000
AXPZ20 KNHC 222150
TWDEP 

ZCZC MIAWRKEP 151334
TTAA00 KMIA DDHHMM

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC TUE SEP 22 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 WAVES... 

.A TROPICAL WAVE IS ANALYZED FROM 05-16N BETWEEN 92-94W WITH 
SCATTERED MODERATE ISOLATED STRONG CONVECTION FLARING WITHIN
120 NM OF WAVE AXIS AND ALSO W OF THE WAVE WITHIN 150 NM OF 
12.5N99W. 

A TROPICAL WAVE WAS ANALYZED FROM 06N120W TO 16.5N114W AND
HAS BEEN MOVING W AT ABOUT 12 KT. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS NOTED WITHIN 210 NM EITHER SIDE
OF THE WAVE AXIS.

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

THE MONSOON TROUGH AXIS EXTENDS W FROM THE CARIBBEAN COAST OF  
COLOMBIA AT 10N75W TO ACROSS THE PANAMA AND COSTA RICA BORDER TO 
THE PACIFIC COAST OF COSTA RICA AT 09N84W...CONTINUES W TO THE 
TROPICAL WAVE AT 10N93W TO 09N101W...THEN TURNS SLIGHTLY NW TO 
12N114W WHERE IT LOSES IDENTITY. EXCEPT AS PREVIOUSLY DESCRIBED 
IN ASSOCIATION WITH THE TWO TROPICAL WAVES...SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS OBSERVED FROM 03-11N E OF 90W TO 
THE COAST OF COLOMBIA. SIMILAR CONVECTION IS NOTED WITHIN 90  NM 
OF 18N121W...AND DECAYING WITHIN 150 NM OF 11N138W.

...DISCUSSION...

A WEAK SURFACE RIDGE EXTENDS FROM 32N134W TO 15N105W WITH A WEAK 
TROUGH FILLING JUST N OF THE RIDGE AXIS NEAR 27N120W AND 
SURROUNDED BY LIGHT AND VARIABLE WINDS. LIGHT TO GENTLE 
ANTICYCLONIC FLOW IS OBSERVED ELSEWHERE ACROSS THE DISCUSSION 
AREA TO THE N OF 15N AND W OF 100W. THE TROUGH WILL GRADUALLY 
DISSIPATE THROUGH WED WITH THE RIDGE AXIS FORECAST FROM 32N128W 
TO 15N100W ON THU.
 
THE PRESSURE GRADIENT WELL E OF THE RIDGE...AND W OF TROUGHING 
OVER CENTRAL MEXICO IS SUPPORTING MODERATE NW FLOW ACROSS THE 
PACIFIC WATERS FROM 21-27N BETWEEN 105-115W...TO INCLUDE THE 
GULF OF CALIFORNIA TO THE S OF 27N. EXPECT LITTLE CHANGE TILL 
THE GRADIENT RELAXES ON FRI.  

MODERATE TO FRESH NE TRADES ARE OBSERVED WELL S OF THE RIDGE 
ACROSS THE TROPICAL WATERS FROM 13-18N W OF 130W WHERE THE 
CONVECTION IS CURRENTLY DECAYING AS PREVIOUSLY MENTIONED...BUT 
MAY REGENERATE AS CONDITIONS ARE FAVORABLE UNDER AN UPPER RIDGE.

GAP WINDS...THE PRESSURE GRADIENT BETWEEN WEAK RIDGING IN THE  
GULF OF MEXICO...AND THE TROPICAL WAVE PASSING W THROUGH THE 
PACIFIC WATERS TO THE S OF THE GULF OF TEHUANTEPEC...IS DRIVING 
STRONG NORTHERLY WINDS THROUGH CHIVELA PASS. LITTLE CHANGE 
EXPECTED THROUGH EARLY SUN MORNING WITH THE STRONGEST WINDS 
EXPECTED DURING MAXIMUM DRAINAGE AROUND SUNRISE EACH MORNING.  

NORTHERLY SWELL IS MIXING WITH CROSS EQUATORIAL SE AND SW SWELL 
ACROSS THE DEEP TROPICS GENERALLY S OF 07N BETWEEN 95-130W 
RESULTING IN COMBINED SEAS OF 7-9 FT. EXPECT THESE SEAS TO 
SUBSIDE THROUGH WED...THEN BUILD AGAIN IN RE-ENFORCING SOUTHERLY 
SWELL ON THU-FRI.
    
$$
NELSON