000
AXPZ20 KNHC 170238
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC SAT OCT 17 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0230 UTC.               

...SPECIAL FEATURES...

RECENTLY UPGRADED TROPICAL STORM OLAF IS CENTERED NEAR 9.7N 
127.6W AT 0300 UTC MOVING WEST OR 270 DEGREES AT 12 KT. 
ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB. MAXIMUM SUSTAINED 
WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. SCATTERED MODERATE TO 
STRONG WITHIN 90 NM OF CENTER. SCATTERED MODERATE ISOLATED 
STRONG ELSEWHERE FROM 06N TO 14N BETWEEN 125W AND 132W. OLAF IS 
FORECAST TO INTENSIFY TO CONTINUE TO INTENSIFY AS THE SYSTEM 
MOVES WESTWARD...REACHING MINIMAL HURRICANE INTENSITY SUN. 
PLEASE SEE LATEST FORECAST ADVISORY UNDER AWIPS/WMO HEADERS 
MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS ON OLAF. 

GULF OF TEHUANTEPEC...WINDS OF MINIMAL GALE FORCE ARE FUNNELING 
INTO THE GULF OF TEHUANTEPEC. WINDS WILL REMAIN AT NEAR GALE 
FORCE OR MINIMAL GALE FORCE OVER THE NEXT COUPLE OF DAYS. SEAS 
IN THE 10-14 FT RANGE WILL PREVAIL THROUGHOUT THE DURATION OF 
THIS EVENT. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
           
THE MONSOON TROUGH EXTENDS FROM 13N88W TO 09N98W TO 09N102W TO 
08N111W. ITCZ FROM 07N137W TO 08N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WAS NOTED OVER FORECAST WATERS N OF 
06N BETWEEN 83W AND 101W. 

...DISCUSSION... 

HIGH PRESSURE OF 1017 MB CENTERED NEAR 26N136W EXTENDS A RIDGE 
SE TO NEAR 22N116W. A COLD FRONT HAS MOVED INTO THE FAR NW 
WATERS EXTENDING FROM 30N137W TO 28N140W. NW SWELLS IN 
ASSOCIATION WITH THIS FRONT HAVE MOVED INTO THE AREA WITH SEAS 
TO 8 FT NW OF A LINE FROM 30N136W TO 27N140W. 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 30N124W TO 20N131W.

CROSS-EQUATORIAL SW SWELL WITH SEAS IN THE 7-9 FT RANGE PREVAIL 
S OF 05N BETWEEN 100W AND 127W. 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 WINDS 
OF NEAR GALE TO MINIMUM GALE FORCE FOR 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 
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