000
AXPZ20 KNHC 141555
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON MAR 14 2011

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED FROM 03N77W 
TO 01N83W TO 04N100W TO 04N140W. ISOLATED MODERATE CONVECTION IS 
NOTED ALONG 03N BETWEEN 86W AND 98W. SCATTERED MODERATE 
CONVECTION IS NOTED WITHIN 90 NM OF 03N95W...AND ALSO FROM 02N 
TO 08N BETWEEN 112W AND 140W.

...DISCUSSION...
A COUPLE OF UPPER TROUGHS ARE PASSING E ACROSS THE NORTHERN 
PORTION. THE WESTERNMOST TROUGH EXTENDS FROM 32N122W TO 20N136W. 
AN UPPER TROUGH DOMINATING THE CENTRAL CONUS EXTENDS INTO THE 
DISCUSSION AREA ALONG 32N102W TO 16N113W. AN UPPER ANTICYCLONE 
IS CENTERED AT 14N120W WITH AN UPPER RIDGE EXTENDING NNE AND 
CRESTING BETWEEN THE TWO AFOREMENTIONED TROUGHS AT 28N116W.  
UPPER MOISTURE IS SPREADING E OVER THE AREA N OF 28N W OF THE 
BAJA CALIFORNIA PENINSULA WITH THE MOST DENSE MOISTURE NOW 
PASSING E ACROSS SOUTHERN CALIFORNIA. DEBRIS MOISTURE FROM THE 
ITCZ CONVECTION BETWEEN 112W AND 135W SPREADS N ALONG 134W 
MERGING WITH A BAND OF UPPER MOISTURE STREAMING E FROM THE 
CENTRAL TROPICAL PACIFIC...AND CONTINUING ALONG THE NW PERIPHERY 
OF THE RIDGE...ROUGHLY WITHIN 180 NM EITHER SIDE OF LINE 10N138W 
TO 17N130W TO 20N120W. THE MOISTURE PLUME THEN NARROWS AS IT 
CONTINUES E AND NE ACROSS CENTRAL OLD MEXICO EVENTUALLY MERGING 
WITH ABUNDANT MOISTURE AHEAD OF THE CONUS TROUGH. THE RIDGE IS 
EXPECTED TO COLLAPSE SE ALLOWING THE WESTERNMOST TROUGH TO 
CONTINUE E WITH A NEW UPPER RIDGE BUILDING E ALONG 20N W OF 120W 
BY WED. THE UPPER LEVELS ARE VERY DRY S OF 18N E OF 110W AND 
SUPPRESSING CONVECTION TO THE ISOLATED CELLS PREVIOUSLY 
DESCRIBED.

AT THE LOW LEVELS HIGH PRESSURE IS CENTERED AT 30N128W RIDGING 
SE TO NEAR 15N105W AND SW TO NEAR 26N140W. THE HIGH IS FORECAST 
TO DRIFT S OVER THE NEXT COUPLE OF DAYS. NORTHERLY WINDS ARE AT 
20 TO 25 KT N OF 25N E OF 122W TO THE WESTERN COAST OF THE BAJA 
CALIFORNIA PENINSULA. ALTHOUGH SOUTHWESTERLY WINDS ARE LESS THAN 
20 KT N OF THE WESTERN RIDGE...LONG PERIOD NW SWELLS...RESULTING 
IN SEAS 10 TO 15 FT...ARE OBSERVED NW OF LINE FROM 30N128W TO 
23N140W. NW SWELLS...SEAS TO 9 FT...ARE NOTED ELSEWHERE 
THROUGHOUT THE WATERS N OF 20N W OF 108W. NORTHEAST TRADES ARE 
ENHANCED AT 15 TO 20 KT SW OF THE RIDGE...GENERALLY FROM 06N TO 
20N W OF 115W WITH SEAS 8 TO 10 FT IN MIXED NE AND NW SWELL. 
ELSEWHERE FROM 03N TO 20N W OF 107W SEAS ARE 6 TO 8 FT IN MIXED 
NE AND NW SWELL. THE GRADIENT WILL RELAX SOME THE NEXT COUPLE OF 
DAYS ESPECIALLY ALONG THE W COAST OF THE BAJA CALIFORNIA 
PENINSULA. HOWEVER...A NEW TRAIN OF LONG PERIOD NW SWELLS... 
DRIVING SEAS UP TO 18 FT...WILL PUSH INTO THE NW PORTION TUE 
NIGHT AND WED. 
 
GAP WINDS...
GULF OF TEHUANTEPEC...N WINDS WILL FUNNEL THROUGH THE ISTHMUS OF 
TEHUANTEPEC BEGINNING EARLY TUE MORNING AS HIGH PRES BUILDS OVER 
NE MEXICO. WINDS WILL PULSE TO 25 KT IN THE MORNING HOURS WHEN 
DRAINAGE FLOW THROUGH THE PASS WILL BE AT ITS DIURNAL MAXIMUM. 
SEAS WILL GRADUALLY BUILD TO ABOUT 10 FT OVER THE WATERS N OF 
11N BETWEEN 95W AND 98W BY WED. 

GULF OF PAPAGAYO...DRAINAGE FLOW OFF THE LANDMASS WILL MAINTAIN 
WINDS AT 20 KT DURING THE EARLY MORNING HOURS FOR THE NEXT FEW 
DAYS.

GULF OF PANAMA...NORTHERLY WINDS EXPECTED TO DIMINISH BELOW 20 
KT BY THIS AFTERNOON.

$$
NELSON