000
AXPZ20 KNHC 312123
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU OCT 31 2013

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...SPECIAL FEATURES...                                          

1008 MB LOW PRES IS NEAR 15N108W...OR ABOUT 300 NM SW OF 
MANZANILLO MEXICO MOVING NNW AT 4 KT. RECENT SCATTEROMETER 
PASSES SHOWED FRESH TO STRONG WINDS WITHIN 300 NM IN THE SE 
SEMICIRCLE OF THE LOW...WHILE AN ALTIMETER PASS JUST CLIPPED THE 
OUTER PORTION OF THE SAME AREA SHOWING 8 TO 9 FT SEAS. THE LOW 
IS FORECAST TO REACH NEAR 17.5N110.5W BY 48 HOURS WITH GRADUALLY 
INCREASING WINDS AND SEAS. ASSOCIATED CONVECTION IS BECOMING 
BETTER ORGANIZED AND THERE IS A HIGH CHANCE FOR DEVELOPMENT INTO 
A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

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

THE MONSOON TROUGH EXTENDS FROM 10N85W TO LOW PRES NEAR   
15N108W TO 08N125W TO 10N132W. THE ITCZ EXTENDS FROM 10N132W   
TO 07N140W. SCATTERED MODERATE CONVECTION IS S OF THE MONSOON 
TROUGH AND N OF A LINE FROM 02N78W TO 04N81W TO 04N85W...AND 
WITHIN 120 NM S OF A LINE FROM 08N87W TO 05N92W. SCATTERED 
MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 150 NM NW    
OF A LINE FROM 16N101W TO 14N106W...WITHIN 240 NM IN THE SW 
SEMICIRCLE OF THE LOW... FROM 09N TO 13N BETWEEN 111W AND 
115W...AND ALSO WITHIN 150 NM SE OF A LINE FROM 12N118W TO 
09N139W.

...DISCUSSION...                                            

BROAD UPPER LEVEL TROUGHING EXTENDS FROM OVER SOUTHERN ARIZONA 
NEAR 32N112W TO A MIDDLE TO UPPER LEVEL LOW CENTERED OVER THE 
NORTHERN WATERS NEAR 27N125W. THE TROUGH AXIS EXTENDS FARTHER W-
SW FROM THE LOW TO 24N135W. THE TROUGHING AND LOW REMAINS 
EMBEDDED WITHIN A VERY DRY AND STABLE AIRMASS WITH AN OVERALL 
RELAXED PRES GRADIENT KEEPING NE TRADES 20 KT OR LESS...AND SEAS 
LESS THAN 8 FT N OF 15N W OF 110W...WITH LITTLE CHANGE IN MARINE 
CONDITIONS EXPECTED DURING THE NEXT 48 HOURS.

THE 1010 MB REMNANT LOW OF RAYMOND IS NEAR 21N115W. FRESH WINDS 
AND SEAS TO 7 FT REMAIN IN THE NW SEMICIRCLE AS INDICATED BY 
RECENT SCATTEROMETER AND ALTIMETER DATA. THIS REMNANT LOW IS 
FORECAST TO GRADUALLY SPIN DOWN DURING THE NEXT 24 HOURS.

OTHERWISE THE REMAINDER OF THE DISCUSSION WATERS IS DOMINATED BY 
UPPER LEVEL RIDGING WHICH EXTENDS FROM A PARENT ANTICYCLONE OVER 
THE SW GULF OF MEXICO AND SE MEXICO NEAR 19N96W. UPPER LEVEL 
DIFFLUENCE UNDER THIS RIDGING IS HELPING TO SUPPORT CONVECTION 
ALONG THE MONSOON TROUGH AS IS DESCRIBED IN THE SECTION ABOVE.

SOUTHERLY FLOW S OF THE MONSOON TROUGH IS IN THE PROCESS OF  
INCREASING TO FRESH TO STRONG LEVELS S OF PANAMA AND W OF 
COLOMBIA WITH SEAS BUILDING TO UP TO 8 FT. BY FRI MORNING INTO 
EARLY AFTERNOON...THESE CONDITIONS ARE EXPECTED TO DIMINISH AND 
SUBSIDE.

$$
LEWITSKY