000
AXPZ20 KNHC 180914
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1005 UTC FRI OCT 18 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.

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

THE MONSOON TROUGH EXTENDS FROM 10N86W TO LOW PRES NEAR 10N92W 
TO 11N105W TO LOW PRES NEAR 9.5N111W TO 08N125W TO 11N131W. 
SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 120 NM S OF 
TROUGH BETWEEN 90W AND 100W. NUMEROUS MODERATE SCATTERED STRONG 
CONVECTION WAS NOTED WITHIN 90 NM N AND 120 NM S OF TROUGH 
BETWEEN 107W AND 111W. SCATTERED MODERATE CONVECTION WAS NOTED 
WITHIN 90 NM N AND 60 NM S OF TROUGH BETWEEN 111W AND 116W. 
 

...DISCUSSION...                                              

HIGH PRESSURE 1029 MB IS CENTERED WELL N OF THE AREA NEAR 
49N135W. THE DISTANCE OF THE HIGH PRESSURE CENTER FROM THE 
FORECAST AREA IS KEEPING THE PRESSURE GRADIENT OVER THE AREA 
WEAK. AS A RESULT...RELATIVELY BENIGN MARINE CONDITIONS PREVAIL 
OVER THE FORECAST REGION WITH WIDESPREAD GENTLE TO MODERATE 
WINDS AND 4-6 FT SEAS. 

POST-TROPICAL REMNANT LOW PRISCILLA HAS A WELL-DEFINED SWIRL OF 
LOW CLOUDS CENTERED NEAR 19N125W. THE LOW CONTINUES TO MOVE OVER 
COOL WATER AND IS EXPECTED TO CONTINUE WEAKENING...LIKELY 
BECOMING A TROUGH BY LATE TODAY. THE TROUGH WILL MOVE WESTWARD 
REACHING 130W BY SAT AFTERNOON AND 135W BY SUN AFTERNOON. LATEST 
SCATTEROMETER PASSES INDICATE WINDS OF 20 KT IN THE NW QUADRANT 
OF THE REMNANT LOW WITH SEAS TO 7 FT.  

LOOKING AHEAD...LONG PERIOD NW SWELL WILL IMPACT THE NW WATERS 
SUN AND MON. WAVE MODEL GUIDANCE SHOWS LEADING EDGE OF SWELL 
TRAIN WITH 22-23 SEC PERIOD...WHICH WILL PRODUCE UNUSUALLY LARGE 
SURF HEIGHTS AS IT REACHES SHALLOW WATER ALONG THE PACIFIC COAST 
NEXT WEEK. THIS POWERFUL SWELL EVENT WILL BE ASSOCIATED WITH A 
STRONG LOW PRES SYSTEM LOCATED W OF AREA.
 
$$ 
AL