000
AXPZ20 KNHC 232150
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC WED SEP 23 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 1008 MB SURFACE LOW IS ANALYZED AT 10N91W AND A TROPICAL WAVE 
EXTENDS FROM 06-14N ALONG 97W AND HAS BEEN PROGRESSING W AT 
ABOUT 12 KT. SCATTERED MODERATE ISOLATED STRONG CONVECTION 
SURROUNDS THESE TWO FEATURES FROM 06-14N BETWEEN 86-103W.
   
A TROPICAL WAVE WAS ANALYZED FROM 03-13N ALONG 123W...AND HAS 
BEEN MOVING W AT 10-15 KT. CURRENTLY SCATTERED MODERATE ISOLATED 
STRONG CONVECTION IS OBSERVED WITHIN 180 NM EITHER SIDE OF WAVE 
AXIS.

A 1008 MB LOW PRES IS SPINNING NEAR 15N134W WITH ISOLATED 
MODERATE TO STRONG CONVECTION NOTED WITHIN 75 NM OVER THE NE 
SEMICIRCLE. THIS LOW SHOULD GRADUALLY WEAKEN TO AN OPEN TROUGH 
ON THU. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

THE MONSOON TROUGH AXIS EXTENDS SW FROM THE CARIBBEAN COAST OF  
COLOMBIA AT 11N74W TO ACROSS NORTHERN PANAMA TO THE PACIFIC 
COAST OF COSTA RICA AT 08N84W...THEN EXTENDS NW TO THE EMBEDDED 
LOW PRES AT 10N91W...THEN CONTINUES W THROUGH THE TROPICAL WAVE 
AT 10N97W TO 10N110W WHERE IT LOSES IDENTITY. EXCEPT AS 
PREVIOUSLY DESCRIBED IN ASSOCIATION WITH THE TWO TROPICAL LOWS 
AND TROPICAL WAVE...ISOLATED MODERATE TO STRONG CONVECTION IS 
OBSERVED WITHIN 90 NM OF 04N81W...WITHIN THE AREA BOUNDED FROM 
06-16N BETWEEN 106-118W AND WITHIN 30 NM EITHER SIDE OF A LINE 
FROM 05N127W TO 04N135W.

...DISCUSSION...

A WEAK SURFACE RIDGE EXTENDS FROM 32N135W TO 15N106W. LIGHT TO  
GENTLE ANTICYCLONIC FLOW IS OBSERVED ACROSS THE DISCUSSION AREA 
TO THE N OF 17N AND W OF 116W. THE PRESSURE GRADIENT E OF THE 
RIDGE IS SUPPORTING MODERATE NW FLOW ACROSS THE PACIFIC WATERS 
FROM 21-27N BETWEEN 108-115W TO INCLUDE THE GULF OF CALIFORNIA 
TO THE S OF 27N. EXPECT LITTLE CHANGE TILL THE GRADIENT RELAXES 
ON FRI WHEN MODERATE TO FRESH NE TRADES ARE EXPECTED TO DEVELOP 
S OF THE RIDGE ACROSS THE TROPICAL WATERS FROM 14-21N BETWEEN 
115-123W ON FRI. 

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.  
    
$$
NELSON