000
AXPZ20 KNHC 111557
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT FEB 11 2012

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

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

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

AN UNUSUALLY STRONG MONSOON TROUGH EXTENDS SW FROM THE COLOMBIAN 
AND PANAMA BORDER TO 02N86W...THEN TURNS NW THE TO BASE OF A LOW 
LEVEL TROUGH AT 10N108W...THEN TURNS SW TO 02N128W WHERE LOW 
LEVEL WINDS INDICATE A TRANSITION TO AN ITCZ WHICH CONTINUES W 
TO BEYOND 00N140W. ISOLATED MODERATE AND STRONG CONVECTION IS 
NOTED FROM 07N TO THE EQUATOR ALL TO THE E OF 100W. 

THE LOW LEVEL TROUGH EXTENDS FROM 10N108W TO THE COAST OF OLD 
MEXICO AT 17N105W. SCATTERED MODERATE ISOLATED STRONG CONVECTION 
IS OBSERVED WITHIN 120 NM EITHER SIDE OF A LINE FROM 10N106W TO 
17N101W. BROKEN TO OVERCAST LOW AND MID LEVEL CLOUDS ARE 
OBSERVED ELSEWHERE FROM 10N TO 20N BETWEEN 102W AND 108W...AND 
ARE LIKELY ACCOMPANIED BY EMBEDDED SHOWERS.   

...DISCUSSION...

AN UPPER LEVEL SHORTWAVE TROUGH IS SWINGING E ACROSS THE 
NORTHERN PORTION OF THE DISCUSSION AREA WITH ITS MEAN AXIS 
EXTENDING FROM 32N121W TO A BASE AT 22N129W. ALTHOUGH VERY DRY 
UPPER AIR IS NOTED WITHIN 120 NM W OF THE TROUGH AXIS...SOME 
UPPER MOISTURE PRECEDES THE TROUGH...AND IS CURRENTLY SPILLING E 
OVER ARIZONA. FURTHER TO THE W OF THE TROUGH AXIS IS ADDITIONAL 
MOISTURE AND IS JUST NOW MOVING ACROSS CALIFORNIA TO THE N OF 
34N. 

THE UPPER LEVELS OF THE TROPICAL EPAC IS COMPLICATED WITH AN 
UPPER ANTICYCLONE AT 07N138W RIDGING NW TO BEYOND 32N147W. 
ANOTHER UPPER ANTICYCLONE IS OVER NW COLOMBIA WITH A RIDGE 
EXTENDING NW ACROSS CENTRAL AMERICA AND OLD MEXICO TO A CREST 
OVER NEW MEXICO AT 33N106W. BETWEEN THESE TWO LARGE UPPER RIDGES 
ARE A SERIES OF UPPER CYCLONES. THE MOST NOTICEABLE AND 
EASTERNMOST CYCLONE IS AT 21N110W...AND IS MOVING N WHILE 
QUICKLY FILLING. AN UPPER TROUGH EXTENDS SW FROM THIS CYCLONE 
THROUGH ANOTHER SMALL CYCLONE AT 11N119W...THEN THE TROUGH TURNS 
NW TO YET ANOTHER SMALL AND ILL-DEFINED UPPER CYCLONE THAT IS 
EMBEDDED IN PREDOMINATE UPPER ANTICYCLONIC FLOW AT 16N125W. SOME 
UPPER MOISTURE IS SPILLING E ACROSS THE WESTERN UPPER RIDGE INTO 
THE DISCUSSION AREA FROM 11N TO 22N W OF 135W. OTHERWISE THESE 
UPPER FEATURES COMBINE TO DRY OUT THE UPPER LEVELS OF THE 
SUBTROPICS AND TROPICS BETWEEN 112W AND 135W.
        
UPPER DIFFLUENCE ALONG THE SOUTHERN PERIPHERY OF THE EASTERNMOST 
UPPER RIDGE IS ENHANCING THE ISOLATED CONVECTION ALONG THE 
MONSOON TROUGH E OF 100W AS PREVIOUSLY DESCRIBED. UPPER 
DIFFLUENCE E OF THE UPPER CYCLONE AND UPPER TROUGH ALONG 110W IS 
SUPPORTING THE CONVECTION ASSOCIATED WITH THE LOW LEVEL TROUGH 
AS PREVIOUSLY MENTIONED. THE RESULTANT DEBRIS MOISTURE SPREADS N 
ACROSS OLD MEXICO BETWEEN 100W AND 107W TO ALONG 28N...THEN THE 
MOISTURE TURNS ABRUPTLY E INTO A PLUME CONTINUING E ACROSS THE 
GULF OF MEXICO TO THE S OF 27N...ACROSS FLORIDA S OF 26N...AND 
FUELING INTO CONVECTION ASSOCIATED WITH A SHORTWAVE TROUGH OVER 
EASTERN N AMERICA WITH ITS BASE NOW PROGRESSING E THROUGH THE 
BAHAMAS.

ELSEWHERE AT THE LOW LEVELS...A RIDGE EXTENDS FROM 29N140W TO 
17N117W. NORTHERLY WINDS AT 15 TO 20 KT WILL CONTINUE NE OF THE 
RIDGE TO THE NORTHERN BAJA CALIFORNIA PENINSULA THROUGH EARLY 
SUN THEN DIMINISH BELOW 20 KT. NE TRADES TO THE S OF THE RIDGE 
CONTINUE AT 20 KT IN THE AREA FROM 09N TO 24N W OF 125W...BUT 
THIS AREA OF ENHANCED TRADES SHOULD SHRINK OVER THE 48 HOURS. 
LONG PERIOD NW SWELLS ARE MIXING WITH THE NE TRADE SWELL OVER 
THE ENTIRE DISCUSSION AREA W OF 100W...AND WILL SPREAD E TO 
ALONG 93W EARLY NEXT WEEK. THE COMBINED SEAS THAT ARE MAXING AT 
14 FT TODAY WILL SUBSIDE TO A MAX OF 11 FT SUN NIGHT.   

...GAP WINDS...
NORTHERLY WINDS AT 20 TO 25 KT SURGED ACROSS THE GULF OF 
TEHUANTEPEC AT SUNRISE THIS MORNING..AND ARE EXPECTED TO 
INCREASE TO A MINIMAL 35 KT GALE EARLY THIS AFTERNOON...FURTHER 
INCREASING TO 40 KT ON SUN MORNING....THEN DIMINISH BELOW GALE 
FORCE LATE SUN NIGHT.

FRESH TRADE WINDS IN THE SW CARIBBEAN WILL CONTINUE TO FUNNEL 
THROUGH THE PASSES OF CENTRAL AMERICA INTO AND DOWNWIND OF THE 
GULF OF PAPAGAYO THROUGH SUN NIGHT.

$$
NELSON