000
AXPZ20 KNHC 242111
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT DEC 24 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 08N82W TO 07N100W. THE ITCZ 
AXIS EXTENDS FROM 07N100W TO 08N107W TO 09.5N128W TO BEYOND 
08N140W. ISOLATED MODERATE TO STRONG CONVECTION WAS NOTED WITHIN 
60 NM S OF ITCZ AXIS FROM 104W TO 108W.  SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WAS NOTED WITHIN 120 NM N OF ITCZ 
AXIS FROM 120W TO 130W.

...DISCUSSION...
GULF OF CALIFORNIA...UPPER LEVEL TROUGH HAS HELPED INDUCE A 
SURFACE TROUGH OVER ARIZONA. THIS HAS HELPED WEAKEN THE PRESSURE 
GRADIENT AND RESULTING WINDS FLOWING INTO THE GULF OF 
CALIFORNIA. WINDS ARE CURRENTLY BELOW GALE FORCE...AND WILL 
CONTINUE TO FURTHER DIMINISH WITH ONLY A SMALL AREA OF FRESH 20 
KT WINDS REMAINING BY MONDAY. 

GULF OF TEHUANTEPEC...GALE FORCE WINDS ARE OVER THE FAR N PART 
OF THE GULF OF TEHUANTEPEC. ANOTHER SURGE OF COLD AIR WILL REACH 
THE BAY OF CAMPECHE SUN...INCREASING THE AREAL COVERAGE OF GALE 
FORCE WINDS BY SUN NIGHT. THE GALE FORCE WINDS ARE EXPECTED TO 
REMAIN THROUGH MON AFTERNOON. 

GULF OF PAPAGAYO...FRESH TRADEWINDS OVER THE WESTERN CARIBBEAN 
WILL FUNNEL INTO THE GULF OF PAPAGAYO. WINDS WILL PEAK DURING 
THE EARLY MORNING HOURS WITH THE ADDITION OF NOCTURNALLY DRIVEN 
KATABATIC WINDS.

HIGH PRES 1032 MB IS CENTERED N OF THE AREA NEAR 35N128W WITH 
SURFACE RIDGE EXTENDING SE TO NEAR 16N104W. THE PRESSURE 
GRADIENT BETWEEN THIS AREA OF HIGH PRESSURE AND LOWER PRESSURE 
IN THE VICINITY OF THE ITCZ IS IS MAINTAINING A LARGE AREA OF 
FRESH TO STRONG TRADEWINDS OVER MUCH OF THE AREA N OF 10N W OF 
110W AS DEPICTED BY LATEST 1800 UTC ASCAT PASS. THE AREA OF HIGH 
PRESSURE WILL DISSIPATE THROUGH SUN...WITH A SECOND AREA OF HIGH 
PRESSURE BUILDING RIGHT BACK IN. THIS WILL SHRINK THE AREAL 
COVERAGE OF FRESH TO STRONG TRADES TO MAINLY WEST OF 120W BY MON 
AFTERNOON. A SURFACE TROUGH CURRENTLY EXTENDS FROM 15N128W TO 
08N130W. THIS TROUGH WILL INTERACT WITH AN UPPER LEVEL TROUGH TO 
ITS WEST AND HELP STRENGTHEN THE LOW LEVEL TROUGH AS IT 
CONTINUES TO SHIFT WESTWARD. A LOCALLY TIGHTER PRESSURE GRADIENT 
BETWEEN THE TROUGH AND AFOREMENTIONED RIDGE OF HIGH PRESSURE 
WILL INCREASE WINDS LOCALLY TO NEAR GALE FORCE SUN AFTERNOON. 

$$
AL