000
AXPZ20 KNHC 250331
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI FEB 25 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 A 1009 
MB LOW PRES NEAR 05N77W TO 01N100W TO 03N120W TO 06N132W TO 
05N140W. NO SIGNIFICANT CONVECTION.

...DISCUSSION...

AN ANTICYCLONE ALOFT SW OF THE GULF OF TEHUANTEPEC NEAR 13N98W 
WILL MIGRATE NE TO THE TEHUANTEPEC COAST THROUGH SAT MORNING. 
STRONG SUBSIDENCE ACCOMPANIES THE ANTICYCLONE AS EVIDENCED IN 
RECENT WATER VAPOR IMAGERY. AS A RESULT...ONLY LOW-TOPPED 
SHOWERS ARE SEEN OVER CENTRAL AMERICA AND ADJACENT WATERS. AN 
UPPER TROUGH LIES TO THE W OF THE ANTICYLONE FROM NW MEXICO TO 
NEAR 23N124W THEN CONTINUES S AND SE TO THE EQUATOR AT 120W. A 
NARROW BAND OF MID TO UPPER LEVEL MOISTURE IS BEING TRANSPORTED 
NORTHEASTWARD FROM NEAR THE BASE OF THE TROUGH TO ACROSS LAS 
MARIAS ISLANDS INTO NE MEXICO. THE TROUGH ALOFT WILL PUSH 
EASTWARD THROUGH NW MEXICO AND THE SW CONUS TONIGHT AS THE 
NORTHERN STREAM FLOW BECOMES MORE ZONAL. MID/UPPER LEVEL 
MOISTURE IS ON INCREASE ACROSS THE WESTERN WATERS AHEAD OF A 
CUT-OFF LOW LOCATED JUST SOUTH OF THE HAWAIIAN ISLANDS. 

AT THE SURFACE...HIGH PRES CENTERED NEAR 32N132W EXTENDS A RIDGE 
OVER MUCH OF THE FORECAST AREA. THIS FEATURE WILL MOVE INTO THE 
NW WATERS THIS MORNING AS A NEW COLD FRONT APPROACHES FROM THE 
NORTH. THE STRENGTHENING PRES GRADIENT BETWEEN THIS RIDGING AND 
DEEPENING LOW PRES OVER NE MEXICO WILL ALLOW 20 KT NW TO N WINDS 
ON EITHER SIDE OF THE SOUTHERN BAJA PENINSULA THROUGH TONIGHT. 
AT THE SAME TIME...WINDS WILL INCREASE TO 20 KT N OF 26N AND E 
OF 116W AND ACROSS THE N PORTION OF THE GULF OF CALIFORNIA BY 
SAT NIGHT AS THE COLD FRONT ENTERS THE FAR N WATERS. A NEW 
POSITIVELY TILTED NORTHERN STREAM TROUGH WILL SUPPORT THIS COLD 
FRONT. NW TO N WINDS IN THE 20 TO 30 KT RANGE AND BUILDING SEAS 
OF UP TO 15 FT IN NW SWELL ARE EXPECTED IN THE WAKE OF THE FRONT 
SAT NIGHT. IN ADDITION...WINDS ARE FORECAST TO INCREASE OVER THE 
N PORTION OF THE GULF OF CALIFORNIA AHEAD OF THE FRONT SAT NIGHT.

THE PRES GRADIENT BETWEEN THE ANOMALOUSLY SOUTHERN ITCZ AND THE 
RIDGING N OF IT IS PRODUCING FRESH TO STRONG TRADE WINDS AS FAR 
S AS 05N IN WESTERN WATERS ACCORDING TO AN EARLIER ASCAT PASS.  
THIS AREA OF TRADES IS EXPECTED TO REMAIN RELATIVELY UNCHANGED 
UNTIL MIDDAY TODAY WHEN THE NEW NORTHERN STREAM TROUGH AND 
ASSOCIATED COLD FRONT BEGIN TO WEAKEN THE SURFACE RIDGE TO THE 
NORTH. 

GAP WINDS...
EXPECT ELY WINDS NEAR 20 KT TO PULSE UP AND DOWN THROUGH THE 
GULF OF PAPAGAYO AND THEN DOWNSTREAM TO NEAR 88W DURING THE NEXT 
FEW DAYS. 

$$
GR