000
AXPZ20 KNHC 291503
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI SEP 29 2006

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

ITCZ...
AXIS IS CENTERED ALONG 9N84W 8N107W 13N124W 11N132W 10N140W. 
SCATTERED MODERATE CONVECTION IS WITHIN 240 NM MAINLY TO SOUTH 
OF THE AXIS E OF 95W. ISOLATED MODERATE IS WITHIN 180 NM EITHER 
SIDE OF THE AXIS BETWEEN 109W-119W.

TROPICAL WAVES/LOWS...
A TROPICAL WAVE IS ALONG 88W N OF 3N EXTENDING ACROSS CENTRAL 
AMERICA MOVING W 10 TO 15 KT OVER THE PAST 24 HOURS. CONVECTION 
ASSOCIATED WITH THIS WAVE HAS BEEN PULSING OVER THE LAST FEW 
DAYS...MAKING THIS FEATURE TRACKABLE ON HOVMOLLER DIAGRAMS. 
SCATTERED MODERATE CONVECTION IS MAINLY IN THE ITCZ EXCEPT FOR A 
PATCH FROM 12N-13N BETWEEN 89W-91W.

A 1010 MB LOW IS CENTERED NEAR 13N130W MOVING W 10 TO 15 KT.  
THIS LOW HAS WEAKENED TO A SWIRL OF LOW CLOUDS AS PREDICTED BY 
MOST OF THE GLOBAL MODELS. IT IS CAUSING A SLIGHT NORTHWARD 
PERTURBATION IN THE ITCZ. 

...DISCUSSION...
THE MID TO UPPER LEVEL TROUGH THAT HAS COVERED THE NW PORTION OF 
THE AREA MUCH OF THIS WEEK CONTINUES TO WEAKEN AND LIFT TO THE 
NE OF THE AREA. THE AXIS CURRENTLY EXTENDS FROM AN UPPER LOW 150 
NM W OF THE NRN CALIFORNIA COAST TO ANOTHER UPPER LOW NEAR 
31N141W. MID-UPPER LEVEL RIDGING HAS STRENGTHENED S OF THE 
TROUGH ANCHORED BY A SPRAWLING ANTICYLONE NEAR 15N133W AND A 
SMALLER WEAKENING ANTICYLONE OFF THE MEXICAN COAST NEAR 20N110W. 
A WEAK TROUGH LIES ALONG THE BAJA AND A LARGE SLOW MOVING UPPER 
LEVEL LOW IS LOCATED TO THE SE OF THE RIDGE NEAR 8N106W. THIS 
PATTERN IS PRODUCING A FAIR AMOUNT OF HIGH LEVEL MOISTURE ACROSS 
THE AREA EXCEPT FOR A DRY SLOT WITHIN 180 NM OF A LINE FROM 
10N140W TO 20N122W. HOWEVER...MOST OF THE MOISTURE IS NOT DEEP 
IN NATURE WITH CONVECTION LIMITED TO THE ITCZ AND SHALLOW AND 
ISOLATED WITHIN 300 NM OF THE UPPER LOW. 

AT THE SFC...A 1028 MB HIGH IS CENTERED NEAR 40N140W. FRESH 
TRADES CONTINUE BETWEEN THIS HIGH PRESSURE AND LOW PRES TO THE 
S. AN 1134 UTC QUIKSCAT PASS SHOWED GAP WINDS TO 20 KT IN THE 
TEHUANTEPEC AREA LIKELY ENHANCED BY THE NEARBY TROPICAL WAVE. 
HOWEVER...THEY PROBABLY WILL NOT INCREASE MUCH IN THE SHORT TERM 
AS HIGH PRESSURE WEAKENS TO THE NORTH AHEAD OF A COLD FRONT 
ENTERING THE NORTHERN GULF OF MEXICO. 

$$
CANGIALOSI