000
AXPZ20 KNHC 241524
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED SEP 24 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.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 89W/90W N OF 05N MOVING W 10-15 KT. THIS 
WAVE IS GENERATING SOME CLOUDINESS WITH EMBEDDED SHOWERS OVER 
NORTHERN CENTRAL AMERICA.  

TROPICAL WAVE IS ALONG 98W N OF 07N MOVING W 10 KT. A 1008 MB 
SURFACE LOW IS ALONG THE WAVE AXIS NEAR 12N. THE COMBINATION OF 
THE WAVE AND THE SFC LOW IS PRODUCING A LARGE AREA OF SCATTERED 
MODERATE CONVECTION FROM 11N-16N BETWEEN 95W-102W. GLOBAL MODELS 
DO SUGGEST SFC LOW PRES DEVELOPMENT BUT IT WILL LIKELY BE 
LIMITED SOME DUE TO MODERATE TO STRONG UPPER ELY WINDS.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 08N80W 12N94W 10N110W 08N130W  
08N140W. MOST OF THE CONVECTIVE ACTIVITY IS ASSOCIATED WITH THE 
TROPICAL WAVES/LOWS LOCATED ACROSS THE FORECAST AREA. SCATTERED 
MODERATE CONVECTION IS NEAR 8N130W.  

...DISCUSSION...

E OF 115W...
A LOW PRESSURE AREA LOCATED SEVERAL HUNDRED MILES SOUTH OF THE 
SOUTHERN TIP OF BAJA CALIFORNIA HAS BEEN TRACKED FOR THE PAST 
SEVERAL DAYS. AT 24/1200 UTC THE SFC LOW IS NEAR 16.5N110.5W. 
SHOWER AND THUNDERSTORM ACTIVITY ASSOCIATED WITH THIS FEATURE 
REMAIN LIMITED AND POORLY ORGANIZED. CURRENTLY...SATELLITE 
IMAGERY SHOWS A CLUSTER OF MODERATE TO ISOLATED STRONG 
CONVECTION WITHIN 115 NM NW QUADRANT OF LOW CENTER. THIS LOW IS 
FORECAST TO MOVE MAINLY WWD INTO A VERY STABLE ATMOSPHERE...SO 
SIGNIFICANT DEVELOPMENT OF THIS SYSTEM IS NOT EXPECTED.

A MID TO UPPER HIGH OVER SOUTH-CENTRAL MEXICO CONTINUES TO 
PROVIDE NE/E FLOW AND CONSIDERABLE MOISTURE E OF 110W. WHILE THE 
ATMOSPHERE IS VERY MOIST...CONVECTION IS CONFINED TO THE 
TROPICAL WAVE LOCATED ALONG 98W. 

W OF 115W...
THE SFC PATTERN HAS CHANGED LITTLE OVER THE PAST FEW DAYS WITH 
HIGH PRES CENTERED NW OF THE FORECAST AREA AND A NEARLY 
STATIONARY 1011 MB SFC LOW EMBEDDED WITHIN THE ITCZ NEAR 
10N124W. CONVECTION HAS SLIGHTLY INCREASE ON THE WEST SIDE OF 
THE LOW...AND IS FORECAST TO OPEN INTO A TROUGH OVER THE NEXT 
DAY OR TWO. THE PRES GRADIENT BETWEEN THESE FEATURES CONTINUES 
TO SUPPORT 20 KT NE TRADES FROM 14N-17N W OF 130W. IN THE MID 
AND UPPER LEVELS...WIDESPREAD DRY STABLE AIR EXISTS OVER THIS 
ENTIRE REGION JUST N OF THE ITCZ AXIS. AN UPPER-LEVEL LOW IS 
SPINNING OVER THE FAR NW CORNER OF THE DISCUSSION AREA.  

CROSS-EQUATORIAL SLY SWELL...WITH PERIODS OF 16-18 SECONDS...HAS 
ELEVATED SEAS TO 8 FT S OF 08N BETWEEN 105W AND 130W. THIS SWELL 
TRAIN WILL CONTINUE NNE TOWARD THE COAST OF MEXICO/CENTRAL 
AMERICA DURING THE DAY TODAY AND GRADUALLY DIMINISH THU AND FRI.

$$
GR/JC