000
AXNT20 KNHC 191049
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT SEP 19 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 SATELLITE IMAGERY
THROUGH 1015 UTC.

...SPECIAL FEATURES...
A 1008 MB LOW PRESSURE CENTER IS NEAR 13N40W. IT HAS BEEN MOVING 
WESTWARD 5 KT DURING THE LAST 24 HOURS. NUMEROUS STRONG SHOWERS 
AND THUNDERSTORMS COVER THE AREA FROM 12N TO 15N BETWEEN 41W AND 
44W. SCATTERED MODERATE TO STRONG  SHOWERS AND THUNDERSTORMS 
FROM 10N TO 15N BETWEEN 35W AND 39W. THE CHANCE THAT THIS
SYSTEM MAY BECOME A TROPICAL CYCLONE DURING THE NEXT 48 HOURS
IS MEDIUM. AN UPPER LEVEL TROUGH THAT EXTENDS FROM 32N16W
TO 24N27W TO 19N40W TO 13N46W IS ABOUT 220 NM TO THE NORTHWEST
OF THE LOW CENTER.

...TROPICAL WAVES...

AN EASTERN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 27W/28W TO THE 
SOUTH OF 18N MOVING WESTWARD 10 TO 15 KT. THE ISOLATED MODERATE 
SHOWERS FROM 16N TO 18N BETWEEN 24W AND 32W DO NOT SEEM TO BE 
RELATED TO THIS WAVE. THE SCATTERED MODERATE TO STRONG SHOWERS
AND THUNDERSTORMS FROM 17N TO 20N BETWEEN 19W AND 21W DO NOT
SEEM TO BE RELATED TO THIS WAVE EITHER. THESE AREAS OF 
PRECIPITATION HAVE MAINTAINED THEMSELVES INDEPENDENTLY WITH
RESPECT TO THE WAVE.

A TROPICAL WAVE IS ALONG 92W TO THE SOUTH OF 20N...MOVING ACROSS
THE SOUTHWESTERN GULF OF MEXICO...WESTWARD 10 TO 15 KT. SHOWERS
AND POSSIBLE THUNDERSTORMS WITHIN A 30 NM RADIUS OF 19N96W AT
THE COAST. 

...THE ITCZ...

15N17W 15N25W 13N29W 12N37W 11N44W TO 10N62W INTO NORTHEASTERN 
VENEZUELA. NO SIGNIFICANT DEEP CONVECTIVE PRECIPITATION.

...DISCUSSION...

THE GULF OF MEXICO...
AN UPPER LEVEL TROUGH PASSES THROUGH THE NORTHEASTERN GULF OF 
MEXICO INTO THE EASTERN GULF...TO THE NORTHWESTERN YUCATAN 
PENINSULA TO THE ISTHMUS OF TEHUANTEPEC. DISORGANIZED AND 
ISOLATED MODERATE SHOWERS ARE TO THE EAST OF 90W...AND ACROSS
THE ISTHMUS OF TEHUANTEPEC. AN UPPER LEVEL RIDGE THAT STRETCHES
FROM SOUTH CENTRAL MEXICO BEYOND THE LOWER VALLEY OF TEXAS IS
PUSHING UPPER LEVEL MOISTURE FROM MEXICO AND TEXAS INTO THE GULF 
OF MEXICO TO THE WEST OF 90W.

THE CARIBBEAN SEA...
AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 15N80W...
ABOUT 200 NM TO THE EAST OF THE BORDER OF EASTERN HONDURAS
AND NORTHEASTERN NICARAGUA. CYCLONIC FLOW COVERS THE WHOLE AREA 
TO THE WEST OF 70W. THE STRONG CONVECTIVE PRECIPITATION THAT
WAS ON TOP OF LAKE MARACAIBO IN NORTHWESTERN VENEZUELA HAS
BEEN WEAKENING WITH WARMING CLOUD TOP TEMPERATURES.
UPPER LEVEL CYCLONIC FLOW COVERS THE AREA TO THE NORTH OF 13N
TO THE EAST OF 70W. THIS CYCLONIC FLOW IS RELATED TO THE 
ATLANTIC OCEAN UPPER LEVEL CYCLONIC CENTER THAT IS NEAR 22N60W. 
SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS
ARE FROM 12N TO 16N BETWEEN 79W AND 83W. ISOLATED MODERATE 
SHOWERS ARE TO THE SOUTH OF 24N TO THE EAST OF 86W IN THE GULF 
OF MEXICO IN UPPER LEVEL DIFFLUENT FLOW. THE REST OF THE 
CARIBBEAN SEA TO THE WEST OF 70W CONTAINS ISOLATED MODERATE 
SHOWERS WITH THE UPPER LEVEL 15N80W CYCLONIC CENTER.

THE ATLANTIC OCEAN...
AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 22N60W.
CYCLONIC FLOW AROUND THIS CENTER COVERS THE CARIBBEAN SEA AND
THE ATLANTIC OCEAN TO THE NORTH OF 13N BETWEEN 50W AND 71W.
THE 1012 MB LOW PRESSURE CENTER THAT IS NEAR 26N69W IS THE 
REMNANT OF HURRICANE FRED. A SURFACE TROUGH IS ALONG 69W FROM
24N TO 30N. STRONG CONVECTIVE PRECIPITATION IS WITHIN A 45 NM
RADIUS OF 26N69.5W. ISOLATED MODERATE SHOWERS FROM 16N TO 23N
BETWEEN 57W AND 66W UNDER THE LARGE-SCALE CYCLONIC FLOW.
A SURFACE TROUGH IS ALONG 31N73W 28N76W...ACROSS ABACO ISLAND
IN THE BAHAMAS TO 24N80W. ISOLATED MODERATE SHOWERS COVER THE 
BAHAMAS AND ATLANTIC OCEAN WITHIN 30 NM ON EITHER SIDE OF
THE TROUGH.

$$
MT