000
AXPZ20 KNHC 040956
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU MAR 04 2010

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 
0945 UTC.

...ITCZ...
THE ITCZ AXIS IS ALONG 04N77W TO 06N90W TO 03N110W TO 05N125W TO 
03N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 120 NM N OF 
THE AXIS BETWEEN 90W AND 105W...AND WITHIN 180 NM EITHER SIDE OF 
THE AXIS BETWEEN 110W AND 125W.

...DISCUSSION...
A BROAD BUT SHEARED UPPER-LEVEL TROUGH REMAINS OVER THE NW 
PORTION OF THE DISCUSSION AREA GENERALLY N OF 18N W OF 125W. 
SATELLITE DERIVED WINDS INDICATED A 100-130 KT JET STREAM 
ROUNDING THE BASE OF THE TROUGH TURNING NE ACROSS N-CENTRAL BAJA 
CALIFORNIA AND NORTHERN MEXICO INTO SOUTH TEXAS AND THE GULF OF 
MEXICO. THIS JET WAS TRANSPORTING COPIOUS AMOUNT OF MID AND UPPER
LEVEL MOISTURE ACROSS NORTHERN MEXICO. 

IN THE DEEP TROPICS...AN EAST TO WEST UPPER LEVEL RIDGE EXTENDS 
FROM COLOMBIA ACROSS PANAMA AND COSTA RICA TO NEAR 9N95W. THIS 
RIDGE ALSO COVERS MOST OF CENTRAL AMERICA. AN UPPER LEVEL 
CYCLONIC CIRCULATION EMBEDDED WITHIN AN UPPER TROUGH WAS LOCATED 
NEAR 3N105W. S TO SW UPPER LEVEL WINDS N OF THE RIDGE AND E OF 
THE CIRCULATION ARE TRANSPORTING SOME UPPER LEVEL MOISTURE 
ACROSS SOUTHERN MEXICO AND NORTHERN CENTRAL AMERICA. AN UPPER 
LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 8N115W DOMINATES 
THE MAJORITY OF THE SW PORTION OF THE DISCUSSION AREA. A 
DIFFLUENT PATTERN ALOFT ASSOCIATED WITH THIS FEATURE IS 
ENHANCING CONVECTION ALONG THE ITCZ PARTICULARLY BETWEEN 110W 
AND 125W. A SURFACE TROUGH EMBEDDED WITHIN THE ITCZ IS ANALYZED 
IN THIS AREA ALONG 125W FROM 4N TO 9N. 

AT THE SURFACE A COLD FRONT ENTERED THE DISCUSSION AREA NEAR 
30N122W AND CONTINUED TO 28N137W. THIS FRONT WAS CROSSING INTO A 
RIDGE OF HIGH PRESSURE WHICH DOMINATED THE AREA N OF 15N AND W 
OF 110W. THE GRADIENT S OF THE RIDGE AND THE ITCZ RESULTED IN A 
BROAD SWATH OF NE TO E TRADES OF 20 TO 25 KT. A 0626 UTC HIGH 
RESOLUTION ASCAT PASS VERIFIED THE EXISTENCE OF THE TRADE WINDS
WHICH WERE CONFINED TO AN AREA FROM 6N TO 20N W OF 120W. LITTLE 
CHANGE IN THE AREA OF TRADES IS EXPECTED OVER THE NEXT 48 HOURS 
AS HIGH PRESSURE CONTINUES TO BUILD EWD. AS THE HIGH BUILDS 
EWD...THE PRES GRADIENT BETWEEN THE HIGH AND LOWER PRES OVER 
MEXICO WILL RESULT IN NW WINDS OF 20 KT WITHIN 90 NM OF THE 
COAST OF N BAJA CALIFORNIA PENINSULA DURING THE NEXT COUPLE OF 
DAYS.   

A TRAIN OF LONG PERIOD...17-18 SECONDS...SWELLS IS SPREADING SE 
ACROSS THE FORECAST AREA WITH SEA HEIGHTS OF UP TO 14 FT. THIS 
SWELL WILL CONTINUE TO PROPAGATE SE WITH OVERALL SEA HEIGHTS 
SLOWLY DECREASING. 

GAP WINDS...
WINDS IN THE GULF OF TEHUANTEPEC CONTINUE AT 20 TO 25 KT AND 
WERE CONFIRMED BY AN EARLIER SHIP REPORT FROM NEAR 14N94W 
OF N WINDS OF 20 KT AND SEAS TO 10 FT. THESE ARE EXPECTED TO 
PERSIST FOR ANOTHER 36 HOURS BEFORE DROPPING BELOW 20 KT. 

THE EDGE OF AN 0302 UTC HIGH RESOLUTION ASCAT PASS INDICATED 
NE WINDS OF 20 KT IN THE GULF OF PAPAGAYO. THESE WINDS ARE 
FORECAST TO INCREASE TO 20 TO 25 KT WITHIN THE NEXT 24 HOURS AND 
PERSIST THROUGH THE NEXT FEW DAYS AS HIGH PRESSURE BUILDS 
SOUTHWARD ACROSS CENTRAL AMERICA. THIS WEATHER PATTERN WILL ALSO 
PRODUCE AN INCREASE IN WINDS AND SEAS ACROSS THE GULF OF PANAMA 
BEGINNING IN ABOUT 24 HOURS. WINDS OF 20 KT AND SEAS TO 8 FT ARE 
EXPECTED N OF 5N BETWEEN 79W AND 81W.   

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
COBB