000
AXPZ20 KNHC 280332
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON FEB 28 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 
0315 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED FROM 06N77W 
TO 00N96W...REMAINS S OF THE EQUATOR BETWEEN 97W AND 107W... 
THEN CROSSES THE EQUATOR AT 108W CONTINUING NW TO 06N120W 
TURNING SW TO BEYOND 04N140W. SCATTERED MODERATE AND ISOLATED 
STRONG CONVECTION IS CONFIRMED BY LIGHTNING DATA OVER THE 
DISCUSSION AREA WITHIN 60 NM EITHER SIDE OF A LINE FROM 05N82W 
TO 04N97W. SCATTERED MODERATE TO STRONG RECENTLY DEVELOPED 
WITHIN 15 NM OF 07.5N82.5W. SCATTERED MODERATE CONVECTION HAS 
BEEN FLARING THE PAST FEW HOURS WITHIN 15 NM EITHER SIDE OF A 
LINE FROM 07N117W TO 06N122W...AND ALSO WITHIN 15 NM OF  
05.5N139W.

...DISCUSSION...

A SERIES OF UPPER SHORT WAVES ARE PASSING E THROUGH THE AREA N 
OF 25N BETWEEN 132W AND 146W. DEBRIS MOISTURE IS SPREADING NE 
ACROSS THE NW PORTION...ROUGHLY WITHIN 180 NM EITHER SIDE OF 
LINE 30N132W TO 25N143W. 

A DEEP LAYERED CYCLONE IS LIFTING NE ACROSS NEW MEXICO TRAILING 
A MID TO UPPER TROUGH SW FROM 32N110W TO A BASE NEAR 26N124W. 
DRY UPPER AIR IS OBSERVED N OF 28N E OF 124W BUT WILL SOON SHIFT 
N OF THE AREA BEING REPLACED BY MOIST UPPER AIR DESCRIBED LATER.
THE ASSOCIATED SURFACE COLD FRONT IS WASHING OUT OVER THE 
SOUTHERN GULF OF CALIFORNIA AND ALONG 21N BETWEEN 115W AND 130W. 
THE POST FRONTAL GRADIENT WILL SUPPORT NW TO N SURFACE WINDS AT 
15 TO 20 KT OVER THE GULF OF CALIFORNIA THROUGH EARLY MON 
NIGHT. NORTHERLY WINDS AT 15 TO KT ALSO ACCOMPANY THE FRONT 
ALONG THE W COAST OF THE BAJA CALIFORNIA PENINSULA 
TONIGHT...WITH SEAS 9 TO 13 FT IN LONG PERIOD NW SWELL OVER THE 
PACIFIC WATERS N OF 25N E OF 122W. THESE SEAS ARE FORECAST TO 
SUBSIDE TO LESS THAN 8 FT IN 48 HOURS OVER THE E PORTION...BUT 
WILL INCREASE AGAIN OVER THE NW PORTION AS A SECOND FRONT 
ARRIVES TUE PRECEDED BY SOUTHERLY WINDS OF 20 TO 30 KT AND 
ANOTHER BOUT OF NW LONG PERIOD SWELLS. 

AN UPPER RIDGE EXTENDS NE FROM THE SOUTHERN HEMISPHERE OVER THE 
DEEP TROPICS ALONG 00N140W TO A CREST AT 06N133W AND IS 
ACCOMPANIED BY DRY UPPER AIR. AN UPPER TROUGH IS NOTED OVER THE 
DEEP TROPICS FROM 00N123W TO 07N117W. SMALL CLUSTERS OF MODERATE 
CONVECTION HAVE FLARED AGAIN ALONG THIS TROUGH WITH THE DEBRIS 
MOISTURE QUICKLY EVAPORATING. AN UPPER LEVEL ANTICYCLONE IS 
CENTERED OVER THE BAY OF CAMPECHE WITH AN UPPER RIDGE EXTENDING 
SW TO A SHARP CREST AT 10N123W. A WELL DEFINED TROPICAL MOISTURE 
PLUME IS ADVECTED NE WITHIN A SOUTHWESTERLY JET ALONG THE NW 
PERIPHERY OF THE UPPER RIDGE...ALL WITHIN 360 NM EITHER SIDE OF 
LINE FROM 12N146W TO 23N123W. THE PLUME THEN NARROWS AND 
EVENTUALLY EVAPORATES AS IT CROSSES OVER THE THE BAJA CALIFORNIA 
PENINSULA BETWEEN 25N AND 28N. DENSE DEBRIS MOISTURE ORIGINATING 
FROM CONVECTION OVER COLOMBIA AND THE ITCZ CONVECTION PREVIOUSLY 
DESCRIBED...IS SPREADING W OVER THE AREA S OF 10N E OF 93W. 
OTHERWISE THE UPPER LEVELS ARE VERY DRY S OF 22N E OF 120W.     
 
ELSEWHERE AT THE SURFACE...A RIDGE IS BRIDGING THE DECAYING COLD 
FRONT ALONG 21N BETWEEN 115W AND 130W. THE PRESSURE GRADIENT SW 
OF THE RIDGE AND N OF THE ITCZ IS MAINTAINING A SMALL AREA OF 15 
TO 20 KT NE WINDS...ROUGHLY FROM 07N TO 11N W OF 120W. THESE 
TRADES WILL SPREAD N TO THE AREA FROM 07N TO 17N BETWEEN 115W 
AND 130W ON MON. 

GULF OF PAPAGAYO...NE TO E WINDS WILL CONTINUE TO PULSE AT 15 TO 
20 KT THROUGH TUE MORNING...WITH ENHANCED DRAINAGE FLOW OFF 
THE CENTRAL AMERICA LANDMASS LATE AT NIGHT THROUGH EARLY 
MORNING.

GULF OF TEHUANTEPEC...A COLD FRONT WILL SWEEP SE ACROSS THE GULF 
OF MEXICO ON MON. NORTHERLY WINDS WILL INCREASE TO 15 TO 20 KT 
IN THE GULF OF TEHUANTEPEC EARLY MON NIGHT...FURTHER INCREASING 
TO MINIMAL GALE FORCE JUST AFTER SUNRISE TUE MORNING... 
CONTINUING TO JUST AFTER SUNRISE WED MORNING....THEN QUICKLY 
DIMINISH WED AFTERNOON.       

$$
NELSON