000
AXNT20 KNHC 181143
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
705 AM EST FRI NOV 18 2011 

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...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1115 UTC.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 51W/52W FROM 10N
TO 19N. THE WAVE IS MOVING THROUGH THE AREA OF A MIDDLE LEVEL
TO UPPER LEVEL TROUGH. NUMEROUS STRONG RAINSHOWERS AND 
THUNDERSTORMS ARE WITHIN 30 TO 60 NM ON EITHER SIDE OF 13N51W 
16N49W 20N47W. SCATTERED STRONG RAINSHOWERS AND THUNDERSTORMS 
ALSO ARE FROM 5N TO 12N BETWEEN 39W AND 48W. IT IS NOT EASY
IN THIS CASE TO DIFFERENTIATE BETWEEN PRECIPITATION THAT IS
JUST RELATED TO THE TROPICAL WAVE...AND PRECIPITATION THAT
JUST IS RELATED TO THE MIDDLE LEVEL TO UPPER LEVEL TROUGH.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH CURVES THROUGH WESTERN SENEGAL NEAR 14N17W
TO 10N19W. THE ITCZ CONTINUES FROM 10N19W TO 6N30W AND 6N47W.
ISOLATED MODERATE TO LOCALLY STRONG RAINSHOWERS ARE ELSEWHERE
FROM 2N TO 9N BETWEEN AFRICA AND 40W. UPPER LEVEL DIFFLUENT
WIND FLOW IS ON TOP OF THE AREA OF THE PRECIPITATION.

...DISCUSSION...

THE GULF OF MEXICO...

THE DEEP LAYER TROUGH IS RIGHT IN THE MIDDLE OF THE GULF OF 
MEXICO. THE TROUGH SUPPORTS THE COLD FRONT THAT PASSES THROUGH 
THE ATLANTIC OCEAN NEAR 32N69W...TO THE FLORIDA EAST COAST ALONG 
27N JUST TO THE SOUTH OF LAKE OKEECHOBEE...TO 22N89W IN THE 
SOUTH CENTRAL GULF. THE FRONT BECOMES STATIONARY NEAR 22N89W
AND IT CONTINUES INTO THE SOUTHWESTERN CORNER OF THE AREA AND
THE ISTHMUS OF TEHUANTEPEC OF SOUTHERN MEXICO. RAINSHOWERS ARE 
POSSIBLE WITHIN 90 NM TO THE EAST AND SOUTHEAST OF THE FRONT 
FROM THE ATLANTIC OCEAN INTO THE GULF OF MEXICO AND IN THE 
ISTHMUS OF TEHUANTEPEC. A SURFACE RIDGE HAS BUILT INTO THE 
COASTAL PLAINS FROM TEXAS TO MEXICO...THROUGH THE LOWER VALLEY 
OF TEXAS...TO 21N98W AND 18N96W. GALE FORCE WINDS ARE BEING 
OBSERVED IN THE GULF OF TEHUANTEPEC ON THE EASTERN PACIFIC
OCEAN SIDE OF MEXICO.

THE CARIBBEAN SEA...

A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM A 19N55W 
CYCLONIC CIRCULATION CENTER TO 14N60W TO THE EAST OF 
MARTINIQUE...TO 13N65W IN THE SOUTHEASTERN CORNER OF THE AREA. 
UPPER LEVEL SOUTHWESTERLY TO WESTERLY WIND FLOW CROSSES THE 
NORTHERN PART OF VENEZUELA...WHERE AREAS OF RAINSHOWERS WERE
OCCURRING DURING THE LATE NIGHT AND EARLY MORNING HOURS OF 
TODAY. AN UPPER LEVEL INVERTED TROUGH IS ALONG 77W/78W FROM 17N 
TO THE SOUTH OF JAMAICA...TO 12N. THE MONSOON TROUGH GOES FROM 
12N73W AT THE COLOMBIA COAST TO 11N79W TO 10N80W...AND ACROSS 
COSTA RICA ALONG 10N...INTO THE EASTERN PACIFIC OCEAN. ISOLATED 
MODERATE RAINSHOWERS ARE TO THE SOUTH OF 13N TO THE WEST OF 74W. 
RAINSHOWERS ARE POSSIBLE ELSEWHERE IN THE SURFACE TRADEWIND
FLOW THAT IS MOVING THROUGH THE AREA.

THE ATLANTIC OCEAN...

A COLD FRONT PASSES THROUGH THE ATLANTIC OCEAN NEAR 32N73W...TO 
FLORIDA JUST TO THE NORTH OF LAKE OKEECHOBEE...AND THEN INTO THE 
SOUTH CENTRAL GULF OF MEXICO. RAINSHOWERS ARE POSSIBLE WITHIN
90 NM TO THE EAST AND SOUTHEAST OF THE FRONT. A MIDDLE LEVEL TO 
UPPER LEVEL TROUGH IS ALONG 29N51W TO ONE CYCLONIC CIRCULATION 
CENTER THAT IS NEAR 26N52W...TO A SECOND CYCLONIC CENTER THAT IS
NEAR 19N55W...BEYOND 14N60W INTO THE SOUTHEASTERN CARIBBEAN SEA. 
A SURFACE TROUGH IS ALONG 30N52W 21N53W. BROKEN TO OVERCAST 
MULTILAYERED CLOUDS AND POSSIBLE PRECIPITATION ARE ELSEWHERE 
FROM 20N TO 30N BETWEEN 40W AND 55W. AN UPPER LEVEL TROUGH IS 
MOVING THROUGH MOROCCO...THE WESTERN SAHARA...AND MAURITANIA.
NO SIGNIFICANT DEEP CONVECTIVE PRECIPITATION IS APPARENT IN 
SATELLITE IMAGERY ALONE. BROAD SURFACE ANTICYCLONIC WIND FLOW 
COVERS THE ATLANTIC OCEAN TO THE EAST OF TROPICAL WAVE AND THE 
30N52W 21N53W SURFACE TROUGH.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
MT