000
AXPZ20 KNHC 121605
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU APR 12 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.

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

ITCZ EXTENDS FROM 4N109W TO 02N119W TO 01N130W. NO SIGNIFICANT CONVECTION
IS NOTED.

...DISCUSSION...

BROAD UPPER LEVEL TROUGHING COVERS THE AREA N OF 27N E OF 136W. 
A SHORTWAVE TROUGH DROPPING SEWD THROUGH THE BASE OF THE TROUGH 
EXTENDS FROM 32N129W TO 27N135W. NRN STREAM ENERGY FROM WELL W 
OF THE REGION IN FORM OF SCATTERED TO BROKEN HIGH CLOUDS IS 
RIDING SEWD INTO THE DISCUSSION AREA BETWEEN THE TROUGH AND AN 
ANTICYCLONE W OF THE AREA NEAR 28N153W. THE UPPER FLOW PATTERN 
IS GENERALLY CONFLUENT BETWEEN THE BROAD TROUGH AND AN ANTICYLONE
OVER THE FAR SRN PORTION AT 9N113W. SCATTERED TO BROKEN HIGH CLOUDS
MOVING INTO THE AREA ARE ALSO EVIDENT S OF 20N W OF 119W. VERY
STABLE ATMOSPHERIC CONDITIONS CONTINUE THROUGHOUT W OF ABOUT 100W
AS NOTED BY MODERATE SUBSIDENCE ALOFT BETWEEN THE TWO AREAS OF SCATTERED
TO BROKEN HIGH CLOUDS. BROKEN TO OVERCAST STRATOCUMULUS CLOUDS ARE
MOVING SW TO W FROM 09N TO 20N W OF 118W. AT THE SURFACE...A 
1023 MB HIGH IS AT 25N124W WITH A RIDGE SE TO NEAR 13N112W. A TIGHT
PRES GRADIENT BETWEEN THE RIDGE AND LOW PRES IN THE TROPICS IS ALLOWING
FOR NE TRADES OF 20 KT TO EXIST FROM 04N TO 19N W OF 120W. A 
COLD FRONT JUST N OF THE AREA EXTENDS SW TO 32N130W AND TO 
30N135W. 

IN THE FAR ERN PORTION OF THE AREA...A MID TO UPPER LEVEL TROUGH 
EXTENDS FROM SE MEXICO TO THE GULF OF TEHUANTEPEC AND SW TO NEAR 
05N100W. AN UPPER LEVEL RIDGE IS E OF THE TROUGH OVER MEXICO TO
OVER THE THE NRN PORTION OF S AMERICA. A SURFACE TROUGH LIES
ALONG 04N89W TO 01N98W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION
IS WITHIN 120 NM N AND 90 NM S OF THE TROUGH.

THE BROAD TROUGH MENTIONED ABOVE WILL SHIFT E OF THE AREA DURING
THEN NEXT 48 HRS...DRIVING THE COLD FRONT TO A PSN FROM 30N124W
TO 27N131W IN 24 HRS BEFORE MOVING INLAND THE SW U.S. NW TO N WINDS
OF 20 KT WILL FOLLOW IN BEHIND THE FRONT...WITH SW WINDS OF 20 KT
N OF 28N WITHIN 180 NM E OF THE FRONT. LARGE SWELLS WILL PROPAGATE
INTO THE AREA BEHIND THE FRONT THROUGH SAT.

THE COMBINATION OF THE PACIFIC RIDGE AND LOWER PRES OVER MEXICO 
HAS INCREASED NW WINDS TO 20 KT ALONG THE COAST OF BAJA 
CALIFORNIA.

$$
AGUIRRE