000
AXPZ20 KNHC 041558
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON OCT 04 2010

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.

...ITCZ...

AXIS FROM 10N86W TO 09N97W TO LOW PRES AT 09N105W 1009 MB TO 
12N128W TO 11N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION N OF LINE FROM 04N77W TO 08N88W TO THE COAST OF 
CENTRAL AMERICA. SCATTERED MODERATE NOTED WITHIN 90 NM SE 
QUADRANT OF LOW PRES AT 09N105W. 

...DISCUSSION...

ALOFT...A NEGATIVE TILT UPPER TROUGH LIES PARALLEL TO THE SW 
COAST CONUS WITH THE SOUTHERN PORTION EXTENDING INTO THE 
DISCUSSION AREA ALONG 32N120W TO A BASE AT 28N116W. AN UPPER 
LEVEL ANTICYCLONE IS STATIONARY NEAR 18N117W WITH A RIDGE 
EXTENDING W TO A CREST AT 15N134W. AN UPPER RIDGE ALSO EXTENDS
N AND IS AMPLIFYING OVER NEW MEXICO TO BEYOND 32N106W. A 
POSITIVE TILT LONG WAVE TROUGH DOMINATES EASTERN N AMERICA WITH 
ITS SOUTHERN EXTENSION EXTENDING SW ACROSS THE GULF OF MEXICO 
AND CENTRAL OLD MEXICO INTO A SMALL NEARLY STATIONARY UPPER 
CYCLONE OVER THE PACIFIC COAST OF OLD MEXICO AT 22N105W. THE 
UPPER TROUGH THEN CONTINUES SSE OVER THE E PACIFIC TO A BASE AT 
13N102W. CONVECTION WAS ENHANCED EARLIER NEAR 21N105W WITH THE 
DEBRIS MOISTURE EVAPORATING IN THE SAME AREA. SOME UPPER 
MOISTURE IS NOTED WITHIN 150 NM OF 12N134W. A FEW TSTMS FLARED 
NEAR 15.5N116W WITH THE DEBRIS NEARLY EVAPORATED.  OTHERWISE... 
THE UPPER LEVELS ARE DRY W OF 110W. 

AN UPPER RIDGE EXTENDS W ACROSS THE CARIBBEAN AND CENTRAL 
AMERICA ALONG 13N TO A FAIRLY SHARP CREST AT 10N103W. THE 
ASSOCIATED UPPER DIFFLUENCE S OF THIS UPPER RIDGE HAS BEEN 
ENHANCING SIGNIFICANT CONVECTION OVER THE SOUTHERN CARIBBEAN AND 
COLOMBIA AND SPORADIC CONVECTION ALONG THE E PACIFIC ITCZ. THE 
RESULTANT DEBRIS MOISTURE FROM THIS CONVECTION HAS BEEN 
SPREADING WESTWARD OVER THE TROPICAL PACIFIC...BUT REMAINS UNDER 
THE UPPER RIDGE.

AT THE LOW LEVELS A RIDGE EXTENDS FROM 32N142W TO 22N115W. LONG 
PERIOD NW SWELLS AT 9 TO 12 SECONDS ARE PRODUCING COMBINED SEAS 
TO 10 FT OVER THE AREA NW OF A LINE FROM 32N115W TO 10N128W TO 
10N140W.  

GAP WINDS...MINIMAL GALE FORCE WINDS ARE OCCURRING IN AND 
DOWNSTREAM OF THE GULF OF TEHUANTEPEC AND ARE EXPECTED TO 
PERSIST FRO 48 HOURS.

$$
NELSON