000
AXPZ20 KNHC 161521
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON JAN 16 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 
1300 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS FROM 07N77W TO 06N80W TO 08N80W 
TO 05N92W. THE ITCZ AXIS EXTENDS FROM 05N92W TO 06N106W TO 
05N115W TO 07N128W TO 06N140W. SCATTERED MODERATE WITH ISOLATED 
STRONG CONVECTION LIES WITHIN 120 NM S AND 60 NM N OF THE AXIS E 
OF 80W. SCATTERED MODERATE CONVECTION LIES WITHIN 150 NM N OF 
THE AXIS W OF 130W.

...DISCUSSION...

THE MEAN TROUGH AXIS ALOFT CUTS ACROSS THE FORECAST AREA FROM 
30N120W TO 15N140W THIS MORNING. A SOUTHWESTERLY JET WITH 
TROPICAL ORIGINS LIES AHEAD OF THE TROUGH AXIS AND IS 
TRANSPORTING MOISTURE...PRIMARILY MANIFESTED AS CIRRUS...FROM 
JUST N OF THE ITCZ AT 140W INTO THE SOUTHERN GULF OF CALIFORNIA. 
THE NORTHERN PORTION OF THE TROUGH IS FORECAST TO ADVANCE 
EASTWARD...LEAVING BEHIND SOME ENERGY OVER NORTHERN WATERS THAT 
IS EXPECTED TO DEVELOP INTO A CUT OFF LOW BY WED AS DEEP LAYER 
RIDGING BECOMES ESTABLISHED TO ITS N. 

AT THE SURFACE...HIGH PRES WILL GRADUALLY BUILD N OF THE AREA AS 
THE MEAN TROUGH MOVES OUT AND IS REPLACED BY RIDGING. NW TO N 
WINDS BEHIND THE DISSIPATED COLD FRONT OVER THE PACIFIC 
ASSOCIATED WITH THE MEAN TROUGH GENERATED A NW SWELL TRAIN THAT 
IS BEGINNING TO MOVE INTO THE FORECAST AREA AND EXPECTED TO 
BRING SIGNIFICANT WAVE HEIGHTS AS HIGH AS 10 FT TO WATERS N OF 
20N THROUGH WED. MEANWHILE...THE EXPANSION OF THE SUBTROPICAL 
HIGH BEHIND THIS DISSIPATED FRONT WILL ALLOW FRESH TRADES TO 
BUILD OVER THE AREA. A WEAK TROUGH IS EXPECTED TO BE REFLECTED 
AT THE SURFACE BY WED FROM THE AFOREMENTIONED CUT OFF LOW ALOFT 
AND WINDS WILL BECOME STRONG BETWEEN THIS TROUGH AND THE 
SUBTROPICAL HIGH AS THE PRESSURE GRADIENT TIGHTENS. THE PRES 
GRADIENT WILL ALSO TIGHTEN OVER THE SOUTHERN GULF OF CALIFORNIA 
AND OFF THE COAST OF CABO CORRIENTES...MEXICO BETWEEN THE 
BUILDING SUBTROPICAL HIGH AND LOWERING SURFACE PRESSURES TO THE 
E ATTRIBUTABLE TO A COLD FRONT ASSOCIATED WITH THAT EASTWARD 
MOVING MEAN TROUGH. FRESH NW TO N WINDS ARE EXPECTED HERE 
OVERNIGHT TUE NIGHT.

GAP WINDS...

GULF OF TEHUANTEPEC...THE WINDSAT PASS FROM 0020 UTC AND THE 
ASCAT PASS FROM 0412 UTC FAILED TO SHOW WINDS IN THE GULF OF 
TEHUANTEPEC ABOVE 30 KT. IN ADDITION...THE DRIVING HIGH PRES 
THAT HAD BEEN IN THE N CENTRAL GULF OF MEXICO YESTERDAY HAS 
DRIFTED WELL NE INTO THE U.S. MID ATLANTIC STATES. THE GALE 
WARNING IN THE GULF OF TEHUANTEPEC WAS DROPPED AT 0600 UTC BASED 
ON THIS INFORMATION. WINDS ARE EXPECTED TO DIMINISH BELOW 20 KT 
BY TUE AFTERNOON.

GULF OF PAPAGAYO...THE HIGH PRES SYSTEM THAT DROVE THE GALE 
IN THE GULF OF TEHUANTEPEC HAS SHIFTED EASTWARD AND NOW LIES N 
OF THE GULF OF PAPAGAYO. WHILE THE HIGH CENTER IS EXPECTED TO 
DRIFT SE OVER THE NEXT FEW DAYS...THE PRES GRADIENT OVER THE 
GULF OF PAPAGAYO SHOULD REMAIN RELATIVELY UNCHANGED. FRESH TO 
STRONG NE TO E WINDS ARE EXPECTED TO CONTINUE DOWNWIND OF 
PAPAGAYO TO ABOUT 91W THROUGH WED MORNING WITH THE AREA OF SEAS 
OVER 8 FT IN THE RESULTING NE SWELL EXPECTED TO EXPAND 
DOWNSTREAM AS FAR AS 110W THROUGH WED MORNING.

$$
SCHAUER