000
AXPZ20 KNHC 190909
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON DEC 19 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0645 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS FROM 09N82W TO 07N90W. ITCZ AXIS 
EXTENDS FROM 07N90W TO 05N110W TO 09N125W TO BEYOND 08N140W. 
ISOLATED MODERATE CONVECTION IS WITHIN 120 NM N OF THE AXIS FROM 
97W TO 112W. 

...DISCUSSION...

THE UPPER PATTERN FEATURES A MEAN TROUGH OVER NW MEXICO THAT 
WILL BE RELOADED WITH NORTHERN STREAM ENERGY BY THE END OF THE 
PERIOD WED MORNING AND A RIDGE EXTENDING INTO THE NW CORNER OF 
THE FORECAST AREA NEAR 31N140W FROM AN ANTICYCLONE CURRENTLY 
LOCATED NEAR 12N115W. EXPECT THE ANTICYCLONE TO DRIFT E OVER THE 
NEXT FEW DAYS. RIDGING AT THE SURFACE LIES OVER MUCH OF THE 
NORTHERN HALF OF THE FORECAST AREA STEMMING FROM 1034 MB HIGH 
PRES NEAR 41N135W. THE PRES GRADIENT BETWEEN THIS RIDGING AND 
TROUGHING ALONG THE ITCZ IS INDUCING FRESH TRADE WINDS GENERALLY 
FROM 10N TO 20N W OF 115W. THESE TRADE WINDS WILL SHRINK W ABOUT 
5 DEGREES EACH DAY AS THE MEAN TROUGHING OVER NW MEXICO RELOADS 
AND IMPINGES ON THE RIDGE OVER NE WATERS. THIS WILL ALSO CAUSE 
THE FRESH TO STRONG NW TO N WINDS ALONG THE MEXICAN COAST NEAR 
CABO CORRIENTES AND NORTH INTO THE SE PORTION OF THE GULF OF 
CALIFORNIA TO DIMINISH BY TUE MORNING.

GAP WINDS...
GULF OF TEHUANTEPEC...WHILE THE 0014 UTC WINDSAT PASS ONLY 
SHOWED WINDS TO 30 KT IN THE GULF OF TEHUANTEPEC...THE GALE 
WARNING REMAINS IN EFFECT THROUGH SUNRISE AS EARLY MORNING 
DRAINAGE FLOW IS EXPECTED TO ENHANCE THE WINDS. HIGH PRES WILL 
SHIFT E OUT OF THE WESTERN GULF OF MEXICO TODAY..REDUCING THE 
PRES GRADIENT ACROSS SOUTHERN MEXICO BETWEEN THIS HIGH AND THE 
MONSOON TROUGH TO THE S AND ENDING THE GALE EVENT.   

GULF OF PAPAGAYO...THE SAME PRES GRADIENT THAT IS FORCING GALE 
WINDS IN THE GULF OF TEHUANTEPEC IS ALSO YIELDING FRESH TO 
STRONG NE-E WINDS IN THE GULF OF PAPAGAYO. THE 0350 UTC ASCAT 
PASS CAUGHT THE WESTERN EDGE OF THE NE TO E WINDS THAT EXTEND 
W-SW FROM PAPAGAYO AND REPORTED 25 KT WINDS AS FAR AS 180 NM 
DOWNWIND OF THE GULF. THESE WINDS WILL BEGIN TO DIMINISH TODAY 
AS HIGH PRES TO THE N SHIFTS EASTWARD...BUT WILL REMAIN FRESH 
THROUGH AT LEAST WED MORNING.

$$
SCHAUER