000
AXPZ20 KNHC 152206
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU DEC 15 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 100 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH AXIS FROM 09N84W TO 06N93W TO 06N101W THEN ITCZ 
TO 08N124W.  SCATTERED MODERATE CONVECTION WITHIN 180 NM OF AXIS 
E OF 102W. ISOLATED MODERATE CONVECTION WITHIN 60 NM S OF AXIS 
FROM 123W TO 127W.

...DISCUSSION...
DEEP LAYER LONG WAVE TROUGH FROM WESTERN TEXAS ACROSS NW MEXICO 
TO 08N120W DRIES OUT CENTRAL PORTIONS OF BASIN WHILE ANTICYCLONE 
AT 08N127W WITH CREST TO 32N135W ADVECTS PLENTY OF UPPER LEVEL 
MOISTURE INTO BASIN.  ON THE EASTERN THIRD OF BASIN...MID TO 
UPPER LEVEL RIDGE EXTENDS FROM SOUTH AMERICA ACROSS CENTRAL 
AMERICA AND ALSO BRINGS PLENTY OF MOISTURE INTO MONSOON TROUGH 
AXIS E OF 102W. 

SHORT WAVE TROUGH AND ASSOCIATED MID TO UPPER CYCLONE DROPPING 
SE ACROSS CALIFORNIA INTO BACKSIDE OF MEAN TROUGH FORECAST BY 
GUIDANCE TO DEVELOP UPPER LEVEL CYCLONE OVER SRN CALIFORNIA AND 
NRN BAJA CALIFORNIA FRI AND SAT THEN MOVE E SUN.  THIS WOULD 
SUPPORT COLD FRONT BOUNDARY INTO NE PORTIONS OF BASIN WITH FRESH 
N WINDS AND SEAS TO 10 FT BEHIND FRONT TONIGHT.

HIGH PRES CENTER 1032 MB N OF 30N KEEP TIGHT GRADIENT WITH ITCZ 
TO SUPPORT FRESH NE TRADE WINDS W OF 130W.  TRADE WIND COVERAGE 
SHRINK AS COLD FRONT ERODES HIGH PRES AND EASES GRADIENT BY SAT.

N WINDS ACROSS GULF OF TEHUANTEPEC FORECAST TO INCREASE FRI 
NIGHT AND SAT TO STRONG AS NEW COLD FRONT CROSSES GULF OF MEXICO 
FORCING STRONG WINDS ACROSS CHIVELAS PASS IN THE ISTHMUS OF 
TEHUANTEPEC.  WINDS ALSO INCREASE IN GULF OF PAPAGAYO WITHIN 36 
HOURS BECOMING STRONG BY LATE SAT.

$$
WALLY BARNES