000
AXNT20 KNHC 200610
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI APR 20 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...
CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...
NORTHEASTERN 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0345 UTC.

...THE ITCZ...
10N9W 3N20W 2N30W 1N40W 1N48W...GOING INTO NORTHEASTERN BRAZIL 
NEAR 1S53W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG 
THUNDERSTORMS ARE FROM 3N TO 5N BETWEEN 15W AND 22W. ISOLATED 
MODERATE SHOWERS AND LOCALLY STRONG THUNDERSTORMS ARE ELSEWHERE
SOUTH OF 4N EAST OF 52W.

...DISCUSSION...

THE GULF OF MEXICO...
AN UPPER LEVEL RIDGE EXTENDS FROM THE YUCATAN PENINSULA BEYOND 
THE NORTHWESTERN CORNER OF THE AREA...INTO NORTH TEXAS. AN UPPER 
LEVEL RIDGE ALSO RUNS FROM NORTHERN COLOMBIA/EXTREME NORTHWESTERN
VENEZUELA TOWARD THE NORTHWEST CORNER OF THE CARIBBEAN SEA...TO
THE YUCATAN PENINSULA. IT IS POSSIBLE THAT THIS WHOLE AREA
OF UPPER LEVEL ANTICYCLONIC FLOW IS PART OF THE SAME SYSTEM.
UPPER LEVEL MOISTURE IS WITHIN 400 NM ON EITHER SIDE OF 23N93W
BEYOND 32N98W. ONLY THE SOUTHERNMOST PART OF THE COLD FRONT FROM
24 HOURS AGO IS OBSERVED IN CUBA WEST OF 80W...AND THIS PART OF
THE COLD FRONT IS DISSIPATING WITH TIME. WEAK SURFACE HIGH 
PRESSURE IS BUILDING FROM NORTHWEST-TO-SOUTHEAST ACROSS THE GULF 
OF MEXICO. ISOLATED MODERATE SHOWERS ARE OCCURRING IN INTERIOR
SECTIONS OF MEXICO NORTH OF 18N BETWEEN 96W AND 106W.

THE CARIBBEAN SEA...
AN UPPER LEVEL RIDGE ALSO RUNS FROM NORTHERN COLOMBIA/EXTREME 
NORTHWESTERN VENEZUELA TOWARD THE NORTHWEST CORNER OF THE 
CARIBBEAN SEA...TO THE YUCATAN PENINSULA. AN UPPER LEVEL RIDGE 
EXTENDS FROM THE YUCATAN PENINSULA BEYOND THE NORTHWESTERN 
CORNER OF THE GULF OF MEXICO...INTO NORTH TEXAS. IT IS POSSIBLE 
THAT THIS WHOLE AREA OF UPPER LEVEL ANTICYCLONIC FLOW IS PART
OF THE SAME SYSTEM. A SURFACE RIDGE IS ALONG 16N68W TO 17N63W
OVER THE ISLANDS IMMEDIATELY EAST OF PUERTO RICO...BEYOND 20N54W
IN THE ATLANTIC OCEAN. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS
ARE IN COASTAL COLOMBIA FROM 6N TO 9N BETWEEN 75W AND 78W...NEAR
THE ITCZ...WHICH IS ALONG 8N75W 9N80W. STRONG SHOWERS AND 
THUNDERSTORMS FROM 19/2315 UTC IN NORTHERN COASTAL COLOMBIA...
NORTH OF 10N...HAVE WEAKENED AND LEFT CONVECTIVE DEBRIS CLOUDS.
SCATTERED MODERATE TO STRONG SHOWERS AND THUNDERSTORMS STILL 
EXIST IN NORTHWESTERN VENEZUELA...IN THE ADJACENT AREA TO THE 
NORTHEAST OF LAKE MARACAIBO.

THE ATLANTIC OCEAN...
DEEP LAYER CYCLONIC FLOW COVERS THE AREA NORTH OF 20N WEST OF
40W. THIS SYSTEM SUPPORTS AN ATLANTIC OCEAN COLD FRONT THAT
GOES FROM A 1004 MB 31N67W LOW PRESSURE CENTER TO 28N70W...
THE BAHAMAS NEAR 24N77W. THE COLD FRONT DISSIPATES FROM 24N77W 
SOUTHWESTWARD TO CUBA NEAR 23N80W AND CUBA NEAR 22N83W.
WIDELY SCATTERED MODERATE SHOWERS TO ISOLATED STRONG 
THUNDERSTORMS ARE WITHIN 30 NM TO 60 NM ON EITHER SIDE OF
23N48W 28N44W BEYOND 32N41W. ISOLATED MODERATE SHOWERS ARE
FROM 22N TO 27N BETWEEN 50W AND 62W...AND FROM 27N TO 34N
BETWEEN 58W AND 65W. A SURFACE RIDGE STARTS AT A 1023 MB HIGH 
PRESSURE CENTER NEAR 32N30W AND IT CONTINUES TO 26N38W 21N54W
AND 17N64W IN THE NORTHEASTERN CARIBBEAN SEA. AN UPPER LEVEL 
TROUGH IS IN THE TROPICAL JET STREAM. BROAD WESTERLY FLOW FROM 
VENEZUELA AND GUYANA/SURINAME/AND FRENCH GUIANA TO 3N45W...TO 
THE CAPE VERDE ISLANDS...ACROSS AND BEYOND THE WESTERN SAHARA.
MIDDLE TO UPPER LEVEL DRY AIR/SUBSIDENCE IS WITHIN 300 NM TO
600 NM BETWEEN 30W AND 54W.

$$
MT