHIN 180 NM OF THE AXIS BETWEEN 121W-128W.

...DISCUSSION...

E OF 115W...
A LATE SEASON STRONG COLD FRONT HAS PUSHED S INTO THE BAY OF 
CAMPECHE WITH A COOL HIGH PRES AIRMASS SURGING S OVER MAINLAND 
MEXICO. THIS SYNOPTIC PATTERN HAS SET OFF GALE CONDITIONS IN THE 
GULF OF TEHUANTEPEC...AS VERIFIED BY A QSCAT PASS SHORTLY AFTER 
00Z. THIS PASS SHOWED A SWATH OF 30-40 KT N TO NE WINDS IN THE 
GAP...WHICH IS SLIGHTLY HIGHER THAN GUIDANCE. NWP MODELS AND 
CLIMATOLOGY SUGGEST THAT THIS EVENT SHOULD BE SHORT LIVED 
..LIKELY FALLING BELOW GALE CRITERIA TOMORROW EVENING. 
THE UPPER SUPPORT FOR THE FRONT...A LARGE SCALE TROUGH...EXTENDS 
ACROSS MEXICO AND REACHES A BASE NEAR 20N110W. UPPER CONFLUENCE 
ALONG AND TO THE W OF THE AXIS IS PROVIDING A VERY SUBSIDENT 
ENVIRONMENT FROM 17N-27N. MOIST SOUTHWEST FLOW ALOFT AHEAD OF 
THE TROUGH IS PROVIDING THE EXHAUST TO SUPPORT AREAS OF 
CONVECTION WITHIN THE ITCZ BETWEEN 88W-102W. OTHERWISE...A PAIR 
OF SW SWELL GROUPS WITH PERIODS AS LONG AS 17 TO 19 SECONDS WILL 
PUSH INTO THE AREA THROUGH MID-LATE WEEK.

W OF 115W...
THE AMPLIFIED MID-UPPER PATTERN IS SHOWING SIGNS OF FLATTENING 
AS A LARGE SCALE TROUGH OVER MUCH OF THE MID-LATITUDE WATERS 
RIDES TO THE N OF A SUBTROPICAL RIDGE POSITIONED ALONG 117W. A 
DIFFLUENT PATTERN LIES OVER THE SW PORTION OF THE AREA 
...ASSOCIATED WITH BROAD TROUGHING...SPREADING A FAIR AMOUNT OF 
CLOUDINESS NWD S OF 22N W OF 122W. CONVECTION HAS INCREASED AND 
EXPANDED SLIGHTLY IN THIS DIFFLUENT AREA AND THIS OVERALL 
PULSING OF CONVECTION IS LIKELY TO CONTINUE THROUGH TOMORROW AS 
THE UPPER PATTERN CHANGES LITTLE. A 1032 MB SFC HIGH NEAR 
38N151W IS SHIFTING E IN RESPONSE TO A STORM SYSTEM TO ITS 
W. AS IT DOES SO...N TO NW WINDS WILL STRENGTHEN SLIGHTLY AND 
EXPAND E TO THE N BAJA COAST BY MIDWEEK WITH ASSOCIATED N TO NW 
SWELL BUILDING SEAS TO 10-12 FT OVER THE FAR N WATERS. THIS SFC 
PATTERN WILL ALSO EXPAND THE 20 KT NE TRADES TOMORROW AND WED. 
MEANWHILE...LONG PERIOD SW SWELL WILL CONVERGE WITH NW SWELL AND 
THE AFOREMENTIONED PRODUCED N TO NE WIND WAVES TO CREATE 
CONFUSED SEA CONDITIONS W OF 130W TOMORROW AND WED.

$$
CANGIALOSI