000
AXPZ20 KNHC 242148
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC THU SEP 24 2015

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 
2145 UTC.               

...TROPICAL LOW AND TROPICAL WAVES... 

A 1007 MB SURFACE LOW IS EMBEDDED IN THE MONSOON TROUGH AT 
12N92W AND IS MOVING N-NW AT 05 KT. CURRENTLY SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS NOTED WITHIN 180 NM OVER THE E 
SEMICIRCLE OF THE LOW. THIS LOW IS EXPECTED TO CONTINUE 
NORTHWESTWARD WITH CONDITIONS BECOMING FAVORABLE FOR TROPICAL 
CYCLONE FORMATION IN ABOUT 3 DAYS.

A BROAD TROPICAL WAVE IS ANALYZED FROM 06-15N BETWEEN 98-102W   
...AND HAS BEEN MOVING W AT 10 KT. SCATTERED MODERATE ISOLATED
STRONG CONVECTION IS OBSERVED S OF 08N WITHIN 180 NM OF WAVE 
AXIS.

A TROPICAL WAVE WAS ANALYZED FROM 03N131W TO 20N123W WITH    
SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED S OF 10N 
WITHIN 180 NM W OF WAVE AXIS. SCATTERED MODERATE CONVECTION IS 
NOTED TO THE N OF 10N WITHIN 90 NM OF THE WAVE AXIS.  
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

THE MONSOON TROUGH AXIS EXTENDS W FROM THE CARIBBEAN COAST OF  
COLOMBIA AT 11N76W THEN DISSECTS COSTA RICA FROM E TO W REACHING 
THE PACIFIC COAST OF COSTA RICA AT 11N86W...THEN EXTENDS NW TO 
THE EMBEDDED LOW PRES AT 12N92W...THEN DIPS SW TO 11N95W AND 
CONTINUES W THROUGH THE TROPICAL WAVE ALONG 100W TO 10N120W 
WHERE IT LOSES IDENTITY. AN ITCZ FORMS NEAR 08N131W AND EXTENDS 
SW TO BEYOND 05N140W. EXCEPT AS PREVIOUSLY DESCRIBED IN 
ASSOCIATION WITH TROPICAL LOW AND TROPICAL WAVES...SCATTERED 
MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 30 NM 
EITHER SIDE OF A LINE FROM 04N77W TO 07N87W AND WITHIN 270 NM 
EITHER SIDE OF A LINE FROM 12N87W TO 06N113W TO 07N132W. 

...DISCUSSION...

A SURFACE RIDGE EXTENDS FROM 32N128W TO 12N120W. THE PRESSURE 
GRADIENT E OF THE RIDGE WILL TIGHTEN LATE SAT INCREASING THE 
NORTHERLY FLOW TO 15-20 KT ACROSS THE DISCUSSION AREA TO THE N 
OF 29N BETWEEN 120-127W...WITH SEAS BUILDING TO 7 FT. THE 
GRADIENT WILL RELAX SOME ON SUN. A WEAK COLD FRONT WILL ENTER 
THE FAR NW PORTION OF THE DISCUSSION AREA NEAR 30N140W ON FRI... 
AND CONTINUE SE REACHING A POSITION FROM 32N135W TO 26N136W LATE 
SAT NIGHT. BY THEN BUILDING HIGH PRESSURE NW OF THE FRONT WILL 
INCREASE THE POST-FRONTAL NW FLOW TO 20-25 KT WITH COMBINED SEAS 
BUILDING TO 11 FT NEAR 32N140W.
  
GAP WINDS...PULSES OF STRONG N-NE WINDS ARE EXPECTED ACROSS AND 
DOWNSTREAM OF THE GULF OF TEHUANTEPEC THROUGH THE WEEKEND WITH 
THE STRONGEST WINDS EXPECTED DURING MAXIMUM DRAINAGE AROUND 
SUNRISE EACH MORNING WITH SEAS SEAS BUILDING TO A MAX OF 11 FT
NEAR 14.5N96W.  
    
$$
NELSON