000
AXPZ20 KNHC 162102 RRA
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC FRI OCT 16 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 
2100 UTC.               

...SPECIAL FEATURES...

TROPICAL DEPRESSION NINETEEN-E IS CENTERED NEAR 9.5N 126.2W AT 
21 00 UTC MOVING WEST OR 265 DEGREES AT 13 KT. ESTIMATED MINIMUM 
CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 
KT WITH GUSTS TO 40 KT. SCATTERED MODERATE TO STRONG CONVECTION 
WAS NOTED WITHIN 120 NM SE AND 30 NM NW SEMICIRCLES. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WAS NOTED ELSEWHERE WITHIN 
60 NM OF LINE 15N125W TO 12N128W TO 08N128W. THE DEPRESSION IS 
FORECAST TO INTENSIFY TO A TROPICAL STORM TONIGHT AND CONTINUE 
TO GRADUALLY INTENSIFY AS IT MOVES WESTWARD...REACHING MINIMAL 
HURRICANE INTENSITY SUN. PLEASE SEE LATEST FORECAST ADVISORY 
UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS 
ON TROPICAL DEPRESSION NINETEEN-E. 

GULF OF TEHUANTEPEC...LATEST SCATTEROMETER DATA SUGGESTS WINDS 
OVER THE GULF OF TEHUANTEPEC HAVE DIMINISH TO 30 KT. WINDS ARE 
EXPECTED TO ONCE AGAIN INCREASE TO MINIMAL GALE FORCE LATE 
TONIGHT BEFORE ONCE AGAIN DIMINISHING BELOW GALE FORCE SUN. SEAS 
IN THE 10-14 FT RANGE WILL PREVAIL THROUGHOUT THE DURATION OF 
THIS EVENT. 

...TROPICAL WAVES...                                             

A TROPICAL WAVE AXIS WAS LOCATED NEAR 103W FROM 07N TO 15N. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS NOTED FROM 15N 
TO 18N BETWEEN 104W AND 108W.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
           
THE MONSOON TROUGH EXTENDS FROM 12N86W TO 09N95W TO 09N109W. THE 
ITCZ EXTENDS FROM 07N134W TO 08N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WAS NOTED OVER FORECAST WATERS N OF 
06N BETWEEN 85W AND 101W. 

...DISCUSSION... 

HIGH PRESSURE OF 1018 MB CENTERED NEAR 26N134W EXTENDS A RIDGE 
SE TO NEAR 20N113W. THE PRESSURE GRADIENT BETWEEN THE AREA OF 
HIGH PRESSURE AND TROPICAL DEPRESSION NINETEEN-E IS SUPPORTING 
AN AREA OF 20-30 KT WINDS OVER THE NORTHERN SEMICIRCLE OF THE 
DEPRESSION. A COLD FRONT HAS MOVED INTO THE FAR NW WATERS 
EXTENDING FROM 30N137W TO 28N140W. NW SWELLS IN ASSOCIATION WITH 
THIS FRONT WILL PROPAGATE INTO THE NW WATERS TONIGHT. THE COLD 
FRONT WILL SHIFT EASTWARD OVER THE NEXT 24 HOURS BEFORE 
DISSIPATING SUNDAY OVER THE NW WATERS. ASSOCIATED NW SWELL WILL 
CONTINUE TO PROPAGATE SE AND BY SUN AFTERNOON WILL COVER THE 
AREA W OF A LINE FROM 30N126W TO 20N132W.

CROSS-EQUATORIAL SW SWELL WITH SEAS IN THE 7-9 FT RANGE PREVAIL 
S OF 05N BETWEEN 99W AND 127W THROUGH SAT MORNING. THIS SWELL 
WILL SUBSIDE...WITH SEAS LESS THAN 8 FT EXPECTED BY SUN MORNING. 
DESPITE THE SUBSIDING SEAS...A NEW BATCH OF SW SWELL WITH 
PERIODS IN THE 19-21 SECOND RANGE...WILL REACH THE GALAPAGOS 
ISLANDS ON SAT MORNING AND THE PACIFIC COAST S OF CABO 
CORRIENTES MEXICO ON SUN MORNING. THIS LONG-PERIOD SWELL COULD 
MAKE FOR DANGEROUS CONDITIONS ENTERING AND EXITING PORTS AND 
WILL INCREASE THE THREAT OF RIP CURRENTS.

A DEVELOPING CENTRAL AMERICAN GYRE WILL HELP TO MAINTAIN GALE 
FORCE WINDS FOR MUCH OF THE FORECAST PERIOD OVER THE GULF OF 
TEHUANTEPEC. THIS GYRE WILL HELP INCREASE SW MONSOON FLOW OVER 
THE EASTERN WATERS WHICH WILL ADVECT ABUNDANT TROPICAL MOISTURE 
INTO THE EASTERN WATERS AND PORTIONS OF CENTRAL AMERICA AND 
SOUTHERN MEXICO. THIS WILL LEAD TO ACTIVE WEATHER OVER THIS AREA 
FOR THE NEXT SEVERAL DAYS. MODELS CONTINUE TO HINT THAT THE 
INTERACTION OF THE GALE FORCE WINDS WITH THE MONSOON TROUGH WILL 
HELP TO GENERATE A LOW PRESSURE AREA SOUTH OF THE GULF OF 
TEHUANTEPEC THIS WEEKEND. THIS LOW WILL HAVE THE POTENTIAL TO 
DEVELOP INTO A TROPICAL CYCLONE NEXT WEEK. REGARDLESS OF 
TROPICAL CYCLONE DEVELOPMENT...THIS AREA WILL BE ONE TO WATCH 
WITH INTEREST OVER THE NEXT SEVERAL DAYS AS THIS SYNOPTIC SETUP 
WILL BRING THE POTENTIAL FOR HEAVY RAINFALL WHICH MAY LEAD TO 
FLASH FLOODING AND DANGEROUS MUDSLIDES OVER PORTIONS OF CENTRAL 
AMERICA AND SOUTHERN MEXICO. 

$$ 
AL