000
AXPZ20 KNHC 291603
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED OCT 29 2008

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1530 UTC.

...THE ITCZ...
08N79W TO 07N100W TO 12N113W TO 09N122W TO 10N129W TO 08N140W.
NUMEROUS STRONG SHOWERS AND THUNDERSTORMS FROM 09N TO 12N 
BETWEEN 110W AND 116W...AND FROM 07N TO 09N BETWEEN 122W AND 
125W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS
FROM 13N TO 14N BETWEEN 107W AND 108W AND FROM 10N TO 11N 
BETWEEN 129W AND 130W. ISOLATED MODERATE SHOWERS AND POSSIBLE
THUNDERSTORMS FROM 05N TO 10N EAST OF 110W...AND WITHIN 60 NM
ON EITHER SIDE OF THE AXIS WEST OF 130W.

...DISCUSSION...
A DEEP LAYER TROUGH IS PROVIDING THE ATMOSPHERIC SUPPORT
FOR A COLD FRONT THAT IS RIGHT AT THE EDGE OF THE NORTHWESTERN
CORNER OF THE AREA. THIS FRONT IS FORECAST TO MOVE ACROSS THE
AREA DURING THE NEXT 48 HOURS. WINDS OF 20 KT FROM THE NORTHWEST
WILL BE TO THE WEST OF THE FRONT.

A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM A 31N122W CYCLONIC
CIRCULATION CENTER TO 11N125W. A SECOND CENTER THAT IS PART OF 
THE WHOLE AREA OF MIDDLE TO UPPER LEVEL CYCLONIC FLOW IS NEAR
28N116W JUST TO THE WEST OF THE BAJA PENINSULA. A TROUGH EXTENDS
FROM THIS 28N116W CYCLONIC CENTER TO 22N117W TO 16N120W TO 
11N125W.

BROAD UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE AREA
TO THE SOUTH AND SOUTHEAST OF THE ADVANCING DEEP LAYER 
TROUGH/COLD FRONT...TO THE WEST OF THE 31N122W 11N125W TROUGH.

BROAD UPPER LEVEL ANTICYCLONIC WIND FLOW ALSO IS TO THE EAST
OF THE 28N116W 11N125W TROUGH/CYCLONIC FLOW.

A TIGHT SURFACE PRESSURE GRADIENT ACROSS SOUTHERN MEXICO IS 
PRODUCING GALE FORCE WINDS THROUGH THE GULF OF TEHUANTEPEC
NOW AND FORECAST FOR THE NEXT 48 HOURS.

ONE SURFACE TROUGH IS ALONG 113W/114W FROM 08N TO 16N.
THE GFS COMPUTER MODEL FORECASTS AS MUCH AS A 1010 MB LOW
PRESSURE CENTER DURING THE NEXT 24 HOURS...NOT FORECAST
TO PRODUCE 20 KT OF WIND...BUT IN AN AREA OF ALREADY
20 KT PLUS OF WIND.

A SECOND SURFACE TROUGH IS ALONG 127W/129W FROM 07N TO 13N.
NO FORECAST OF 20 KT OF WIND OR SEAS TO 8 FT IS COMING
FROM THIS TROUGH.

$$
MT