000
AXNT20 KNHC 040607
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT THU MAY 04 2006

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 0515 UTC.

...THE ITCZ...
ITCZ 7N11W 2N20W...CROSSING THE EQUATOR AT 26W...AND EVENTUALLY 
TO THE EQUATOR AT 50W. SCATTERED MODERATE TO STRONG SHOWERS AND 
THUNDERSTORMS ARE FOUND FROM 2S TO 2N BETWEEN 32W AND 46W.
ISOLATED MODERATE SHOWERS TO LOCALLY STRONG THUNDERSTORMS ARE 
ELSEWHERE FROM THE EQUATOR TO 3N EAST OF 10W...AND FROM THE 
EQUATOR TO 6N BETWEEN 45W AND 52W.

...DISCUSSION...
THE GULF OF MEXICO...
UPPER LEVEL SOUTHWESTERLY WIND FLOW MOVES FROM THE EASTERN 
PACIFIC OCEAN...ACROSS THE SOUTHERN HALF OF BAJA CALIFORNIA
INTO THE WESTERN SECTIONS OF MEXICO. UPPER LEVEL SOUTHERLY
AND SOUTHWESTERLY FLOW MOVES FROM THE EASTERN PACIFIC OCEAN
JUST NORTH OF THE ITCZ PRECIPITATION ACROSS SOUTHEASTERN
MEXICO INTO THE YUCATAN CHANNEL AND THE SOUTHERN AND 
SOUTHEASTERN SECTIONS OF THE GULF OF MEXICO. BROAD AND GRADUAL 
MIDDLE TO UPPER LEVEL ANTICYCLONIC FLOW IS SEEN ON WATER VAPOR 
IMAGERY AND IN THE 04/0000 UTC CIMSS SATELLITE DERIVED WIND
DATA. MIDDLE TO UPPER LEVEL DRY AIR FROM SUBSIDENCE IS FOUND
IN MOST AREAS EXCEPT FOR THE SOUTHEASTERN CORNER OF THE AREA.
UPPER LEVEL BLOW-OFF MOISTURE FROM ALREADY-EXISTING OR 
DISSIPATING THUNDERSTORMS IS WEST OF 93W. THE THUNDERSTORMS ARE
DEVELOPING NEAR A TROUGH FROM WEST TEXAS TO INTERIOR MEXICO. 
NORTH OF 25N/26N. A RIDGE RUNS FROM THE ATLANTIC WATERS NEAR
25N68W...ACROSS THE NORTHERN BAHAMAS AND LAKE OKEECHOBEE...TO 
A 1019 MB EASTERN GULF OF MEXICO HIGH PRESSURE CENTER NEAR 
27N85W.

THE CARIBBEAN SEA...
MIDDLE TO UPPER LEVEL ANTICYCLONIC FLOW COVERS THE AREA THANKS
TO SOUTHWESTERLY-TO-WESTERLY FLOW...FROM THE EASTERN PACIFIC
OCEAN TO THE NORTH CENTRAL CARIBBEAN SEA AND EASTWARD.
THIS FLOW REGIME IS ON THE PERIPHERY OF THE UPPER LEVEL TROPICAL 
ATLANTIC OCEAN-TO-NORTHERN SOUTH AMERICA AND CARIBBEAN SEA 
RIDGE. THE TROPICAL RIDGE IS PUSHING UPPER LEVEL MOISTURE AND 
CLOUDINESS HAVE SPREAD NORTHWARD TO 20N ACROSS AN AREA OF MIDDLE 
TO UPPER LEVEL DRY AIR. A 1007 MB LOW PRESSURE CENTER IS IN 
NORTHERN COLOMBIA NEAR 8N75W. SCATTERED TO NUMEROUS STRONG
SHOWERS AND THUNDERSTORMS HAVE DEVELOPED FROM 5N TO 10N BETWEEN 
74W AND 78W.

THE ATLANTIC OCEAN...
DEEP LAYER CYCLONIC FLOW FROM A TROUGH COVERS THE ATLANTIC 
WATERS NORTH OF 20N WEST OF 57W. THIS IS THE SAME TROUGH WHICH 
STILL SUPPORTS THE ATLANTIC COLD FRONT WHICH NOW PASSES THROUGH 
32N50W TO 25N60W. A TROUGH CONTINUES FROM 25N60W TO THE 
NORTHEASTERN ISLANDS NEAR 16N65W ABOUT 140 NM SOUTHEAST OF 
PUERTO RICO. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE 
SHOWERS AND THUNDERSTORMS ARE WITHIN 120 NM ON EITHER SIDE OF 
26N53W 23N60W 20N62W TO 16N65W. SCATTERED MODERATE TO ISOLATED 
STRONG SHOWERS AND THUNDERSTORMS ARE WITHIN 90 NM ON EITHER SIDE 
OF 32N47W 26N54W. A TROUGH CONTINUES FROM 24N60W TO 20N66W TO 
THE MONA PASSAGE. THIS PATTERN OF CLOUDS AND POSSIBLE 
PRECIPITATION WILL BE THE SAME FOR THAT PART OF THE ATLANTIC 
WATERS AND THE CARIBBEAN SEA AREA FROM PUERTO RICO AND THE 
ISLANDS EASTWARD UNTIL THE DEEP LAYER TROUGH EITHER EXITS THE 
REGION OR JUST DISSIPATES. A MIDDLE TO UPPER LEVEL RIDGE PASSES
THROUGH 32N42W TO 25N48W. A MIDDLE TO UPPER LEVEL TROUGH RUNS 
FROM 11N39W TO 18N32W 25N27W. SURFACE HIGH PRESSURE IS EAST OF 
THE COLD FRONT/TROUGH. A 1024 MB HIGH CENTER IS NEAR 30N35W.
SURFACE ANTICYCLONIC FLOW IS NORTH OF 6N BETWEEN THE COAST
OF AFRICA AND 48W.

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MT