000
AXPZ20 KNHC 161529
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN OCT 16 2011

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...SPECIAL FEATURES...

THE CENTER OF TROPICAL DEPRESSION IRWIN AT 16/1500 UTC IS NEAR 
14.1N 107.8W. IRWIN IS MOVING SOUTH-SOUTHWESTWARD OR 230 DEGREES 
4 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. THE 
MAXIMUM SUSTAINED WIND SPEEDS ARE 30 KT WITH GUSTS TO 40 KT. 
SCATTERED STRONG RAINSHOWERS ARE WITHIN 90 NM IN THE SW 
QUADRANT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. 
 
...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTEND FROM 12N110W TO 08N128W TO 11N140W. 
SCATTERED STRONG RAINSHOWERS ARE FROM 13N TO 14N BETWEEN 90W AND 
96W. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 60 NM S OF 
AXIS BETWEEN 115W AND 118W. 

...DISCUSSION...

A 1007 MB LOW PRESSURE CENTER IS NEAR 31N137W. THIS LOW CENTER 
IS FORECAST TO MOVE SLOWLY EAST SOUTHEASTWARD BUT REMAIN NEAR OR 
JUST N OF 30N. A STATIONARY FRONT EXTENDS FROM 30N131W TO 
20N140W. FRESH 20 KT WINDS AND SEAS TO 15 FT ARE FOUND W OF THE 
FRONT. THE FRONT WILL DISSIPATE WITHIN THE NEXT 24 HOURS...WITH 
WINDS DIMINISHING BELOW 20 KT. SEAS WILL SLOWLY SUBSIDE TO NEAR 
9 FT AS THEY CONTINUE MOVING FURTHER SOUTHWARD THROUGH THE 
FORECAST PERIOD. 

AN EXTENSIVE AREA OF FRESH TO STRONG SOUTHWESTERLY MONSOONAL FLOW
CONTINUES N OF 05N E OF 100W. THESE WINDS ARE ADVECTING ABUNDANT 
TROPICAL MOISTURE OVER PORTIONS OF CENTRAL AMERICA AND SOUTHERN 
MEXICO. THIS WILL BRING PERIODS OF HEAVY RAINFALL INTO SECTIONS 
OF THE PACIFIC COASTS OF SOUTHEASTERN MEXICO... GUATEMALA...EL 
SALVADOR...SOUTHERN HONDURAS AND NICARAGUA. THE PERIODS OF HEAVY 
MONSOONAL RAINFALL HAVE THE POTENTIAL TO CREATE LIFE-THREATENING 
FLASH FLOODS AND MUD SLIDES IN SOME AREAS.

A BROAD CYCLONIC CIRCULATION CENTERED OVER THE YUCATAN PENINSULA 
IS REMINISCENT OF A MONSOON DEPRESSION. NORTHERLY FLOW OVER THE 
SW GULF OF MEXICO ASSOCIATED WITH THIS CIRCULATION CONTINUES TO 
FUNNEL FRESH TO STRONG WINDS THROUGH THE CHIVELA PASS INTO THE 
GULF OF TEHUANTEPEC. AS A NOTE OF INTEREST TO INDICATE THE 
INFLUENCE OF THIS CYCLONIC CIRCULATION OVER THE AREA...THE WINDS 
FUNNELING INTO THE GULF OF TEHUANTEPEC ARE TURNING NW THEN WEST 
AS IT MOVES FURTHER FROM THE GULF OF TEHUANTEPEC. 
TYPICALLY...THE WINDS FUNNELING INTO THE GULF OF TEHUANTEPEC 
TURN NE THEN E AS IT MOVES FURTHER FROM THE GULF OF TEHUANTEPEC. 
WITH THIS CYCLONIC CIRCULATION EXPECTED TO CONTINUE THROUGH THE 
FORECAST PERIOD...FRESH TO STRONG WINDS ARE EXPECTED TO CONTINUE 
OVER THE GULF OF TEHUANTEPEC. 

THE REMAINDER OF THE REGIONAL WATERS S OF 20N E OF 130W ARE 
DOMINATED BY MERGING NORTHERLY AND SOUTHWESTERLY SWELL. THIS 
SWELL EVENT WILL CONTINUE TO SUBSIDE FROM THE NORTHWEST TO THE 
SOUTHEAST DURING THE NEXT 48 HOURS.

$$
AL