000
AXPZ20 KNHC 230924
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE SEP 23 2008

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0845 UTC.

...TROPICAL WAVES...

TROPICAL WAVE ALONG 84W N OF 05N IS MOVING W 15 KT. THERE IS 
VERY LITTLE EVIDENCE OF THIS FEATURE AND THEREFORE ITS CURRENT 
POSITION IS BASED MAINLY ON EXTRAPOLATION. 

TROPICAL WAVE EXTENDS ACROSS THE GULF OF TEHUANTEPEC ALONG 94W N 
OF 06N MOVING W 10-15 KT. A LARGE CLUSTER OF STRONG CONVECTION 
IS OBSERVED ALONG OR JUST W OF THE WAVE AXIS N OF 13N BETWEEN 
94W-97W...STEERED BY STRONG MID-UPPER NE/E FLOW. SCATTERED 
CONVECTION LIES NEAR THE INTERSECTION OF THE ITCZ. WHILE 
SHORTWAVE IR IMAGES REVEAL MID-LEVEL CYCLONIC TURNING NEAR 
12N92W...THERE IS NO INDICATION OF A SFC LOW AS SCATTEROMETER 
AND SHIP DATA SUGGEST UNIFORM SW TO W FLOW. THE WAVE IS EXPECTED 
TO REMAIN IN A STRONGLY SHEARED ENVIRONMENT OVER THE NEXT DAY OR 
TWO WHICH SHOULD LIMIT DEVELOPMENT. 

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 09N85W 08N105W 09N120W 07N140W. 
SCATTERED MODERATE CONVECTION IS WITHIN 240 NM S OF THE AXIS 
BETWEEN 91W AND 95W. 

...DISCUSSION...

W OF 110W...
THE MID AND UPPER PATTERN CONSISTS OF AN UPPER HIGH OVER THE 
TROPICS NEAR 18N130W...ANOTHER HIGH JUST N OF THE AREA NEAR 
32N128W...AND AN UPPER TROUGH OVER THE BAJA PENINSULA. 
WIDESPREAD DRY STABLE AIR IS ASSOCIATED WITH THIS PATTERN 
ALLOWING FOR TRANQUIL WEATHER CONDITIONS. AT THE SFC...A 1025 MB 
HIGH IS CENTERED NEAR 35N135W AND A QUASI-STATIONARY 1010 MB LOW 
IS SITUATED WITHIN THE ITCZ NEAR 11N122W. THERE IS ENOUGH OF A 
PRES GRADIENT BETWEEN THESE FEATURES TO PRODUCE 20 KT NE TRADES 
OVER THE W WATERS. SIMILAR MAGNITUDE N TO NW WINDS ARE OFF THE 
BAJA COAST N OF 29N BETWEEN 120W-124W...BUT EXPECTED TO DIMINISH 
SHORTLY. S TO SW SWELLS (16-18 SEC PERIODS) ARE BEGINNING TO 
SPREAD N OF THE EQUATOR BETWEEN 115W AND 133W. THESE SWELLS WILL 
ELEVATE SEAS TO 9 FT MAINLY S OF 10N E OF 130W OVER THE NEXT 
COUPLE OF DAYS.

E OF 110W...
A BROAD AREA OF LOW PRESSURE CENTERED A COUPLE HUNDRED NM SSW OF 
MANZANILLO MEXICO NEAR 16N107W HAS BEEN WEAKENING CONSIDERABLY. 
WHILE SATELLITE IMAGERY DOES SHOW A FAIRLY WELL DEFINED 
CIRCULATION...CONVECTION IS LIMITED TO A NARROW BAND WITHIN 180 
NM W OF THE ESTIMATED CENTER. AN ASCAT PASS AROUND 05Z SHOWED 
ONLY A SMALL AREA OF WINDS TO 20 KT MAINLY W OF THE CENTER. 
ELSEWHERE...WATER VAPOR IMAGERY DEPICTS WIDESPREAD MOISTURE OVER 
THE REGION. THIS MOISTURE IS BEING DEEPENED BY THE TROPICAL WAVE 
ALONG 94W...DISCUSSED ABOVE.  

$$
CANGIALOSI