000
AXPZ20 KNHC 190923
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1005 UTC SAT OCT 19 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 
0900 UTC.

...SPECIAL FEATURES... 

A BROAD AREA OF LOW PRESSURE EMBEDDED WITHIN THE MONSOON TROUGH 
IS LOCATED NEAR 11.5N98W. SHOWERS AND THUNDERSTORMS CONTINUE TO 
SHOW SIGNS OF ORGANIZATION IN ASSOCIATION WITH THIS SYSTEM. 
SATELLITE IMAGERY SHOWS NUMEROUS MODERATE TO SCATTERED STRONG 
CONVECTION WITHIN 210 NM N SEMICIRCLE AND SCATTERED MODERATE 
ISOLATED STRONG WITHIN 180 NM SW AND 90 NM SE QUADRANTS OF THE 
LOW CENTER. CONDITIONS ARE CONDUCIVE FOR GRADUAL DEVELOPMENT OF 
THIS SYSTEM DURING THE NEXT SEVERAL DAYS. THE LATEST NHC 
TROPICAL WEATHER OUTLOOK GIVES THIS LOW PRES AREA A MEDIUM 
CHANCE OF DEVELOPING INTO A TROPICAL CYCLONE DURING THE NEXT 48 
HOURS.  

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

THE MONSOON TROUGH EXTENDS FROM 13N87W TO 14N91W TO 1009 MB LOW 
PRES NEAR 11.5N98W TO 12.5N107W TO 1011 MB LOW PRES NEAR 09N115W 
TO 06N126W WHERE LOW LEVEL WINDS SUGGEST A TRANSITION TO ITCZ 
WHICH EXTENDS TO BEYOND 11N140W. NUMEROUS MODERATE SCATTERED 
STRONG CONVECTION WAS NOTED WITHIN 120 NM S OF TROUGH BETWEEN 
89W AND 92W. NUMEROUS MODERATE SCATTERED STRONG CONVECTION WAS 
NOTED WITHIN 120 NM N OF TROUGH BETWEEN 97W AND 100W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WAS NOTED WITHIN 180 NM S OF 
TROUGH BETWEEN 100W AND 111W. SCATTERED MODERATE CONVECTION WAS 
NOTED WITHIN 210 NM N OF TROUGH BETWEEN 113W AND 117W. SCATTERED 
MODERATE CONVECTION WAS NOTED WITHIN 120 NM N AND 60 NM S OF 
TROUGH BETWEEN 118W AND 122W. 

...DISCUSSION...                                              

HIGH PRESSURE OF 1028 MB IS CENTERED WELL N OF AREA NEAR 
47N135W. THE DISTANCE OF THE HIGH PRESSURE CENTER FROM THE AREA 
IS KEEPING A WEAK PRES GRADIENT OVER THE AREA. AS A 
RESULT...RELATIVELY BENIGN MARINE CONDITIONS PREVAIL OVER MOST 
OF THE DISCUSSION AREA...WITH WIDESPREAD GENTLE TO MODERATE 
WINDS AND SEAS IN THE 4-6 FT RANGE.

A SURFACE TROUGH...THE REMNANT LOW OF PRISCILLA...IS NOTED ALONG 
128N FROM 15N TO 20N. A LOCALLY TIGHTER PRESSURE GRADIENT N OF 
THE TROUGH IS MAINTAINING MODERATE TO FRESH WINDS OVER THE 
NORTHERN PART OF THE TROUGH. THE TROUGH WILL CONTINUE TO MOVE 
WESTWARD...REACHING 130W BY THIS AFTERNOON AND 135W BY SUN 
AFTERNOON. 

ANOTHER AREA OF LOW PRESSURE EMBEDDED WITHIN THE MONSOON TROUGH 
IS CENTERED NEAR 09N115W. SCATTEROMETER DATA SHOWED AN ELONGATED 
CYCLONIC CIRCULATION WITH 15-20 KT SW MONSOONAL WINDS SOUTH OF 
THE CIRCULATION CENTER. THE LOW WILL DRIFT W THROUGH SUN WITH 
LITTLE CHANGE IN INTENSITY. 

LOOKING AHEAD...LONG PERIOD NW SWELL ASSOCIATED WITH STRONG LOW 
PRES SYSTEM LOCATED NW OF AREA WILL PROPAGATE INTO THE NW WATERS 
SUN AND SPREAD SOUTHEASTWARD MON THROUGH WED. WAVE MODEL 
GUIDANCE SHOWS THE LEADING EDGE OF SWELL TRAIN WITH 22-23 SEC 
PERIOD... WHICH WILL PRODUCE LARGE SURF CONDITIONS AS IT REACHES 
SHALLOW WATER ALONG THE PACIFIC COAST NEXT WEEK.
 
$$ 
AL