000
AXNT20 KNHC 181803
TWDAT 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI APR 18 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 
SECTIONS OF SOUTH AMERICA...AND THE 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 1715 UTC.

...THE ITCZ...

FROM 4N AT THE PRIME MERIDIAN TO 4N12W...CROSSING THE EQUATOR
AT 28W...1S40W...AND ENTERING NORTHEASTERN BRAZIL NEAR 2S51W.
ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE
SOUTH OF 5N BETWEEN THE PRIME MERIDIAN AND 53W. STRONG SHOWERS 
AND THUNDERSTORMS ARE FROM THE EQUATOR TO 1S BETWEEN 48W AND 50W.

...DISCUSSION...

THE GULF OF MEXICO...

A DEEP LAYER TROUGH IS PUSHING CYCLONIC FLOW ACROSS MEXICO NORTH 
OF 25N AND TEXAS. ANTICYCLONIC WIND FLOW ACCOMPANIES AN UPPER 
LEVEL RIDGE THAT EXTENDS FROM THE FLORIDA PANHANDLE TO THE 
YUCATAN CHANNEL...COVERING THE REST OF THE GULF OF MEXICO.
THE DEEP LAYER TROUGH SUPPORTS A COLD FRONT THAT PASSES THROUGH 
THE UPPER TEXAS COAST AND CONTINUES TO THE DEEP SOUTH OF TEXAS.
RAIN CELLS THAT WERE IN THE EXTREME NORTHWESTERN GULF WATERS OFF 
THE MIDDLE AND UPPER TEXAS COASTS HAVE MOVED TO THE LOUISIANA 
COASTAL PLAINS. A FEW NEW CELLS ARE DEVELOPING ALONG THE FRONT.
THE FRONT IS MARKED BY A PROMINENT ROPE-CLOUD IN VISIBLE IMAGERY.
THE FRONT IS FORECAST TO WEAKEN DURING THE NEXT 24 HOURS AND 
STILL MOVE EASTWARD THROUGH 48 HOURS. THE SOUTHERN PART OF THE 
FRONT IS FORECAST TO LINGER OVER SOUTH FLORIDA BY 72 HOURS.

THE CARIBBEAN SEA...

UPPER LEVEL ANTICYCLONIC FLOW WITH A WESTERN CARIBBEAN SEA RIDGE 
COVERS THE AREA WEST OF JAMAICA. DEEP LAYER CYCLONIC FLOW WITH 
THE BERMUDA-TO-16N67W TROUGH COVERS THE REST OF THE AREA EAST OF
JAMAICA. ISOLATED MODERATE SHOWERS FROM 16N TO 17N BETWEEN 83W 
AND 84W ARE IN TRADEWIND LOW CLOUDS MOVING NORTHWESTWARD. 
ISOLATED MODERATE SHOWERS ARE DISSIPATING IN THE EXTREME 
SOUTHWESTERN CORNER OF THE AREA ALONG THE PANAMA/COSTA RICA 
COASTS BETWEEN 81W AND 84W.

THE ATLANTIC OCEAN...

A DEEP LAYER WESTERN ATLANTIC OCEAN TROUGH PASSES OVER BERMUDA 
TO 26N66W INTO THE CARIBBEAN SEA NEAR 16N67W. THE TROUGH SUPPORTS
A COLD FRONT THAT PASSES THROUGH 32N58W TO 31N59W. A STATIONARY 
FRONT CONTINUES FROM 31N59W TO 25N64W TO 20N70W INTO THE 
NORTHWESTERN DOMINICAN REPUBLIC...TO SOUTHWESTERN HAITI. 
ISOLATED MODERATE SHOWERS ARE WITHIN 15 NM TO 30 NM ON EITHER 
SIDE OF THE LINE THROUGH 32N58W TO 27N61W TO 23N65W. SCATTERED 
TO BROKEN LOW AND MIDDLE LEVEL CLOUDS ARE WITHIN 60 NM TO 90 NM 
ON EITHER SIDE OF 20N75W 23N68W 25N64W. DEEP LAYER CYCLONIC FLOW 
AROUND A TROUGH ENTERS THE EASTERN ATLANTIC OCEAN AND IT IS 
NORTH OF 25N EAST OF 35W. THE TROUGH SUPPORTS A COLD FRONT THAT 
PASSES THROUGH NORTHERN MOROCCO AND 32N10W TO 29N24W BEYOND 
32N37W. BROKEN LOW TO MIDDLE LEVEL CLOUDS AND POSSIBLE 
PRECIPITATION ARE WITH THIS FRONT. AN UPPER LEVEL RIDGE IS ALONG 
22N28W 25N39W BEYOND 32N44W. A MIDDLE LEVEL CYCLONIC CIRCULATION 
CENTER APPEARS NEAR 14N38W. UPPER LEVEL WESTERLY-TO-SOUTHWESTERLY
WIND FLOW IS SOUTH OF 12N60W 12N42W 14N30W BEYOND 20N16W.

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