000
AXPZ20 KNHC 242156
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC WED SEP 24 2014

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.

...SPECIAL FEATURES...
THE LOW PRESSURE CENTER BEING MONITORED OFFSHORE OF MEXICO THE 
PAST FEW DAYS WAS UPGRADED TO TROPICAL DEPRESSION EIGHTEEN-E  
THIS MORNING AT 1500 UTC. AT 24/2100 UTC...IT IS CENTERED NEAR 
15.1N 106.8W OR ABOUT 275 NM...510 KM SSW OF MANZANILLO MEXICO 
MOVING WESTWARD OVER THE OPEN WATERS OF THE EASTERN PACIFIC AT 
12 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM 
SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. NUMEROUS 
MODERATE TO STRONG CONVECTION IS NOTED WITHIN 180 NM SW QUADRANT 
OF LOW CENTER DUE TO STRONG UPPER-LEVEL NORTHEASTERLY WINDS. 
THIS SHEARED ENVIRONMENT IS EXPECTED TO PREVENT SIGNIFICANT 
STRENGTHENING DURING THE NEXT 12-14 HOURS. SEE LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 FOR 
MORE DETAILS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...        
MONSOON TROUGH EXTENDS FROM 07N78W TO LOW PRES NEAR 08N87W 1008 
MB TO 13N100W THEN CONTINUES SW OF T.D. EIGHTEEN-E FROM 11N108W 
TO 08N120W...WHERE IT TRANSITIONS TO ITCZ...CONTINUING ON TO 
05N130W TO BEYOND 06N140W. SCATTERED MODERATE CONVECTION IS 
NOTED FROM 07N TO 10N BETWEEN 85W AND 90W...AND FROM 09N TO 11N 
BETWEEN 92W AND 100W. SIMILAR CONVECTION IS ALSO NEAR 14N96W... 
AND WITHIN 90 NM N OF THE ITCZ AXIS BETWEEN 131W AND 137W.

...DISCUSSION...                                             
WEAK 1017 MB HIGH PRESSURE IS CENTERED OVER THE NW CORNER OF THE 
AREA NEAR 26N133W. THIS SYSTEM IS FORECAST TO DISSIPATE IN ABOUT 
6-12 HOURS AS A COLD FRONT MOVES ACROSS THE AREA. THE FRONT 
CURRENTLY EXTENDS FROM 30N132W TO 26N140W WITH MODERATE TO 
LOCALLY FRESH N TO NE WINDS BEHIND IT. LARGE NW SWELL GENERATED 
FROM THE LARGE AND POWERFUL STORM SYSTEM ACROSS THE NE PACIFIC 
HAS JUST BEGUN TO RAISE SEAS TO 9 FT BEHIND THIS COLD FRONT... 
AND WILL PROPAGATE SE THROUGHOUT THE NEXT FEW DAYS. THE FRONT IS 
EXPECTED TO MOVE SE ACROSS THE FORECAST WATERS...REACHING A 
POSITION FROM 30N125W TO 26N130W TO 23.5N140W THU AFTERNOON... 
THEN WILL GRADUALLY DISSIPATE BY FRI. BUILDING HIGH PRESSURE IN 
THE WAKE OF THE FRONT WILL INCREASE THE NORTHERLY FLOW TO 15-20 
KT ALONG THE PACIFIC COAST OF THE BAJA PENINSULA TO THE N OF 30N 
LATE THU...WITH THESE CONDITIONS SPREADING AS FAR S AS 27N ON 
FRI AFTERNOON...WITH THE GRADIENT BEGINNING TO RELAX FRI NIGHT. 
SEAS WILL BUILD TO 8-10 FT IN MIXING LONG PERIOD NW SWELL ACROSS 
THE DISCUSSION WATERS NW OF A LINE 30N116W TO 23N116W TO 18N130W 
TO 14N140W BY FRI AFTERNOON...THEN GRADUALLY SUBSIDE OVER THE 
WEEKEND.  

THE REMNANTS OF FORMER TROPICAL CYCLONE POLO ARE ANALYZED AS A 
1010 MB LOW PRESSURE NEAR 19N117W. WINDS REMAIN 15-20 KT WITHIN 
ABOUT 180 NM W OF THE CENTER...WITH SEAS OF 5-7 FT. THE LOW IS 
FORECAST TO MOVE SW TO A POSITION NEAR 17N118W IN 24 HOURS. 

VISIBLE SATELLITE IMAGERY SHOWS A WELL DEFINED SWIRL OF LOW 
CLOUDS NEAR 15N137.5W AND A 1014 MB LOW PRES WAS ANALYZED ON THE 
1800 UTC SURFACE MAP. THE LOW IS FORECAST TO DISSIPATE IN ABOUT 
24 HOURS AND THE ASSOCIATED TROUGH WILL CONTINUE TO MOVE 
WESTWARD.
 
$$
GR