000
AXPZ20 KNHC 030916
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT MAY 03 2008

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 06N77W TO 05N94W TO 05N125W TO 
04N140W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF 
AXIS BETWEEN 86W AND 95W. SCATTERED MODERATE CONVECTION IS FROM 
9N TO 12N BETWEEN 120W AND 122W.

...DISCUSSION...

W OF 110W...
AN ELONGATED MID TO UPPER TROUGH EXTENDS FROM THE SOUTHERN 
CALIFORNIA COAST THRU A SMALL SCALE LOW NEAR 23N134W TO 22N140W. 
INVERTED UPPER TROUGHING REMAINS ESTABLISHED FARTHER SE WITH AN 
AXIS RUNNING ROUGHLY ALONG 20N128W 6N110W. AN ASSOCIATED SFC 
TROUGH IS DRIFTING W ALONG 128W FROM 5N-11N. WHILE DIFFLUENT SLY 
FLOW TO THE E OF THIS EXTENSIVE TROUGHING IS PRODUCING A LARGE 
AREA OF CLOUDINESS ROUGHLY S OF 28N E OF 124W...EMBEDDED 
CONVECTIVE ACTIVITY IS ISOLATED AT BEST. UPPER RIDGING IS 
BUILDING BEHIND THE TROUGH AIDING IN STABILIZING THE ATMOSPHERE 
ALONG AND TO THE W OF THE TROUGH AXES. HOWEVER...THIS RIDGE WILL 
NOT BUILD MUCH FARTHER E AS GLOBAL MODELS ARE IN VERY GOOD 
AGREEMENT IN SHOWING AMPLIFICATION OF THE TROUGH AND THEN 
TRANSITIONING TO A CUT OFF LOW BY MON IN THE VICINITY OF S CALIF.

AT THE SFC...A 1029 MB HIGH PRES SYSTEM IS CENTERED WELL N OF 
THE REGION NEAR 41N142W...INTERRUPTED SLIGHTLY BY A FRONT WHICH 
PASSES JUST N OF THE REGION. THIS LARGE SCALE PATTERN IS 
PRODUCING AN AREA OF 20 KT NE TRADES ON ITS S PERIPHERY AND 
RESIDUAL N WINDS OFF THE COAST OF BAJA. THIS HIGH IS EXPECTED TO 
MEANDER AT A SIMILAR STRENGTH OVER THE NEXT COUPLE OF DAYS SO 
THE WIND REGIMES WILL GENERALLY CHANGE LITTLE. HOWEVER...CURRENT 
NW AND SW SWELL OF 8-10 FT WILL SUBSIDE ALLOWING SEAS TO REDUCE 
TO 8 FT BY SUN. A NLY WIND SURGE AND ASSOCIATED N SWELL MAY 
BEGIN TO FILTER JUST S OF 30N E OF 130W BY MON.

E OF 110W...
A LARGE MID TO UPPER RIDGE CENTERED JUST W OF NICARAGUA 
EXTENDS A RIDGE AXIS NW OVER SOUTHERN MEXICO AND THE WESTERN 
PORTION OF THE GULF OF MEXICO. SWIFT SLY FLOW ALOFT ON THE W 
PERIPHERY OF THE RIDGE IS FUELING CLUSTERS OF CONVECTION FROM 
10N-12N BETWEEN 105W-110W AND SPREADING HIGH LEVEL CLOUDINESS N 
OF THE ITCZ W OF 94W. DIFFLUENCE ALOFT ON THE S SIDE OF THE HIGH 
IS MAINTAINING CONVECTION WITHIN THE ITCZ BETWEEN 86W-95W. A 
QSCAT PASS SHORTLY AFTER 00Z HINTS AT A WEAK SFC LOW NEAR 
7N90W...WHICH IS ALSO LIKELY CONTRIBUTING TO THE CONVECTION 
MENTIONED. GLOBAL MODELS SHOW THE RIDGE STRENGTHENING SLIGHTLY 
AS IT DRIFTS N. THIS MAY HELP FOCUS THE CONVECTIVE ACTIVITY 
SLIGHTLY FARTHER N TOWARD THE SW COAST OF MX AND ADJACENT WATERS 
W OF 95W LATER THIS WEEKEND. 

AT THE SFC...WINDS ARE LIGHT ACROSS MUCH OF THIS REGION AS 
INDICATED BY SEVERAL SHIP REPORTS AND A COUPLE SCATTEROMETER 
PASSES. THE ONLY AREA OF ENHANCED WINDS...NW 15-20 KT...IS NEAR 
THE COAST OF MEXICO FROM 19N-23N AND ALONG THE BAJA COAST 
INFLUENCED BY TROUGHING OVER THE COUNTRY. MEANWHILE...THE 
PERSISTENT SW SWELL TRAIN OF 16-18 SECONDS AND UP TO 6 FT 
AFFECTING THE COAST OF MEXICO AND CENTRAL AMERICA HAS PEAKED AND 
WILL SUBSIDE THROUGH THE REMAINDER OF THE WEEKEND. 

$$
CANGIALOSI