000
AXPZ20 KNHC 092157
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED MAR 09 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 03N78W 
TO 03N95W TO 04N106W TO 04N125W TO 06N140W. SCATTERED MODERATE 
WITHIN 100 NM S OF AXIS BETWEEN 94W AND 97W.

...DISCUSSION...

ALOFT...A TROUGH/RIDGE/TROUGH PATTERN DOMINATES THE FORECAST 
REGION. AN UPPER LEVEL ANTICYCLONE NEAR 06N105W EXTENDS A RIDGE 
TO THE N BEYOND BAJA CALIFORNIA. SW FLOW IS NOTED OVER THE NW 
CORNER AHEAD OF A DEEP LAYER TROUGH THAT SUPPORTS A COLD FRONT 
CURRENTLY APPROACHING THE FAR NW PART OF THE AREA. MULTI-LAYERED 
CLOUDINESS CAN BE FOUND OVER MUCH OF THE AREA N OF THE ITCZ AND 
W OF 130W WHERE THE SW-W FLOW ALOFT IS TRANSPORTING TROPICAL 
MOISTURE FROM S OF HAWAII INTO THE FORECAST AREA.

AT THE SURFACE...1027 MB HIGH PRES NEAR 31N128W EXTENDS A RIDGE 
ACROSS THE FORECAST WATERS COVERING MAINLY THE AREA N OF 18N W 
OF 110W. TRADE WINDS OF 20 KT ARE NOTED ON THE SOUTHERN 
PERIPHERY OF THE RIDGE PARTICULARLY N OF THE ITCZ TO AROUND 15N 
AND W OF 125W WHERE BOTH THE 1458 UTC WINDSAT PASS...AND THE 
1802 ASCAT PASS SHOW NE WINDS OF 20 KT. HIGH PRES OVER THE GREAT 
BASIN IS RESULTING IN NW WINDS OF 20 KT ACROSS THE GULF OF 
CALIFORNIA N OF 28N. SURFACE DATA FROM SAN FELIPE IN NORTHERN 
BAJA CALIFORNIA PENINSULA VERIFIED THESE WIND SPEEDS. WINDS WILL 
BE BELOW 20 KT IN THIS AREA IN ABOUT 24 HOURS. 

A COLD FRONT IS APPROACHING THE FAR NW CORNER OF THE AREA AND 
WILL EXTEND FROM 30N138W TO 28N140W TONIGHT THEN STALL FROM 
30N136W TO 28N140W BY THU AFTERNOON AND BEGIN TO DISSIPATE OVER 
FORECAST WATERS THU EVENING. NW SWELL WILL FOLLOW THE FRONT   
AND STEADILY INCREASE TO 14 FT LATE THU...THEN SPREAD ACROSS THE 
FORECAST AREA NW OF LINE FROM 30N120W TO 21N130W TO 16N140W 
WHILE SLIGHTLY SUBSIDING TO 12 FT.

GAP WINDS...
GULF OF TEHUANTEPEC...A STRONG COLD FRONT WILL PASS THROUGH THE 
WESTERN GULF OF MEXICO TONIGHT AND BEGIN TO PUSH THROUGH THE 
ISTHMUS OF TEHUANTEPEC BY THU MORNING. WINDS WILL QUICKLY 
INCREASE TO GALE FORCE THU MORNING AND REACH 40 KT BY EARLY FRI 
WITH SEAS AS HIGH AS 18 FT.

GULF OF PAPAGAYO...EXPECT NE WINDS OF 20 KT THROUGH THIS GULF BY 
FRI MORNING AS PRES GRADIENT STRENGTHENS ACROSS THE WESTERN 
CARIBBEAN.

$$
GR