000
AXPZ20 KNHC 222130
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU DEC 22 2011

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS FROM 07N81W TO 06N95W. THE ITCZ 
AXIS EXTENDS FROM 06N95W TO 08.5N115W WHERE THERE IS A BREAK IN 
THE ITCZ AS A RESULT OF A SURFACE TROUGH FROM 12N116W TO 
07N119W. THE ITCZ THEN CONTINUES FROM 08N120W TO 07N140W. 
SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 90 NM N OF AXIS 
BETWEEN 126W AND 136W. 

...DISCUSSION...

HIGH PRES 1029 MB IS CENTERED N OF THE AREA NEAR 37N135W WITH 
SURFACE RIDGE EXTENDING SE TO NEAR16N103W. THE PRESSURE GRADIENT 
BETWEEN LOWER PRESSURE IN THE VICINITY OF THE ITCZ IS SUPPORTING 
FRESH TRADEWINDS REACHING AS FAR E AS 112W. HIGH PRESSURE WILL 
FURTHER BUILD N OF THE AREA BY FRI FURTHER STRENGTHENING THE 
TRADEWINDS AND EXPANDING THE AREAL COVERAGE OF THE FRESH TO 
STRONG TRADEWINDS. 

GAP WINDS...
GULF OF CALIFORNIA...LATEST 1658 UTC ASCAT PASS INDICATES WINDS 
OVER THE GULF OF CALIFORNIA HAVE FRESHENED N OF 30N. WINDS WILL 
FURTHER INCREASE AND SPREAD SOUTHWARD OVERNIGHT IN RESPONSE TO 
HIGH PRES BUILDING IN EXCESS OF 1040 MB IN THE GREAT BASIN. 
WINDS ARE EXPECTED TO INCREASE TO GALE FORCE OVERNIGHT. THE GALE 
SHOULD BE RELATIVELY SHORT LIVED AS HIGH PRES IS EXPECTED TO 
SHIFT EASTWARD INTO THE PLAINS OVER THE WEEKEND...WEAKENING THE 
PRES GRADIENT OVER THE GULF OF CALIFORNIA. HOWEVER..NEAR GALE 
WINDS ARE EXPECTED TO CONTINUE THROUGH AT LEAST SAT AFTERNOON.

GULF OF TEHUANTEPEC...COLD FRONT CURRENTLY OVER THE GULF OF 
MEXICO IS EXPECTED TO REACH THE BAY OF CAMPECHE FRI. WINDS 
FUNNELING THOUGH THE CHIVELA PASS WILL STRENGTHEN WINDS OVER THE 
GULF OF TEHUANTEPEC BY FRI MORNING. WINDS ARE FORECAST TO REACH 
GALE FORCE OVERNIGHT FRI INTO SAT AS HIGH PRES BEGINS TO EMERGE 
IN THE SOUTHERN PLAINS...TIGHTENING THE PRES GRADIENT OVER 
TEHUANTEPEC.

GULF OF PAPAGAYO...WINDS OVER THE GULF OF PAPAGAYO HAVE 
DIMINISHED BELOW 20 KT. BUILDING HIGH PRESSURE OVER CENTRAL 
AMERICA WILL ALLOW FOR 20 KT GAP WINDS TO RESUME BY SAT MORNING. 

$$
AL