000
AXPZ20 KNHC 060335
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI NOV 06 2009

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0315 UTC.

...TROPICAL LOW...

.LOW PRES IS CENTERED NEAR 11N92W ESTIMATED AT 1009 MB AND IS 
NEARLY STATIONARY. THE SYSTEM IS ENCOUNTERING SOUTHWESTERLY WIND 
SHEAR. CURRENTLY SCATTERED MODERATE AND ISOLATED STRONG 
CONVECTION IS NOTED WITHIN 30 NM 11.5N92W...WITH THE CONVECTION 
OCCASIONALLY BANDING MAINLY NW OF THE CENTER. 

...ITCZ...

THE ITCZ AXIS EXTENDS ALONG 12N85W TO 08N99W TO 13N114W TO 
08N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED 
WITHIN 30 NM EITHER SIDE OF A LINE FROM 07N97W TO 08N103W AND 
WITHIN 150 NM OF 09N110W AND 14N115W AND 10N129.5W. 

...DISCUSSION...

AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 12N115W WITH A SHORT 
WAVE RIDGE AMPLIFYING N TO A CREST NEAR 34N114W MERGING INTO A 
LONG WAVE RIDGE THAT HAS ITS MEAN AXIS N TO S ALONG ROUGHLY 110W 
OVER ALL OF N AMERICA. A TROPICAL RIDGE EXTENDS SW FROM THE 
ANTICYCLONE TO A SHARP CREST OVER THE ITCZ AT 10N133W WITH 
ANOTHER RIDGE EXTENDING SE FROM THE ANTICYCLONIC CENTER TO 
11N104W. UPPER LEVEL DIFFLUENCE IS ENHANCING ITCZ CONVECTION 
BETWEEN 120W AND 134W WITH THE RESULTANT DEBRIS MOISTURE 
ADVECTED NE ALONG THE W PERIPHERY OF THIS TROPICAL RIDGE... 
ROUGHLY WITHIN 150 NM EITHER SIDE OF LINE 13N125W TO 24N116W 
WHERE THE MOISTURE TURNS SE TO NEAR 17N106W. ANOTHER BRANCH OF 
MOISTURE IS ALSO ADVECTED N ALONG 116W TO SOUTHERN CALIFORNIA.
UPPER DIFFLUENCE IS ALSO ENHANCING CONVECTION NEAR 13N115W 
WITH THE MOISTURE TRAPPED IN THE SAME AREA. CONVECTION ALONG THE 
ITCZ BETWEEN 103W AND 112W WAS ALSO ENHANCED SOME EARLIER 
WITH THE DEBRIS MOISTURE SPREADING SW TO ALONG 03N.

TO THE NW OF THE ANTICYCLONE...AN UPPER SHORTWAVE TROUGH HAS 
MOVED INTO THE AREA WITH ITS MEAN AXIS N OF 20N ALONG 127W. 
UPPER MOISTURE IS NOTED N OF 24N E OF 128W TO OVER THE NORTHERN 
BAJA PENINSULA.

AN UPPER TROUGH EXTENDS S INTO THE DISCUSSION AREA ALONG 32N96W 
TO 22N97W AND INTO A SMALL UPPER CYCLONE AT 19N96W WITH THE 
TROUGH CONTINUING S TO A BASE OVER THE DEEP TROPICS AT 11N99W. 
CONVECTION IS SLIGHTLY ENHANCED ALONG THE ITCZ JUST E OF THIS 
TROUGH...BETWEEN 92W AND 96W WITH MOST OF THE DEBRIS MOISTURE 
SPREADING N ACROSS GUATEMALA AND EASTERN OLD MEXICO EVENTUALLY 
TURNING NE INTO A PLUME THAT CONTINUES ACROSS FLORIDA AND INTO 
THE CENTRAL ATLC. THE DEBRIS MOISTURE MERGES WITH THE MOISTURE 
FROM TROPICAL STORM IDA OVER NICARAGUA.

AT THE LOW LEVELS...A SURFACE HIGH PRES IS NEAR 26N122W 1020 MB. 
AN INITIAL COLD FRONT IS LOSING ITS PUSH ALONG 32N131W TO 
24N140W WHILE A SECONDARY FRONT IS RAPIDLY APPROACHING THE 
EXTREME NW PORTION OF THE AREA. ALTHOUGH ASSOCIATED WINDS HAVE 
DIMINISHED BELOW 20 KT THE FRONTS ARE ACCOMPANIED BY NW SWELLS 
THAT WILL CONTINUE TO BUILD TO NEAR 18 FT LATE SAT ALONG 30N 
BETWEEN 125W AND 135W.

GAP WINDS...
GALE FORCE WINDS ARE EXPECTED TO CONTINUE THROUGH THE GULF OF 
TEHUANTEPEC THROUGH FRI DIMINISHING BELOW GALE FRI NIGHT. SOME 
UNCERTAINTY IN THE FORECAST AS GUIDANCE SUGGESTS ANOTHER GALE N 
OF THE AREA IN THE BAY OF CAMPECHE AND DEPENDING ON THE 
ORIENTATION OF THE GALE CENTER IT MAY CONTRIBUTE TO ANOTHER   
N SURGE IN THE GULF OF TEHUANTEPEC OR ACTUALLY IMPEDE N FLOW 
INTO THE ISTHMUS OF TEHUANTEPEC. TO FURTHER COMPLICATE THE 
FORECAST IS CONSIDERABLY UNCERTAINTY WITH THE FUTURE OF TROPICAL 
CYCLONE IDA.

$$
NELSON