000
AXPZ20 KNHC 290916
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED SEP 29 2010

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 
0900 UTC.

...ITCZ...

AXIS ANALYZED ALONG 11N110W TO LOW PRES 11N119W TO LOW PRES 
12N134W TO 11N140W. NO SIGNIFICANT CONVECTION IS NOTED ALONG THE 
ITCZ.

...DISCUSSION...

E OF 110W...
WINDSAT DATA FROM 02Z AND ASCAT DATA FROM 04Z SHOWED A SWATH OF 
20 TO 25 KT SW TO W WINDS GENERALLY N OF 08N E OF 100W...FLOWING 
INTO THE CENTRAL AMERICAN COAST AND ASSOCIATED WITH A BROAD 
MONSOON GYRE OVER THE NW CARIBBEAN. THE FRESH TO STRONG FLOW 
WILL PERSIST THROUGH MOST OF TODAY...THEN GRADUALLY DIMINISH BY 
LATE IN THE DAY. REPORTS FROM THE SOUTHERN MEXICAN PORT OF 
SALINA CRUZ ON THE COAST OF THE GULF OF TEHUANTEPEC SHOW WINDS 
ARE LIKELY STARTING TO DIMINISH THROUGH THE ISTHMUS OF 
TEHUANTEPEC BEHIND A FRONT THAT PENETRATED THE AREA YESTERDAY. 
THE GAP WINDS WILL RETURN BY EARLY FRI AS A REINFORCING SURGE 
PUSHES THROUGH THE SW GULF OF MEXICO. A WEAK CIRCULATION IS 
EVIDENT OF SATELLITE IMAGERY NEAR 14N92W...POSSIBLY THE REMNANT 
LOW OF MATTHEW ENHANCED BY NORTHERLY FLOW THROUGH THE 
TEHUANTEPEC GAP. THIS FEATURE MAY LINGER FOR ANOTHER COUPLE OF 
DAYS WITH LITTLE CHANCE OF FURTHER DEVELOPMENT. FURTHER 
NORTH...A PERSISTENT LOW PRES 1007 MB IS CENTERED NEAR 18N106W 
WHERE IT HAS BEEN FOR THE PAST SEVERAL DAYS. CONVECTION 
OCCASIONALLY PULSES WITH THIS CIRCULATION BUT NO FURTHER 
DEVELOPMENT IS EXPECTED. JASON ALTIMETER DATA FROM THE PAST 24 
HOURS SHOW SEAS TO 8 FT IN AREAS OF STRONG WINDS. LOOKING AHEAD 
LONG PERIOD NW SWELL IS COMBINING WITH SW SWELL...WITH HEIGHTS 
TO 16 FT...AND WILL REACH THE CENTRAL AMERICAN AND SOUTHERN 
MEXICAN COASTS BY EARLY SAT.


W OF 110W...
A SURFACE LOW 1010 MB WAS NOTED ALONG THE ITCZ NEAR 11N118W 
MOVING SLOWLY ENE WITH NO SIGNIFICANT WIND FLOW ASSOCIATED WITH 
IT. A SECOND SURFACE LOW PRES 1011 MB WAS ANALYZED YESTERDAY 
NEAR 13N134W ALONG THE ITCZ...CORROBORATED BY AN ASCAT PASS FROM 
06Z. WINDS REMAIN FAIRLY LIGHT AROUND THIS LOW...BUT MODERATE TO 
FRESH SE FLOW IS DEPICTED IN THE ASCAT DATA S OF THE ITCZ W OF 
135W. DECAYING CONVECTION TO THE W OF THIS LOW. OTHERWISE...NO 
SIGNIFICANT CONVECTION IS NOTED ALONG THE ITCZ OR ELSEWHERE AS 
DEEP LAYER MOISTURE REMAINS VERY LIMITED. ALOFT A MID TO UPPER 
LEVEL REX BLOCK PATTERN COVERS THE AREA W OF 120W...BLOCKING A 
DEEP LAYER TROUGH THAT HAD PUSHED FROM THE CENTRAL PACIFIC TO NW 
OF HAWAII. THIS WILL RESULT IN LITTLE CHANGE OF THE NEXT 2-3 
DAYS. MEANWHILE 15-17 SEC LONG PERIOD SWELL CONTINUES TO PUSH SE 
FROM THE N CENTRAL PACIFIC IN TO THE DISCUSSION AREA. ALTIMETRY 
DATA SHOWS SEAS BEGINNING TO SUBSIDE FROM A MAX OF 13 FT OVER NW 
WATERS FROM THIS SWELL TRAIN. THIS INITIAL SWELL TRAIN WILL 
CONTINUE TO SPREAD SE ACROSS NW HALF OF THE BASIN AND GRADUALLY 
SUBSIDE. A SECOND SURGE OF NW SWELL WILL REACH FAR NW WATERS 
LATE THU.

$$
CHRISTENSEN