Tropical Weather Discussion
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000
AXPZ20 KNHC 180959
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU SEP 18 2014

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
0915 UTC.

...SPECIAL FEATURES...
HURRICANE POLO WAS LOCATED NEAR NEAR 16.7N 105.0W 988 MB AT 0900
UTC SEP 18...OR ABOUT 165 MILES...265 KM SSW OF MANZANILLO
MEXICO...MOVING WNW OR 300 DEG AT 7 KT. MAXIMUM SUSTAINED WINDS
65 KT GUSTS 80 KT. AT 18/0300 UTC. NUMEROUS STRONG CONVECTION
WAS OCCURRING WITHIN 45 NM N AND 60 NM S SEMICIRCLES...WHILE
SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS ELSEWHERE
WITHIN 150 NM NE...180 NM SE...270 NM SW AND 240 NM NW
QUADRANTS. POLO IS EXPECTED TO CONTINUE MOVING NW TODAY AND
PARALLEL TO THE SOUTHWESTERN COAST OF MEXICO...THEN GRADUALLY
BEND MORE W-NW OVER THE NEXT FEW DAYS. NORTHEASTERLY VERTICAL
WINDSHEAR HAS BEGUN TO IMPACT POLO...AND WILL LIMIT
STRENGTHENING OVER THE NEXT DAY OR SO. BEYOND THAT TIME...COOLER
WATERS AND INCREASING VERTICAL WIND SHEAR ARE EXPECTED TO CAUSE
A GRADUAL WEAKENING OF POLO. AS POLO PASSES BY THE MEXICAN
COASTLINE DURING THE NEXT 24 HOURS...OUTER BANDS OF SHOWERS AND
THUNDERSTORMS ARE LIKELY TO AFFECT THE COASTAL ZONES FROM
WESTERN GUERRERO TO JALISCO...WITH THE POTENTIAL FOR HEAVY RAINS
LEADING TO FLASH FLOODS AND MUDSLIDES IN AREAS PREVIOUSLY
AFFECTED BY NORBERT AND ODILE. SEE THE LATEST INTERMEDIATE
PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPEP2/WTPZ32 KNHC
AND FORECAST/ ADVISORY UNDER HEADERS MIATCMEP2/WTPZ22 KNHC FOR
MORE DETAILS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM 08N74W TO 09N88W TO 12N92W...
WHERE IT HAS FRACTURED...THEN RESUMES SW OF HURRICANE POLO NEAR
13N107W TO 11.5N122W...WHERE IT TRANSITIONS TO ITCZ...CONTINUING
ON TO 10N127W TO 13.5N140W. SCATTERED MODERATE TO STRONG WITHIN
180 NM EITHER SIDE OF TROUGH E OF 91W. SCATTERED MODERATE TO
STRONG FROM 07.5N TO 11.5N BETWEEN 98W AND 101W.

...DISCUSSION...
A WEAKENING COLD FRONT EXTENDS THROUGH 30N126W TO 23N140W. NW
SWELL BEHIND THE FRONT IS MAINTAINING SEAS TO 8-10 FT. THE FRONT
WILL CONTINUE TO WEAKEN THROUGH TONIGHT WITH SEAS
GRADUALLY SUBSIDING BELOW 8 FT.

A WEAK SURFACE RIDGE OVER THE NW AND NORTH-CENTRAL WATERS W OF
120W CONTINUES TO MAINTAIN GENTLE TO MODERATE TRADE WINDS N OF
THE ITCZ. THE RIDGE WILL WEAKEN FURTHER DURING THE NEXT 24 HOURS
AS THE FRONTAL TROUGH ABUTS IT THEN DISSIPATED...WITH A NEW
HIGH AND RIDGE BUILDING MODESTLY INTO THE AREA FROM THE NW FRI
THROUGH SAT.

LONG PERIOD SW SOUTHERN HEMI SWELL AFFECTING THE WATERS E OF
110W THE PAST FEW DAYS HAS SUBSIDED AND WILL SLOWLY FADE THROUGH
FRI...WITH A NEW AND SMALLER PULSE OF SW SWELL ACROSS THE
EQUATOR OVER THE WEEKEND.

$$
STRIPLING


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