000
AXPZ20 KNHC 170901
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1005 UTC THU OCT 17 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0830 UTC.

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

THE MONSOON TROUGH EXTENDS FROM 10N86W TO LOW PRES NEAR    
12N88W TO 10N108W TO 10N126W. THE ITCZ EXTENDS FROM 10N126W TO 
10N140W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 75 NM 
SW OF CENTRAL AMERICA BETWEEN 86W AND 91W. SCATTERED MODERATE 
CONVECTION IS WITHIN 120 NM SW OF THE MONSOON TROUGH BETWEEN  
84W AND 89W...FROM 08N TO 10N BETWEEN 122W AND 126W...AND ALSO 
WITHIN 180 NM S OF THE ITCZ BETWEEN 132W AND 136W.

...DISCUSSION...                                                 

ALOFT...A RIDGE/TROUGH PATTERN DOMINATES THE NORTHERN DISCUSSION 
WATERS...WITH THE RIDGE FROM 32N131W TO 20N137W...AND THE TROUGH 
REACHING FROM SOUTHERN CALIFORNIA THROUGH 32N119W TO 14N136W. 
DRY AND STABLE AIR PREVAILS E OF THE RIDGE AXIS TO THE TROUGH 
AXIS...AS WELL AS N OF 25N E OF 120W. 

A LARGE ANTICYCLONE CENTERED OVER THE S CENTRAL GULF OF MEXICO 
NEAR 24N88W EXTENDS  A RIDGE ACROSS SOUTH-CENTRAL MEXICO INTO 
THE PACIFIC WATERS TO NEAR 10N116W...INDUCING EASTERLY FLOW 
ALOFT ACROSS THE WATERS E OF 116W. AN INVERTED UPPER LEVEL 
TROUGH IS WEAKENING AND SHRINKING WHILE REACHING FROM 14N115W  
TO 10N120W.

AT THE SURFACE...POST-TROPICAL REMNANT LOW PRISCILLA IS NEAR 
19.5N121W AT 1010 MB. ASSOCIATED CONVECTION IS VERY LIMITED WITH 
MAINLY SCATTERED SHOWERS AND ISOLATED TSTMS ACROSS THE NW 
PORTION OF THE LOW. LINGERING FRESH TO STRONG WINDS AND 8-9 FT 
SEAS ARE WITHIN 180 NM IN THE NW AND N QUADRANTS OF PRISCILLA. 
THESE MARINE CONDITIONS ARE FORECAST TO DIMINISH AND SUBSIDE 
DURING THE NEXT 24 HOURS WITH THE REMNANT LOW DEGENERATING INTO 
TROUGH AROUND 48 HOURS. 

OUTSIDE OF PRISCILLA...RELATIVELY BENIGN MARINE CONDITIONS 
DOMINATE THE DISCUSSION WATERS WITH LIGHT TO MODERATE WINDS AND 
4-7 FT SEAS. A RIDGE IS NW OF PRISCILLA REACHING FROM 32N138W SE 
TO 25N114W. A WEAK 1010 MB LOW PRES AREA IS EMBEDDED IN THE 
MONSOON TROUGH NEAR 09.5N110W AS CAPTURED BY A RECENT ASCAT 
PASS. ASSOCIATED CONVECTION IS LIMITED. THIS LOW IS FORECAST TO 
MOVE W AROUND 5-10 KT THROUGH THE NEXT 48 HOURS. 

ANOTHER AREA OF LOW PRES IS WELL TO THE E...NEAR 12N88W. THIS 
LOW FORMED ALONG THE REMNANTS OF A TROPICAL WAVE WHICH HAS 
RECENTLY SHIFTED FROM CENTRAL AMERICA INTO THE FAR E PACIFIC 
WATERS. ASSOCIATED CONVECTION IS DESCRIBED IN THE SECTION ABOVE. 
THE LOW IS FORECAST TO REACH 10N96W BY LATE FRI NIGHT. MONSOONAL 
SOUTHERLY FLOW IS FORECAST TO INCREASE TO MODERATE TO FRESH AS 
IT MOVES W WHICH WILL BUILD SEAS TO 6-7 FT.
 
$$ 
LEWITSKY