000
AXPZ20 KNHC 250330 AAA
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN DEC 25 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS FROM 09N83W TO 07N102W. THE ITCZ 
AXIS EXTENDS FROM 07N102W TO 10N128W TO BEYOND 08N140W. ISOLATED 
MODERATE TO STRONG CONVECTION WAS NOTED WITHIN 60 NM S OF ITCZ 
AXIS FROM 102W TO 106W. SCATTERED MODERATE CONVECTION WAS NOTED 
WITHIN WITHIN 30 NM N AND 60 NM S OF ITCZ AXIS FROM 106W TO 110W.

...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 EVENING. 

GULF OF TEHUANTEPEC...RECENT ASCAT AND WINDSAT PASSES INDICATE 
GALE FORCE WINDS ARE NO LONGER OCCURRING OVER THE GULF OF 
TEHUANTEPEC. ANOTHER SURGE OF COLD AIR WILL REACH THE BAY OF 
CAMPECHE SUN...AND WINDS ARE EXPECTED TO INCREASE TO GALE FORCE 
AGAIN BY SUN NIGHT. WINDS ARE THEN EXPECTED TO DIMINISH BELOW 
GALE FORCE LATE 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 1031 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. THE AREA OF HIGH PRESSURE WILL MERGE WITH AN AREA OF HIGH 
PRESSURE TO ITS WEST THROUGH SUN. A SURFACE TROUGH CURRENTLY 
EXTENDS FROM 15N129W TO 08N131W. 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 BY SUN AFTERNOON. 

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AL