000
AXPZ20 KNHC 292149
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED OCT 29 2008

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2115 UTC.

...ITCZ...
THE ITCZ AXIS LIES ALONG 06N78W TO 08N87W TO 06N98W TO 11N116W 
TO 08N140W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION 
CAN BE FOUND WITHIN 90 NM S AND 60 NM N OF THE AXIS BETWEEN 115W 
AND 126W. SCATTERED MODERATE CONVECTION LIES N OF THE AXIS E OF 
85W AND ALSO WITHIN 180 NM S AND 90 NM N OF THE AXIS BETWEEN 82W 
AND 105W.

...DISCUSSION...
A DEEP LAYER TROUGH IS PROVIDING THE ATMOSPHERIC SUPPORT FOR A 
SURFACE COLD FRONT THAT HAS MOVED INTO THE NORTHWESTERN CORNER 
OF THE AREA. THIS FRONT IS FORECAST TO MOVE EASTWARD ACROSS 
NORTH WATERS DURING THE NEXT 48 HOURS...DISSIPATING NEAR THE END 
OF THAT PERIOD.  WINDS OF 20 KT FROM THE NORTHWEST WILL BE TO 
THE WEST OF THE FRONT.

A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM A 31N120W CYCLONIC
CIRCULATION CENTER TO 11N125W. A SECOND CENTER THAT IS PART OF 
AN AREA OF MIDDLE TO UPPER LEVEL CYCLONIC FLOW IS NEAR
29N116W JUST TO THE WEST OF THE BAJA PENINSULA. A TROUGH EXTENDS
FROM THIS 29N116W CYCLONIC CENTER TO 22N117W TO 16N120W TO 
11N125W.

A TIGHT SURFACE PRESSURE GRADIENT ACROSS SOUTHERN MEXICO IS 
PRODUCING GALE FORCE WINDS THROUGH THE GULF OF TEHUANTEPEC AND 
WINDS OVER 20 KT IN THE GULF OF PAPAGAYO WHICH ARE FORECAST TO 
CONTINUE FOR THE NEXT 48 HOURS.

A SURFACE TROUGH CURRENTLY LIES ALONG 115W FROM 08N TO 16N. IT 
IS SUPPORTING SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION 
WITHIN 180 NM W AND 330 NM E OF THE TROUGH AXIS ALONG 115W FROM 
09N TO 16N. AT THE MOMENT...THIS SYSTEM LIES IN A REGION OF 
UPPER LEVEL DIFFLUENCE CONDUCIVE TO CONVECTION AND IT IS 
FORECAST TO DEVELOP A SURFACE LOW PRESSURE CENTER BEFORE AN 
APPROACHING UPPER TROUGH MAKES CONDITIONS LESS FAVORABLE FOR 
DEVELOPMENT. 

$$
MT/SCHAUER CLARK