000
AXPZ20 KNHC 030315
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED OCT 03 2012

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS W ALONG 10.5N FROM NW COLOMBIA AT 
10N76W ACROSS NORTHERN COSTA RICA TO 11N86W T0 13N103W. THE 
MONSOON TROUGH RESUMES SW OF THE REMNANTS OF MIRIAM NEAR 14N117W 
TO 11N128W WHERE LOW LEVEL WINDS INDICATE A TRANSITION TO AN 
ITCZ WHICH CONTINUES W TO 09N140W. ISOLATED MODERATE TO STRONG 
CONVECTION IS OBSERVED FROM 05N TO 10N E OF 87W. SCATTERED 
MODERATE AND ISOLATED STRONG CONVECTION IS NOTED N OF 08N 
BETWEEN 92W AND 105W...AND WITHIN 60 NM EITHER SIDE OF LINES
09N105W TO 09N112W TO 11N114W...FROM 11N118W TO 08N126W...AND 
FROM 11N130W TO 09N135W.

...DISCUSSION...

AN UPPER LEVEL CYCLONE IS AT 32N135W WITH AN UPPER TROUGH 
EXTENDING S THROUGH 20N135W TO A BASE OVER THE DEEP TROPICS AT 
13N135W. AN UPPER ANTICYCLONE IS AT 28N116W WITH A RIDGE 
EXTENDING N BEYOND 32N119W. A SECOND UPPER RIDGE EXTENDS SW TO A 
CREST OVER THE TROPICS AT 16N131W. UPPER CYCLONES ARE AT 01N138W 
AND 04N123W. WEAK UPPER DIFFLUENCE IS NOTED BETWEEN THESE UPPER 
FEATURES SUPPORTING THE CONVECTION ALONG THE MONSOON TROUGH AND 
ITCZ BETWEEN 107W AND 135W. THE RESULTANT DEBRIS MOISTURE FANS 
OUT BOTH TO THE N AND TO THE S BUT SEEMS TO EVAPORATE WITHIN 150 
NM OF THE CLUSTERS AS THE UPPER LEVELS ARE VERY DRY OVER THE 
ENTIRE DISCUSSION AREA W OF 107W. 

AN UPPER CYCLONE OVER EASTERN TEXAS HAS AN UPPER TROUGH 
EXTENDING SW ACROSS THE WESTERN GULF OF MEXICO THEN ACROSS 
CENTRAL MEXICO TO A BASE AT 18N106W. AN UPPER RIDGE EXTENDS NW 
FROM S AMERICA ACROSS THE DEEP TROPICS TO THE S OF 10N E OF 90W 
AND IS ADVECTING UPPER MOISTURE W ACROSS THE DISCUSSION AREA E 
OF 85W. MOISTURE FROM THE CONVECTION PREVIOUSLY DESCRIBED TO THE 
N OF 08N BETWEEN 92W AND 105W IS SPREADING NE ACROSS CENTRAL 
AMERICA AND THE SOUTHEASTERN GULF OF MEXICO EVENTUALLY MERGING 
WITH ANOTHER PLUME OF MOISTURE SPREADING N ACROSS THE EASTERN 
GULF OF MEXICO.

ELSEWHERE AT THE LOW LEVELS...A BROAD SURFACE RIDGE COVERS THE 
AREA N OF 20N W OF 120W. THE REMNANT TROUGH OF MIRIAM EXTENDS 
FROM 19N117W TO 14N118W. 

SW LOW LEVEL WINDS AT 15 TO 20 KT AND CROSS EQUATORIAL SOUTHERLY 
SWELL COMBINE RESULTING IN SEAS TO 9 FT IN THE AREA FROM 05N TO 
10N BETWEEN 99W AND 122W. THE WINDS ARE EXPECTED TO DIMINISH TO 
15 KT AND THE SEAS SUBSIDE TO LESS THAN 8 FT BY LATE THU.

GAP WINDS...HIGH PRES BUILDING IN THE WAKE OF A GULF OF MEXICO 
STALLED FRONT HAS ALREADY SURGED AT 20 TO 30 KT INTO AND 
DOWNSTREAM OF THE GULF OF TEHUANTEPEC WITHIN 45 NM EITHER SIDE 
OF LINE FROM 16N94.5W TO 14N97W TO 13.5N98.5W...WITH SEAS 8 TO 
11 FT. THE AREA OF NE TO E WINDS WILL EXPAND W ACROSS THE AREA 
FROM 11.5N TO 15N BETWEEN 96.5W AND 106W THROUGH THU. THE 
GRADIENT WILL ALSO INCREASE OVER THE W CENTRAL CARIBBEAN SURGING 
INTO AND DOWNSTREAM OF THE GULF OF PAPAGAYO AT 20 TO 25 KT 
BEGINNING WED NIGHT AND CONTINUING THROUGH THU.

$$
NELSON