000
AXPZ20 KNHC 100958
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN OCT 10 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 
0945 UTC.

...THE ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ANALYZED FROM 09N84W TO 
07N90W TO 1011 MB LOW PRES AT 08N118W. THE ITCZ THEN TURNS NW TO 
A SECOND 1010 MB LOW PRES NEAR 11N129W WITH THE AXIS CONTINUING 
SW TO 08N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION 
NOTED WITHIN 90 NM OF THE PACIFIC COAST OF COLOMBIA...AND 
WITHIN 15 NM EITHER SIDE OF A LINE FROM 08N92W TO 08N95W...AND 
WITHIN 15 NM OF 08N101W...AND ALSO WITHIN 120 NM EITHER SIDE OF 
A LINE FROM 11N128W TO 11N134W TO 09N140W.

...DISCUSSION...

AN UPPER TROUGH EXTENDS ALONG 32N109W TO 27N119W TO 23N140W INTO 
AN UPPER CYCLONE W OF THE AREA NEAR 21N145W. THIS UPPER CYCLONE 
IS EXPECTED TO CUT OFF AND DRIFT NEAR 24N140W FOR A FEW DAYS 
WHILE A SECOND UPPER CYCLONE MAY DEVELOP ALONG THE TROUGH NEAR 
28N122W. TO THE N OF THIS UPPER TROUGH IS AN UPPER ANTICYCLONE 
AT 32N128W WITH A RIDGE EXTENDING SW TO 29N140W. UPPER MOISTURE 
IS NOTED WITHIN THE RIDGE.

AN UPPER TROUGH EXTENDS N TO S FROM 22N124W TO 13N122W TO 
05N118W. A TROPICAL ANTICYCLONE IS NOTED NEAR 03N138W WITH BROAD 
ANTICYCLONIC FLOW DOMINATING THE AREA S OF 20N W OF 125W. THE 
ASSOCIATED UPPER DIFFLUENCE IS ENHANCING CONVECTION ALONG THE 
ITCZ AXIS AS PREVIOUSLY DESCRIBED. DEBRIS MOISTURE FROM THIS 
CONVECTION...AND UPPER DEBRIS MOISTURE STREAMING IN FROM 
CONVECTION W OF THE DISCUSSION AREA...COMBINE TO MAKE THE UPPER 
LEVELS MOIST FROM 07N TO 15N BETWEEN 125W AND 140W. 
   
AN UPPER ANTICYCLONE NEAR PUERTO RICO HAS A RIDGE EXTENDING W 
ACROSS CENTRAL AMERICA ALONG 13N TO A CREST OVER THE TROPICAL 
PACIFIC AT 13N117W. ALTHOUGH THE ASSOCIATED UPPER DIFFLUENCE IS 
ENHANCING SIGNIFICANT CONVECTION OVER THE W CARIBBEAN...ONLY A 
FEW CONVECTIVE CLUSTERS ARE NOTED WITHIN THE DISCUSSION AREA
ALONG THE PACIFIC COAST OF COLOMBIA AND NEAR 08N92W. THE 
RESULTANT DEBRIS MOISTURE IS NOTED N OF 07N E OF 87W. 
OTHERWISE...THE UPPER LEVELS ARE VERY DRY N OF 23N AND S OF 23N 
E OF 110W.

ELSEWHERE AT THE LOW LEVELS...HIGH PRES IS CENTERED NEAR 31N132W 
1025 MB WITH A RIDGE SW TO BEYOND 28N140W...AND A RIDGE SE TO 
NEAR 15N110W. THE GRADIENT S OF THIS SURFACE RIDGE AND N OF THE 
ITCZ IS SUPPORTING NE TO E TRADES AT 20 KT WITH SEAS TO ABOUT 11 
FT IN MIXED SWELL. THE PARENT SURFACE HIGH IS EXPECTED TO SHIFT 
N OF THE AREA...SOMEWHAT BLOCKING THE NEXT COLD FRONT...AND 
ALLOWING THE NE WINDS TO INCREASE TO 15 TO 20 KT OVER THE   
ENTIRE AREA W OF 123W BY MON.

GAP WINDS...NORTHERLY WINDS AT 20 TO 25 KT ARE NOTED OVER AND 
DOWNSTREAM OF THE GULF OF TEHUANTEPEC TO NEAR 13N97W. EXPECT
THESE WINDS TO DIMINISH TO 15 TO 20 KT BY LATER TODAY WITH 
LITTLE CHANGE THROUGH MON. HIGH PRES WILL SHIFT TO OVER THE N 
CENTRAL GULF OF MEXICO TUE NIGHT WITH NORTHERLY WINDS INCREASING 
TO 20 KT LATE TUE NIGHT IN THE GULF OF TEHUANTEPEC AND FURTHER 
UNCEASING TO 20 TO 25 KT AROUND SUNRISE WED. 
 
$$
NELSON