000
AXPZ20 KNHC 291554
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON SEP 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 1515 UTC.

...SPECIAL FEATURES...

A SURFACE LOW PRESSURE SYSTEM NEAR 11N95W HAS THE POTENTIAL TO 
BECOME A TROPICAL CYCLONE WITHIN THE NEXT 48 HOURS AS IT SLOWLY 
DRIFTS TO THE WNW.  THIS LOW IS ASSOCIATED WITH THE TROPICAL 
WAVE ALONG 96W N OF 04N. A DEEP TROUGH ACROSS THE GULF OF MEXICO 
INTO THE BAY OF CAMPECHE IS FUNNELING ENERGY SOUTHWARD INTO THE 
GULF OF TEHUANTEPEC AND ADJACENT PACIFIC WATERS ENHANCING 
SURFACE CYCLONIC TURNING NEAR THE PACIFIC LOW. PRESENTLY 
CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE 
FROM 13N-15N BETWEEN 96W-98W...FROM 10N-12N BETWEEN 
95W-99W...AND FROM 7N-10N BETWEEN 92W-95W. 

...TROPICAL WAVES...

TROPICAL WAVE ALONG 86W/87W N OF 03N IS MOVING W ABOUT 10 KT. 
WIDELY SCATTERED MODERATE CONVECTION IS MOSTLY ALONG THE ITCZ 
FROM 7N-12N BETWEEN 84W-90W. 

TROPICAL WAVE N OF 04N ALONG 96W WITH AN ASSOCIATED 1006 MB 
LOW NEAR 11N95W. THIS WAVE IS MOVING W 5 KT. ASIDE FROM THE 
CONVECTION MENTIONED ABOVE IN THE SPECIAL FEATURE SECTION... 
SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION CAN BE FOUND 
W OF THE WAVE AXIS FROM 07N-13N BETWEEN 96W-101W.

TROPICAL WAVE IS REPOSITIONED TO BE ALONG 112W FROM 06N TO 18N 
MOVING W AROUND 10 KT. A SMALL AREA OF SCATTERED MODERATE 
CONVECTION IS E OF THE WAVE AXIS FROM 16N-19N BETWEEN 107W-110W. 
A VERY LARGE AREA OF SCATTERED MODERATE TO ISOLATED STRONG 
CONVECTION IS W OF THE WAVE AXIS FROM 09N-17N BETWEEN 112W-120W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 10N86W TO 13N105W TO 10N120W TO 
12N137W TO 11N140W. BESIDES THE CONVECTION ALREADY MENTIONED IN 
THE SPECIAL FEATURE AND TROPICAL WAVE SECTIONS...SCATTERED 
MODERATE CONVECTION IS S OF PANAMA FROM 05N-08N BETWEEN 78W-84W. 
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 07-10N 
BETWEEN 101W-104W. IN IN ADDITION SCATTERED MODERATE CONVECTION 
LIES FROM 07N-10N BETWEEN 120W-128W...AND FROM 10N-12N BETWEEN 
132W-135W.

...DISCUSSION...

A COLD FRONT IS APPROACHING THE NW CORNER NEAR 32N140W. 
SCATTERED WEAK CONVECTION IS E OF THE FRONT N OF 28N AND W OF 
138W. A DEEP LAYER TROUGH IS ALSO PUSHING INTO NW WATERS AT THE 
MOMENT AND SHOULD PASS N OF AREA TODAY...ALLOWING THE COLD FRONT 
TO PUSH INTO THE REGION WITH LITTLE SHOWER OR THUNDERSHOWER 
ACTIVITY.  HOWEVER...SW WINDS AHEAD OF THE FRONT ARE EXPECTED TO 
BE IN THE 20 TO 30 KT RANGE AND SEAS WILL BE ELEVATED TO AS HIGH 
AS 12 TO 14 FEET.  

THE UPPER LEVEL RIDGE AXIS EXTENDS FROM THE STATIONARY 
ANTICYCLONE CENTERED S OF BAJA CALIFORNIA NEAR 20N110W WSW TO 
NEAR 15N130W. A REGION OF STRONG SUBSIDENCE LIES BETWEEN THIS 
RIDGE AXIS AND THE DEEP LAYER TROUGH DIGGING INTO NW WATERS. TO 
THE S OF THE RIDGE AXIS...A MEAN MID TO LOW LEVEL TROUGH LIES 
FROM NEAR 15N110W TO 10N140W. THIS IS EXPECTED TO BE A REGION OF 
ACTIVE CONVECTION FOR THE NEXT FEW DAYS. A SURFACE LOW IS TO 
DEVELOP NEAR 15N111W OVER THE NEXT 24 HOURS. FLOW ALOFT 
NEAR THIS LOW SHOULD BECOME PROGRESSIVELY MORE DIFFLUENT OVER 
THE NEXT TWO DAYS.

IN ADDITION TO THE LOW PRESSURE SYSTEM MENTIONED IN THE SPECIAL 
FEATURES SECTION...20 TO 30 KT LOW LEVEL N TO NE FLOW IS PASSING 
THROUGH THE GULF OF TEHUANTEPEC ASSOCIATED WITH THE DEEP LAYER 
TROUGH OVER THE GULF OF MEXICO.  THESE WINDS ARE EXPECTED TO 
CONTINUE FOR THE NEXT FEW DAYS.

ELSEWHERE S OF 06N AND E OF 95W...NE TO N UPPER LEVEL FLOW AT 20 
TO 45 KT WILL INHIBIT DEEP CONVECTION FOR THE NEXT TWO DAYS.

$$
FORMOSA