000
AXPZ20 KNHC 032117
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU OCT 03 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.

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

THE MONSOON TROUGH FROM 10N85W TO 12N105W TO 1009 MB LOW PRES 
NEAR 12N109W TO 11N122W WHERE LOW LEVEL WINDS SUGGEST A 
TRANSITION TO ITCZ FROM 11N112W TO 10N140W. SCATTERED MODERATE 
CONVECTION WAS NOTED WITHIN 120 NM S OF TROUGH BETWEEN 86W AND 
93W. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 210 NM S OF 
TROUGH BETWEEN 93W AND 108W. SCATTERED MODERATE CONVECTION WAS 
NOTED WITHIN 210 NM N OF TROUGH BETWEEN 108W AND 115W. 

...DISCUSSION...

HIGH PRESSURE 1030 MB IS CENTERED N OF THE AREA NEAR 37N138W 
WITH ASSOCIATED RIDGE EXTENDING SE TO NEAR 20N111W. THE HIGH 
PRESSURE REMAINS FAR ENOUGH N OF THE FORECAST AREA WHERE THE 
PRESSURE GRADIENT IS PRODUCING WINDS BELOW ADVISORY CRITERIA. NW 
SWELLS CONTINUE TO PROPAGATE ACROSS THE FORECAST AREA WITH SEAS 
8 FT OR GREATER COVERING MUCH OF THE AREA N OF 10N AND W OF 110W.

THE PRESSURE GRADIENT BETWEEN THE HIGH PRESSURE CENTER MENTIONED 
ABOVE AND TROUGHING OVER THE WEST COAST OF THE UNITED STATES IS 
MAINTAINING GALE FORCE WINDS N OF THE AREA. NORTHERLY SWELLS 
GENERATED FROM THESE WINDS WILL CONTINUE TO PROPAGATE INTO THE 
NORTHERN PART OF THE FORECAST AREA OVER THE NEXT 24-36 HOURS. 
OVER THE NEXT COUPLE OF DAYS...THE AREA OF HIGH PRESSURE WILL 
WEAKEN AND MOVE NE WHILE THE TROUGH OVER THE WEST COAST WEAKENS. 
THIS WILL DECREASE WINDS N OF THE AREA ALLOWING FOR THE 
ASSOCIATED SWELLS TO DECREASE. BY SAT AFTERNOON SEAS OVER THE 
FORECAST AREA ASSOCIATED WITH THE SWELLS ARE EXPECTED TO SUBSIDE 
BELOW 8 FT. AS THE TROUGH WEAKENS...HIGH PRESSURE WILL BUILD 
OVER THE WESTERN UNITED STATES. THIS WILL RESULT IN NORTHERLY 
WINDS INCREASING TO 25 KT OVER THE FAR N PART OF THE GULF OF 
CALIFORNIA BY FRI AFTERNOON.

THE 1009 MB LOW NEAR 12N109W EMBEDDED WITHIN THE MONSOON TROUGH 
IS MOVING SLOWLY WESTWARD. THERE IS MINIMAL CONVECTION 
ASSOCIATED WITH THIS LOW. THIS LOW IS EXPECTED TO CONTINUE TO 
MOVE WESTWARD MOTION OVER THE NEXT 48 HOURS WITH NO SIGNIFICANT 
STRENGTHENING EXPECTED. 

$$
AL