000
AXPZ20 KNHC 170900
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON OCT 17 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0830 UTC.

...SPECIAL FEATURES...

THE LAST ADVISORY FOR TROPICAL DEPRESSION IRWIN WAS ISSUED BY 
THE NATIONAL HURRICANE CENTER AT 17/0000 UTC. THE REMNANT LOW 
PRESSURE OF IRWIN IS NEAR 14N108W AT THIS MOMENT. BROKEN TO 
OVERCAST MULTILAYERED CLOUDS AND POSSIBLE PRECIPITATION ARE
FROM 14N TO 16N BETWEEN 108W AND 115W. EXPECT 25 KT WIND SPEEDS
AROUND THE REMNANT LOW CENTER...WIND GUSTS RANGING FROM 30 TO
35 KT AND SEA HEIGHTS RANGING FROM 8 TO 11 FEET...WITHIN
15 TO 30 NM OF THE CENTER...DURING THE FORECAST PERIOD.
THE WIND SPEEDS AND SEA HEIGHTS WILL DECREASE GRADUALLY WITH 
TIME DURING THE FORECAST PERIOD.
 
...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH HAS BEEN DISRUPTED IN THE EASTERN PACIFIC 
OCEAN BETWEEN MEXICO AND CENTRAL AMERICA AND THE REMNANT LOW
OF IRWIN. THE MONSOON TROUGH EXTENDS FROM 17N106W...THROUGH THE
1009 MB REMNANT LOW PRESSURE CENTER OF IRWIN...TO 08N120W AND 
07N129W. THE ITCZ CONTINUES FROM 07N129W TO 07N133W BEYOND 
11N140W. SCATTERED STRONG RAINSHOWERS ARE FROM 13N TO 14N 
BETWEEN 91W AND 96W...AND IN ONE CELL THAT IS WITHIN A 15 NM 
RADIUS OF 15N97W. SCATTERED MODERATE RAINSHOWERS ARE WITHIN
FROM 05N TO 07N BETWEEN COLOMBIA AND 79W. RAINSHOWERS ARE 
POSSIBLE FROM 08N TO 13N BETWEEN 95W AND 103W...WITHIN 60 NM
ON EITHER SIDE OF 11N106W 10N115W 07N120W...FROM 04N TO 06N
BETWEEN 117W AND 124W...AND FROM 06N TO 09N BETWEEN 135W
AND 140W.

...DISCUSSION...

A MEAN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 32N135W. 
AN UPPER LEVEL TROUGH EXTENDS FROM THE CYCLONIC CENTER BEYOND 
24N140W. UPPER LEVEL CYCLONIC WIND FLOW COVERS THE AREA THAT IS 
TO THE WEST OF THE LINE THAT PASSES THROUGH 32N126W TO 22N132W 
BEYOND 15N140W. A 1010 MB LOW PRESSURE CENTER IS NEAR 30N137W. 
THIS LOW CENTER IS FORECAST TO MOVE NORTHEASTWARD DURING THE 
FIRST 24 HOURS OF THE FORECAST PERIOD...AND THEN DISSIPATE
BY 48 HOURS AT THE END OF THE FORECAST PERIOD. A SURFACE TROUGH 
EXTENDS FROM THE LOW CENTER TO 27N135W AND 22N139W. EXPECT
20 TO 25 KT WINDS MOVING AROUND THE LOW CENTER WITHIN 90 NM
OF THE CENTER AND WITHIN 180 NM TO THE EAST OF THE TROUGH.
SEA HEIGHTS WILL RANGE FROM 8 TO 13 FEET WITHIN 180 NM OF THE 
TROUGH. SEA HEIGHTS WILL REACH 9 FEET IN 24 HOURS AFTER THE
20 KT WINDS WEAKEN. THE SEA HEIGHTS WILL SUBSIDE SLOWLY TO
9 FEET AS THEY CONTINUE MOVING FURTHER SOUTHWARD TO THE
END OF THE FORECAST PERIOD.

AN EXTENSIVE AREA OF FRESH TO STRONG SOUTHWESTERLY MONSOONAL 
FLOW PERSISTS N OF 05N E OF 100W. SCATTEROMETER DATA CONFIRMED 
THE PRESENCE OF THESE WINDS WHICH ARE PUSHING ABUNDANT AMOUNTS 
OF TROPICAL MOISTURE INTO SECTIONS OF CENTRAL AMERICA AND 
SOUTHERN MEXICO. PERIODS OF HEAVY RAINFALL WILL OCCUR IN 
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 17/0300 UTC HIGH RESOLUTION ASCAT PASS INDICATED 20 TO 25 KT 
NORTHERLY WINDS IN AND DOWNSTREAM OF THE GULF OF TEHUANTEPEC 
AROUND A BROAD CYCLONIC CIRCULATION THAT CURRENTLY IS CENTERED 
NEAR 22N87W IN THE YUCATAN CHANNEL. FRESH TO STRONG WINDS ARE 
EXPECTED TO CONTINUE BLOWING IN THE GULF OF TEHUANTEPEC SINCE
THE BROAD SURFACE CYCLONIC WIND FLOW THAT IS EXPECTED PERSIST
DURING THE FORECAST PERIOD.

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

$$
MT