000
AXNT20 KNHC 151054
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE SEP 15 2009

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1015 UTC.

...TROPICAL WAVES...

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 67W/68W TO THE SOUTH OF
15N MOVING WEST ABOUT 10 KT. THIS WAVE IS MOVING THROUGH THE 
AREA OF UPPER LEVEL CYCLONIC FLOW THANKS TO THE CYCLONIC CENTER 
THAT IS ABOUT 60 NM TO THE SOUTHEAST OF PUERTO RICO.
NO SIGNIFICANT DEEP CONVECTIVE PRECIPITATION JUST IS
ASSOCIATED WITH THIS WAVE.

...THE ITCZ...

ALONG 8N/9N BETWEEN SIERRA LEONE AND NORTHEASTERN VENEZUELA.
ISOLATED MODERATE SHOWERS ARE WITHIN 120 NM ON EITHER SIDE OF 
8N13W 8N30W 8N43W 10N53W 12N60W.

...DISCUSSION...

THE GULF OF MEXICO...
A MIDDLE TO UPPER LEVEL TROUGH PASSES THROUGH MISSISSIPPI/ALABAMA
INTO THE NORTH CENTRAL GULF OF MEXICO...INTO THE WEST CENTRAL
GULF OF MEXICO. THE STRONG SHOWERS AND THUNDERSTORMS IN MEXICO
FROM SIX HOURS AGO HAVE DISSIPATED. ISOLATED MODERATE SHOWERS 
ARE TO THE EAST OF 90W...TO THE EAST OF A SURFACE TROUGH THAT IS
ALONG 87W/88W TO THE NORTH OF 27N. A COLD FRONT HAS MADE INTO 
THE NORTHWESTERN GULF WATERS...A WELL-DEFINED LINE OF CLOUDS IN
THE SHORTWAVE INFRARED SATELLITE IMAGERY MARKS THIS FRONT QUITE 
WELL. 

THE CARIBBEAN SEA...
AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS ABOUT 70 NM TO THE 
SOUTHEAST OF PUERTO RICO. CYCLONIC FLOW AROUND THIS CENTER 
COVERS THE CARIBBEAN SEA AND A SMALL PART OF THE ATLANTIC OCEAN
FROM 11N TO 22N BETWEEN 60W AND 70W. SHOWERS ARE POSSIBLE WITHIN 
300 NM OF PUERTO RICO IN THE SOUTHERN SEMICIRCLE. AN UPPER LEVEL
INVERTED TROUGH RUNS FROM THE CENTRAL YUCATAN PENINSULA BEYOND 
15N93W IN MEXICO JUST TO THE WEST OF SOUTHERN GUATEMALA INTO
THE EASTERN PACIFIC OCEAN. ONE CELL OF PRECIPITATION IS WITHIN
A 30 NM RADIUS OF 20N92W IN THE SOUTHWESTERN CORNER OF THE GULF 
OF MEXICO. UPPER LEVEL NORTHERLY-TO-NORTHEASTERLY WIND FLOW 
MOVES ACROSS HISPANIOLA AND CUBA IN BETWEEN THE TWO AREAS OF 
UPPER LEVEL CYCLONIC FLOW. ISOLATED MODERATE SHOWERS ARE TO THE 
NORTH OF 18N BETWEEN 70W AND 84W.

THE ATLANTIC OCEAN...
A DEEP LAYER WESTERN ATLANTIC OCEAN TROUGH SUPPORTS A COLD FRONT
THAT PASSES THROUGH 32N64W TO A 1012 MB LOW PRESSURE CENTER THAT 
IS NEAR 29N72W. THE COLD FRONT CONTINUES FROM THE LOW CENTER TO 
THE BAHAMAS NEAR 23N75W. A TROUGH EXTENDS FROM THE LOW CENTER TO
26N74W AND ANDROS ISLAND. STRONG SHOWERS AND THUNDERSTORMS ARE 
WITHIN A 30 NM RADIUS OF 26N72W AND 23N74W. POSSIBLE SHOWERS ARE 
ELSEWHERE WITHIN 120 NM ON EITHER SIDE OF THE LINE THAT PASSES 
THROUGH 32N60W TO 29N67W TO 22N78W. AN UPPER LEVEL TROUGH PASSES 
THROUGH 32N28W TO 28N40W TO A SMALL 23N49W CYCLONIC CENTER TO 
11N48W. DISORGANIZED SHOWERS AND ISOLATED MODERATE THUNDERSTORMS 
COVER THE AREA FROM 18N TO 23N BETWEEN 37W AND 48W. THE 1013 MB 
REMNANT LOW PRESSURE CENTER OF FRED IS NEAR 20N45W. A SECOND 
1013 MB LOW PRESSURE CENTER IS JUST TO THE WEST OF THE CAPE 
VERDE ISLANDS NEAR 15N28W. STRONG SHOWERS AND THUNDERSTORMS ARE 
WITHIN A 60 NM RADIUS OF 16N30W. WARMING CLOUD TOP TEMPERATURES 
AND POSSIBLY REMNANT SHOWERS ARE FROM 16N TO 18N BETWEEN 26W AND 
29W.

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MT