000
AXNT20 KNHC 151804
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT MON SEP 15 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1745 UTC.

...SPECIAL FEATURES...
NONE.

...TROPICAL WAVES...
AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 31W/32W SOUTH OF 13N
MOVING WEST 10 TO 15 KT. ISOLATED MODERATE SHOWERS FROM 14N TO
17N BETWEEN 30W AND 33W.

AN ATLANTIC TROPICAL WAVE IS ALONG 54W/55W SOUTH OF 20N MOVING
WEST 10 TO 15 KT. A 1013 MB LOW PRESSURE CENTER IS ALONG THE 
WAVE NEAR 18N. STRONG SHOWERS AND THUNDERSTORMS FROM 15N TO 
16.5N BETWEEN 50W AND 53W. CONVECTIVE DEBRIS CLOUDS COVER THE 
ATLANTIC OCEAN FROM 14N TO 23N BETWEEN 41W AND 55W.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 72W/73W SOUTH OF 20N 
MOVING WEST 10 TO 15 KT. NO DEEP CONVECTIVE PRECIPITATION 
ACCOMPANIES THIS WAVE. ISOLATED MODERATE SHOWERS AND POSSIBLE 
THUNDERSTORMS IN THE CARIBBEAN SEA FROM 14N TO 17N BETWEEN 67W 
AND 73W MAY BE MORE RELATED MORE CORRECTLY TO A MIDDLE TO UPPER 
LEVEL TROUGH THAT EXTENDS FROM THE ATLANTIC OCEAN INTO THE EAST 
CENTRAL CARIBBEAN SEA NEAR 14N65W.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 85W/86W SOUTH OF 19N 
MOVING WEST 10 TO 15 KT. NUMEROUS STRONG SHOWERS AND 
THUNDERSTORMS ARE FROM PANAMA AND COSTA RICA TO 17N BETWEEN
81W AND 85W...IN SURFACE EASTERLY WINDS AND UPPER LEVEL
ANTICYCLONIC OUTFLOW UNDER AN UPPER LEVEL RIDGE. SCATTERED 
MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE WITHIN 60 
NM TO 90 NM ON EITHER SIDE OF THE LINE FROM 32N48W TO 29N55W TO 
26N58W TO TO 22N60W...IN BETWEEN THE 32N58W 24N61W TROUGH AND 
THE 26N46W CYCLONIC CENTER.

...THE ITCZ...
9N13W 7N32W 8N52W 9N62W IN NORTHEASTERN VENEZUELA.
ISOLATED MODERATE SHOWERS WITHIN 120 NM TO 180 NM ON EITHER SIDE 
OF 10N14W 7N32W 6N48W. SCATTERED MODERATE SHOWERS TO ISOLATED 
STRONG FROM 8N TO 10N BETWEEN 46W AND 52W. IT IS POSSIBLE THAT 
THIS PRECIPITATION IS NEAR THE BASE OF AN ATLANTIC OCEAN TROUGH.

...DISCUSSION...

THE GULF OF MEXICO...
A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM THE COASTAL WATERS 
OF SOUTHWESTERN MISSISSIPPI/THE WESTERN FLORIDA PANHANDLE TO THE 
CENTRAL/NORTH CENTRAL GULF OF MEXICO...INTO THE SOUTHWESTERN 
CORNER OF THE AREA. THIS TROUGH IS PROVIDING THE ENERGY FOR
A COLD FRONT THAT PASSES THROUGH SOUTHWESTERN MISSISSIPPI TO
THE NORTH CENTRAL GULF WATERS TO THE MEXICO GULF COAST ABOUT
120 NM SOUTH OF THE TEXAS BORDER. THE COLD FRONT CONTINUES
ACROSS INTERIOR MEXICO TO 24N100W AND CURVING NORTHWESTWARD
TO 30N109W. SCATTERED MODERATE SHOWERS WITHIN A 60 NM RADIUS
OF 26.5N96W. IT IS POSSIBLE THAT SHOWERS REMAIN WITHIN 120 NM 
OFF THE LOUISIANA COAST. ISOLATED MODERATE SHOWERS ARE ELSEWHERE
FROM THE WESTERN FLORIDA PANHANDLE TO 27N86W...AND FROM 22N TO 
24N BETWEEN 87W AND 92W.

FROM THE WESTERN ATLANTIC OCEAN INTO THE CARIBBEAN SEA...
A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM AN ATLANTIC CYCLONIC 
CIRCULATION CENTER NEAR 32N58W TO 24N61W 14N65W. ISOLATED 
MODERATE SHOWERS ARE NORTH OF 13N BETWEEN 60W AND 74W IN THE 
CARIBBEAN SEA. A SEPARATE MIDDLE TO UPPER LEVEL TROUGH EXTENDS 
FROM AN ATLANTIC OCEAN 22N57W CYCLONIC CIRCULATION CENTER TO 
17N59W. SHOWERS AND POSSIBLE THUNDERSTORMS ARE IN THE ATLANTIC 
OCEAN FROM 17N TO 20N BETWEEN 56W AND 62W.

THE REST OF THE ATLANTIC OCEAN...
A MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 
26N46W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG 
THUNDERSTORMS ARE WITHIN 60 NM TO 90 NM ON EITHER SIDE OF THE 
LINE FROM 32N48W TO 29N55W TO 26N58W TO TO 22N60W...IN BETWEEN 
THE 32N58W 24N61W TROUGH AND THE 26N46W CYCLONIC CENTER.
A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM A 16N55W CYCLONIC 
CENTER TO 10N60W...TO THE WEST OF THE 54W/55W TROPICAL WAVE. 

$$
MT