000
AXPZ20 KNHC 192141
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
2205 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2045 UTC.

...SPECIAL FEATURES... 
                                         
AN AREA OF LOW PRESSURE EMBEDDED WITHIN THE MONSOON TROUGH IS 
LOCATED NEAR 13N100W OR A FEW HUNDRED MILES SOUTH OF ACAPULCO 
MEXICO. SHOWER AND THUNDERSTORM ACTIVITY HAS BECOME BETTER 
ORGANIZED TODAY WITH SOME BANDING-LIKE FEATURES AND INCREASING 
DEEP CONVECTION NEAR THE LOW CENTER. ENVIRONMENTAL CONDITIONS 
ARE EXPECTED TO REMAIN CONDUCIVE FOR ADDITIONAL DEVELOPMENT... 
AND A TROPICAL DEPRESSION COULD FORM TONIGHT OR ON SUNDAY WHILE 
THIS LOW MOVES NORTHWESTWARD AT 5 TO 10 KT. THE LATEST NHC 
TROPICAL WEATHER OUTLOOK GIVES THIS LOW PRES AREA A HIGH CHANCE 
OF DEVELOPING INTO A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.  
INTERESTS ALONG THE SOUTH-CENTRAL COAST OF MEXICO SHOULD MONITOR 
THE PROGRESS OF THIS DISTURBANCE. REGARDLESS OF DEVELOPMENT... 
LOCALLY HEAVY RAINFALL...WHICH COULD CAUSE FLASH FLOODING AND 
MUD SLIDES...IS POSSIBLE OVER SOUTH-CENTRAL MEXICO DURING THE 
NEXT SEVERAL DAYS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
           
THE MONSOON TROUGH EXTENDS FROM 11N86W TO 1008 MB LOW PRES NEAR 
13N100W TO 1010 MB LOW PRES NEAR 10N114W TO 07N125W. THE ITCZ 
CONTINUES FROM 07N125W TO 08N133W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION IS FROM 08N TO 11N BETWEEN 86W AND 90W...FROM 
12N TO 15N BETWEEN 96W AND 102W AND FROM 10N TO 14N BETWEEN 102W 
AND 108W.

...DISCUSSION...
                                              
A 1028 MB HIGH PRESSURE LOCATED WELL N OF AREA NEAR 47N137W 
EXTENDS A RIDGE SE ACROSS THE NORTH WATERS TO NEAR 21N116W. THE 
DISTANCE OF THE HIGH PRESSURE CENTER FROM THE AREA IS KEEPING A 
WEAK PRES GRADIENT OVER THE FORECAST REGION. 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. THE EXCEPTION WILL BE SE OF THE LOW 
PRES LOCATED NEAR 13N100W WHERE SW WINDS ARE INCREASING TO NEAR 
30 KT WITH BUILDING SEAS TO AROUND 9 FT.

ANOTHER AREA OF LOW PRESSURE EMBEDDED WITHIN THE MONSOON TROUGH 
IS CENTERED NEAR 10N114W. 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. 

VISIBLE SATELLITE IMAGERY REVEALS A WELL DEFINED SWIRL OF LOW 
CLOUDS ASSOCIATED WITH THE REMNANTS OF PRISCILLA. A 1012 MB LOW 
PRES IS ANALYZED ON THE 1800 UTC SURFACE MAP NEAR 17N130.5W. 
SCATTEROMETER DATA SHOW WINDS OF 15-20 KT WITHIN ABOUT 90 NM 
NORTHERN SEMICIRCLE OF CENTER WITH SEAS TO 7 FT BASED ON AN 
ALTIMETER PASS. THIS SYSTEM WILL CONTINUE TO MOVE WWD WHILE 
WEAKENING INTO A TROUGH...REACHING 135W BY SUN AFTERNOON.

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.
 
$$ 
GR