000
AXPZ20 KNHC 152130
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE NOV 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

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

THE MONSOON TROUGH IS ALONG 10N86W TO 1009 MB LOW PRES NEAR 
09N89W TO 08N108W. THE INTERTROPICAL CONVERGENCE ZONES AXIS 
EXTENDS FROM 08N108W TO 11N116W THEN RESUMES FROM 08N119W TO 
08N137W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS 
FROM 09N TO 12N BETWEEN 112W AND 120W. SIMILAR CONVECTION IS 
FROM 05N TO 08N BETWEEN 130W AND 133W.

...DISCUSSION...

AN UPPER LEVEL RIDGE IS ACROSS THE NW PORTION OF THE DISCUSSION 
AREA WITH THE MEAN AXIS FROM 32N133W TO 22N123W. MID TO HIGH 
LEVEL MOISTURE IS INTRUDING OVER THE W PORTION OF THE AREA W OF 
130W AS INDICATED BY WATER VAPOR SATELLITE IMAGERY. MAINLY ZONAL 
WESTERLY UPPER LEVEL FLOW IS E OF THE RIDGE WITH 40-50 KT JET 
LEVEL WINDS INCREASING TO 60-70 KT OVER NORTHERN MEXICO. STRONG 
SUBSIDENCE WITH DRY AND STABLE AIR AT THE MIDDLE AND UPPER 
LEVELS IS ACROSS THE AREA N OF 20N E OF 130W. AN UPPER LEVEL 
ANTICYCLONIC CIRCULATION IS SW OF MEXICO NEAR 13N99W WITH 
SIMILARLY DRY AND STABLE AIR N OF 10N E OF 110W.

IN THE DEEP TROPICS...AN UPPER LEVEL CYCLONIC CIRCULATION IS 
CENTERED NEAR 04N115W. AN UPPER LEVEL RIDGE IS W OF THE CYCLONIC 
CIRCULATION EXTENDING FROM 04N140W TO 10N121W. UPPER LEVEL 
DIFFLUENT FLOW IS ENHANCING CONVECTION ALONG THE ITCZ AS 
DESCRIBED IN THE SECTION ABOVE.

AT THE SURFACE...1032 MB HIGH PRES IS NW OF THE DISCUSSION AREA 
NEAR 37N138W WITH A RIDGE EXTENDING INTO THE AREA NEAR 32N134W 
CONTINUING TO NEAR 16N105W. RECENT SCATTEROMETER PASSES INDICATE 
WINDS LESS THAN 20 KT ACROSS THE RIDGING...ALTHOUGH AN AREA OF 
NW SWELL OF 8-10 FT EXISTS N OF 27N BETWEEN 120W AND 130W. THIS 
SWELL WILL GRADUALLY SUBSIDE TO 9 FT DURING THE NEXT 24-48 
HOURS. 

A 1009 MB AREA OF LOW PRES IS EMBEDDED IN THE MONSOON TROUGH 
NEAR 10N86W WITH A FEW SHOWERS NEAR THE LOW CENTER. A PAIR OF 
SURFACE TROUGHS ARE ANALYZED ALONG THE ITCZ. THE FIRST EXTENDS 
FROM 13N117W TO 08N118W...WITH THE SECOND EXTENDING FROM 14N138W 
TO 09N140W. ASSOCIATED CONVECTION IS AS IS DESCRIBED ABOVE. NO 
DEVELOPMENT OF THESE FEATURES IS ANTICIPATED DURING THE NEXT 48 
HOURS.

ELSEWHERE AT THE SURFACE...NW SWELL TO 9 FT COVERS THE AREA S OF 
A LINE FROM 20N140W TO 13N110W AND W OF 110W...AS CONFIRMED BY A 
18 UTC ENVISAT ALTIMETER PASS. THIS SWELL WILL GRADUALLY SUBSIDE 
AND SHRINK IN COVERAGE THROUGH THE NEXT 48 HOURS...ENCOMPASSING 
THE WATERS FROM 09N TO 14N BETWEEN 120W AND 127W BY THU 
AFTERNOON. A TIGHT PRES GRADIENT WILL DEVELOP OVER THE GULF OF 
CALIFORNIA REGION WED EVENING AND MODEL GUIDANCE INDICATES NW-N 
20 KT WINDS OVER THE NORTHERN GULF FROM 00 UTC THU THROUGH 18 
UTC THU.

GAP WINDS...THE NEXT COLD FRONT WILL MOVE THROUGH THE SW GULF OF 
MEXICO THU THROUGH FRI WITH NORTHERLY WINDS FUNNELING THROUGH 
THE CHIVELA PASS BEHIND IT. THE LATEST GFS INDICATES GALE FORCE 
WINDS BEHIND THE FRONT THU NIGHT (JUST BEYOND 48 HOURS) HOWEVER 
THE ECMWF IS MORE CONSERVATIVE WITH WINDS TOPPING OUT AT 25 KT. 
WILL CONTINUE TO MONITOR THIS POTENTIAL EVENT IN CASE A GALE 
WARNING IS NEEDED.

$$
LEWITSKY