000
AXPZ20 KNHC 010337
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE MAR 01 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 
0330 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED FROM 07N77W 
TO 02N98W...THEN RESUMES FROM 05N107W TO 04N112W TO 06N120W TO 
05N135W TO 06N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION IS NOTED WITHIN 60 NM OF 05N81W AND ALSO WITHIN 30 NM 
EITHER SIDE OF A LINE FROM 08N81W TO 07N86W...AND ALSO WITHIN 90 
NM EITHER SIDE OF A LINE FROM 08N122W TO 05N130W.
 
...DISCUSSION...

AN UPPER LEVEL TROUGH IS PASSING E THROUGH THE AREA N OF 25N 
BETWEEN 130W AND 140W WITH DENSE DEBRIS MOISTURE SPREADING NE 
ACROSS THIS AREA AS WELL. AN UPPER LEVEL ANTICYCLONE IS CENTERED 
OVER THE BAY OF CAMPECHE AT 20N95W WITH AN UPPER RIDGE 
EXTENDING SW TO A SHARP CREST AT 08N120W. A TROPICAL MOISTURE 
PLUME IS ADVECTED NE ALONG THE NW PERIPHERY OF THIS UPPER 
RIDGE...ROUGHLY WITHIN 360 NM EITHER SIDE OF LINE FROM 10N137W 
TO 21N121W...THEN NARROWS TO WITHIN 120 NM OF POINTS 24N117W TO 
30N108W. DEBRIS MOISTURE...ORIGINATING FROM ITCZ CONVECTION 
BETWEEN 122W AND 132W...IS NOTED WITHIN 120 NM EITHER SIDE OF A 
LINE FROM 04N133W TO 05N125W TO 12N118W WHERE IT EVAPORATES. 
DENSE DEBRIS MOISTURE ORIGINATING FROM CONVECTION OVER COLOMBIA 
AND THE ITCZ CONVECTION E OF 82W PREVIOUSLY DESCRIBED...IS 
SPREADING W OVER THE AREA S OF 10N E OF 96W. OTHERWISE THE UPPER 
LEVELS ARE VERY DRY S OF 24N E OF 114W.  

AT THE SURFACE...A COLD FRONT IS APPROACHING THE NW PORTION WITH 
SOUTHERLY FLOW ALREADY AT 15 TO 20 KT OVER THE AREA N OF 24N W 
OF 135W. EXPECT THIS FRONT TO REACH ALONG 30N134W TO 25N140W ON 
TUE WITH THE SOUTHERLY FLOW INCREASING TO 20 TO 30 KT JUST AHEAD 
OF THE FRONT LATE TONIGHT. THE LOW LEVEL FLOW E OF THE FRONT 
WILL DIMINISH LATE WED AS THE FRONT SLOWS ITS EASTWARD 
PROGRESS...BUT A NEW TRAIN OF LONG PERIOD NW SWELLS WILL MOVE 
INTO THE NW PORTION W OF THE FRONT DRIVING SEAS UP TO 11 FT.
THIS NEXT ROUND OF NW SWELLS WILL SUBSIDE OVER THE NW WATERS THU 
AND FRI. 

FURTHER E...HIGH PRESSURE DOMINATES THE SUBTROPICS WITH THE 
GRADIENT SW OF THE RIDGE AND TO THE N OF THE ITCZ MAINTAINING A 
SMALL AREA OF 15 TO 20 KT NE WINDS...ROUGHLY FROM 07N TO 13N 
BETWEEN 115W AND 132W. THESE TRADES WILL CONTINUE THROUGH THU AS 
THE LONG PERIOD N SWELLS DIMINISH OVER THE DISCUSSION AREA W OF 
110W.  

GULF OF CALIFORNIA...NW WINDS AT 15 TO 20 KT ARE OBSERVED OVER 
THE GULF S OF 30N...BUT EXPECTED TO SHRINK TO THE WATERS S OF 
27N ON TUE AND S OF 26N ON WED.

GULF OF PAPAGAYO...NE TO E WINDS WILL CONTINUE TO PULSE AT 15 TO 
20 KT THROUGH TUE MORNING THEN INCREASE TO 20 TO 25 KT ON WED 
MORNING.

GULF OF TEHUANTEPEC...A COLD FRONT IS SWEEPING SE ACROSS THE 
CENTRAL GULF OF MEXICO AND POST FRONTAL NORTHERLY WINDS AT 15 TO 
20 KT WILL SURGE INTO THE GULF OF TEHUANTEPEC EARLY TONIGHT... 
INCREASING TO MINIMAL GALE FORCE JUST AFTER SUNRISE TUE 
MORNING...WITH GALE CONDITIONS CONTINUING TO JUST AFTER SUNRISE 
WED MORNING...THEN QUICKLY DIMINISHING INTO EARLY WED EVENING. 

$$
NELSON