000
AXPZ20 KNHC 242149
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU FEB 24 2011

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED FROM A 1010 
MB LOW PRES NEAR 05N78W TO 03N100W TO 05N107W TO 07128W TO 
05N140W. NO SIGNIFICANT CONVECTION.

...DISCUSSION...

AN ANTICYCLONE ALOFT SW OF THE GULF OF TEHUANTEPEC NEAR 10N100W 
WILL MIGRATE NE TO THE TEHUANTEPEC COAST THROUGH SAT MORNING. 
STRONG SUBSIDENCE ACCOMPANIES THE ANTICYCLONE AS EVIDENCED IN 
RECENT WATER VAPOR IMAGERY. THERE IS NO SIGNIFICANT DEEP 
CONVECTION OVER CENTRAL AMERICA AND ADJACENT WATERS AS A RESULT. 
LOW TO MID LEVEL MOISTURE HAS INCREASED OVER THE PAST 24 HOURS 
ALONG THE COLOMBIA COAST IN THE VICINITY OF A 1010 MB LOW PRES 
AT THE SURFACE NEAR 05N78W...BUT DRY AIR ALOFT IS LIMITING THE 
DEVELOPMENT OF DEEP CONVECTION. AN UPPER TROUGH LIES TO THE W OF 
THE ANTICYLONE FROM NW MEXICO TO NEAR 20N125W THEN CONTINUES S 
TO NEAR 7N125W. MID TO UPPER LEVEL MOISTURE IS BEING TRANSPORTED 
NORTHEASTWARD FROM 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. 

ELSEWHERE AT THE SURFACE...A SFC TROUGH IS EMBEDDED WITHIN THE 
ITCZ AND EXTENDS FROM 8N129W TO 5N130W. THERE IS AN AREA OF 
MULTILAYERED CLOUDINESS NEAR THE TROUGH...BUT THERE IS NO 
SIGNIFICANT DEEP CONVECTION. HIGH PRES CENTERED NEAR 32N134W 
EXTENDS A RIDGE OVER MUCH OF THE FORECAST AREA. THIS FEATURE 
WILL MOVE INTO THE NW WATERS FRI MORNING AS A NEW COLD FRONT 
APPROACHES TO THE AREA FROM THE N. 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 TONIGHT. THESE CONDITIONS WILL PERSIST 
FOR ABOUT 24 HOURS THEN WINDS WILL INCREASE TO 20 KT N OF 26N 
AND E OF 116W IN 24 HOURS AND ACROSS THE N PORTION OF THE GULF 
OF CALIFORNIA IN 48 HOURS AS A COLD FRONT ENTERS THE FAR N 
WATERS BY EARLY SAT MORNING. A NEW POSITIVELY TILTED NORTHERN 
STREAM TROUGH WILL SUPPORT THIS COLD FRONT.

THE PRES GRADIENT BETWEEN THE ANOMALOUSLY SOUTHERN ITCZ AND THE 
RIDGING N OF IT IS MAINTAINING FRESH TO STRONG TRADE WINDS AS 
FAR S AS 05N IN WESTERN WATERS ACCORDING TO THE 24/1524Z WINDSAT 
PASS AND THE 24/1908Z ASCAT PASS. THIS AREA OF TRADES IS 
EXPECTED TO REMAIN RELATIVELY UNCHANGED UNTIL MIDDAY FRI WHEN 
THE NEW NORTHERN STREAM TROUGH AND ASSOCIATED COLD FRONT BEGIN 
TO WEAKEN THE SURFACE RIDGE TO THE NORTH. 

GAP WINDS...
THE GULF OF PAPAGAYO...NORTHEASTERLY WINDS OF 20 KT WILL CONTINUE
TO FUNNEL THROUGH THE GULF OF PAPAGAYO UNTIL FRIDAY AFTERNOON.

$$
GR