000
AXPZ20 KNHC 071603
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON NOV 7 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 07N78W TO 08N105W TO 12N114W TO 
10N118W...THEN TRANSITIONS TO ITCZ AXIS FROM 10N118W TO 07N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 60 NM OF 
AXIS W OF 110W.

...DISCUSSION...
A LONG WAVE TROUGH DOMINATES WESTERN N AMERICA WITH ITS MEAN 
AXIS CONTINUING SW INTO THE DISCUSSION AREA FROM 32N115W TO A 
BASE AT 12N120W. TWO AREAS OF UPPER MOISTURE ARE ROTATING 
THROUGH THE UPPER PATTERN WITH THE EASTERN MOST AREA COVERING 
ARIZONA AND NEW MEXICO...BUT SEEMS TO BE EVAPORATING WITH TIME. 
A SECOND AREA OF MOISTURE IS W OF THE UPPER TROUGH AXIS...AND IS 
SHIFTING SE OVER THE DISCUSSION AREA TO THE N OF 28N BETWEEN 
122W AND 130W. IMMEDIATELY TO THE S IS A BAND OF VERY DRY UPPER 
AIR...ROUGHLY WITHIN 120 NM EITHER SIDE OF A LINE FROM 32N136W 
TO 25N122W WHERE IT TURNS NE ACROSS THE NORTHERN BAJA CALIFORNIA 
PENINSULA AND THE GULF OF CALIFORNIA.

AN UPPER LEVEL CYCLONE CONTINUES OVER THE DEEP TROPICS NEAR 
04N107W AND SEPARATES THE UPPER ANTICYCLONIC FLOW. TO THE W AN 
UPPER ANTICYLONE IS CENTERED NEAR 02S145W WITH A SHORT WAVE 
RIDGE EXTENDING N TO A CREST NEAR 25N135W. AN UPPER ANTICYCLONE 
IS CENTERED NEAR 13N94W WITH A RIDGE AMPLIFYING N ACROSS THE 
CENTRAL GULF OF MEXICO. UPPER DIFFLUENCE IS ENHANCING THE 
PREVIOUSLY DESCRIBED CONVECTION ALONG THE TWO LOW LEVEL TROUGHS. 
THE RESULTANT DEBRIS MOISTURE IS ADVECTED NE MERGING WITH A 
DENSE TROPICAL PLUME THAT ORIGINATES IN THE CENTRAL PACIFIC. THE 
DENSE PLUME IS WITHIN 240 NM OF LINE 19N140W TO 17N119W...
THEN CONTINUES NE ACROSS CENTRAL OLD MEXICO TO OVER THE W 
CENTRAL GULF OF MEXICO. DEBRIS MOISTURE FROM THE CONVECTION S OF 
PANAMA EVAPORATES IN THE DRY UPPER AIR THAT DOMINATES THE 
TROPICS S OF 17N E OF 105W.

AT THE LOW LEVELS A RIDGE EXTENDS FROM 32N140W TO 15N110W. A 
COLD FRONT IS NE OF THE RIDGE FROM 30N116W TO 25N127W TO 29N140W 
AND ACCOMPANIED BY NORTHERLY WINDS AT 15 TO 20 KT AND COMBINED 
SEAS TO 10 FT IN NW SWELL. THESE NORTHERLY WINDS SHOULD SPREAD 
SE TO ALONG THE WESTERN BAJA CALIFORNIA PENINSULA THROUGH TUE. S 
OF THE RIDGE NE TO E TRADE WINDS CONTINUE AT 15 TO 20 KT WITH 
SEAS 9 TO 11 FT PRIMARILY IN MIXED NE AND NW SWELL. ALTHOUGH 
WINDS ARE LIGHT...MIXED N SWELL CONTINUES TO PROPAGATE SE OVER 
THE REMAINDER OF THE AREA NW OF LINE FROM 23N110W TO 07N130W TO 
07N140W...RESULTING IN COMBINED SEAS OF 8 TO 11 FT PRIMARILY IN 
THE MIXED N SWELL. SOUTHERLY SWELL..WITH SEAS TO 8 FT...IS NOTED 
OVER THE AREA S OF 08N BETWEEN 95W AND 115W. THIS SOUTHERLY 
SWELL WILL SPREAD A LITTLE FURTHER N OVER THE NEXT FEW DAYS 
MIXING WITH THE REINFORCED N SWELL BEHIND THE COLD FRONT.

GULF OF CALIFORNIA...SW WINDS ARE INCREASING TO 15 TO 20 KT OVER 
THE NORTHERN WATERS AHEAD OF THE COLD FRONT. NORTHERLY WINDS AT 
15 TO 20 KT ARE FORECAST TO PERSIST THROUGH TUE OVER THE GULF 
WATERS TO S OF 29N IN THE WAKE OF THE COLD FRONT. NW WINDS WILL 
THEN INCREASE TO 20 TO 30 KT WED INTO THU. 

GULF OF TEHUANTEPEC...A STRONG COLD FRONT IS EXPECTED TO MOVE 
THROUGH THE GULF OF MEXICO WED. NORTHERLY WINDS AT 15 TO 20 KT 
WILL SURGE INTO THE GULF OF TEHUANTEPEC AS EARLY AS LATE WED
POSSIBLY INCREASING TO GALE FORCE AROUND SUNRISE THU.

$$
MUNDELL