000
AXPZ20 KNHC 242140
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED SEP 24 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 
2100 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 90W N OF 05N MOVING W 10-15 KT. THIS WAVE 
IS ONLY GENERATING SOME CLOUDINESS WITH ISOLATED SHOWERS OVER 
NORTHERN CENTRAL AMERICA...PARTICULARLY OVER GUATEMALA.  

TROPICAL WAVE IS ALONG 99W/100W N OF 07N MOVING W 10 KT. A BROAD 
LOW PRES AREA IS ASSOCIATED WITH THE WAVE WHICH IS EMBEDDED IN
LARGE SW MONSOONAL FLOW FOUND THROUGHOUT THE FAR EASTERN PART OF 
THE DISCUSSION AREA. THIS FEATURE IS PRODUCING A LARGE AREA OF 
CLOUDINESS WITH SCATTERED MODERATE CONVECTION WITHIN 180 NM 
EITHER SIDE OF THE WAVE AXIS FROM 12N-16N. GLOBAL MODELS SUGGEST 
THAT A LOW PRES CENTER MAY STILL FORM WITHIN THIS AREA OVER THE 
NEXT 36-48 HOURS BUT IT WILL LIKELY BE LIMITED DUE TO THE 
PRESENCE OF MODERATE TO STRONG UPPER ELY WINDS.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 08N80W 15N98W 10N115W 08N130W  
08N140W. IN ADDITION TO THE CONVECTION ASSOCIATED WITH THE 
TROPICAL WAVES...SCATTERED MODERATE CONVECTION IS WITHIN 100 NM 
S OF AXIS BETWEEN 102W-106W. SIMILAR CONVECTION IS NEAR 8N130W.  

...DISCUSSION...

E OF 115W...
A LOW PRESSURE AREA REMAINS LOCATED SEVERAL HUNDRED MILES SOUTH 
OF THE SOUTHERN TIP OF BAJA CALIFORNIA NEAR 16.5N111.5W. LIMITED 
SHOWER AND THUNDERSTORM ACTIVITY IS ASSOCIATED WITH THIS 
FEATURE. VIS SATELLITE IMAGERY SHOWS A SWIRL OF LOW CLOUDS WITH 
ISOLATED MODERATE CONVECTION WITHIN 180 NM NW QUADRANT OF LOW 
CENTER. THIS LOW IS FORECAST TO MOVE MAINLY WWD INTO A VERY 
STABLE ATMOSPHERE...SO 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 NOW ALONG 99W/100W. 

W OF 115W...
NO MAJOR CHANGE HAS EXPERIENCED THE WEATHER PATTERN ACROSS THIS 
PART OF THE FORECAST AREA WITH HIGH PRES CENTERED NW OF THE 
REGION AND A NEARLY STATIONARY 1010 MB SFC LOW EMBEDDED WITHIN 
THE ITCZ NEAR 10N125W. LIMITED CONVECTION ALSO ACCOMPANIES THIS 
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-19N W OF 130W. IN THE MID AND 
UPPER LEVELS...WIDESPREAD DRY STABLE AIR DOMINATES THIS ENTIRE 
REGION JUST N OF THE ITCZ AXIS. AN UPPER-LEVEL LOW IS SPINNING 
OVER THE FAR NW CORNER OF THE DISCUSSION AREA.  

$$
GR