000
AXNT20 KNHC 140554
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT TUE APR 14 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 0000 UTC SURFACE ANALYSIS AND GOES0-12 SATELLITE
IMAGERY THROUGH 0315 UTC...AND METEOSAT-9 IMAGERY THROUGH
0530 UTC.

...THE ITCZ...
FROM 5N8W AT THE COAST OF LIBERIA...TO 1N16W...CROSSING THE 
EQUATOR ALONG 28W...TO 1S40W AND GOING INTO NORTHEASTERN BRAZIL 
NEAR 2S44W. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS FROM 1N
TO 4N BETWEEN 5W AND 11W. THE CLOUD TOP TEMPERATURES ARE NEAR
-87C AND THE CLOUD TOPS ARE REACHING 51000 FEET. ISOLATED
MODERATE SHOWERS TO LOCALLY STRONG THUNDERSTORMS ARE WITHIN
30 NM ON EITHER SIDE OF 3N12W 2N17W TO THE EQUATOR ALONG 22W.
ISOLATED AND DISORGANIZED MODERATE SHOWERS ARE ELSEWHERE TO
THE SOUTH OF 7N BETWEEN 25W AND 54W. SOME OF THE SHOWERS ARE
IN THE COASTAL WATERS OF BRAZIL AND FRENCH GUIANA.

...DISCUSSION...

THE GULF OF MEXICO...
A DEEP LAYER TROUGH THAT EXTENDS FROM ILLINOIS TO MISSOURI TO
TEXAS/LOUISIANA IS DRIVING A GULF OF MEXICO COLD FRONT AND 
PRE-FRONTAL TROUGH. THE TROUGH EXTENDS FROM THE MISSISSIPPI/
ALABAMA BORDER TO 27N90W AND CURVING TO A 1007 MB LOW PRESSURE 
CENTER IN THE SOUTHWESTERN CORNER OF THE AREA NEAR 21N95W.
THE COLD FRONT EXTENDS FROM SOUTH-CENTRAL COASTAL LOUISIANA TO
THE LOWER TEXAS GULF COAST. THE COLDEST CLOUD TOP TEMPERATURES
OF AT LEAST -71C AND CLOUD TOPS REACHING ABOUT 43000 FEET ARE
FROM 28N TO 29N BETWEEN 86W AND 88W. CLOUD TOP TEMPERATURES
RANGING FROM -67C TO -71C AND CLOUD TOPS REACHING 48000 FEET
AND 51000 FEET ARE IN THE ATLANTIC OCEAN WATERS TO THE EAST OF 
NORTHEASTERN FLORIDA AND SOUTHEASTERN GEORGIA FROM 29N TO 32N
BETWEEN 79W AND 81W. POSSIBLE SHOWERS TRAIL AT THE END OF THE
OTHER AREAS OF PRECIPITATION FROM 24N TO 27N BETWEEN 87W AND 90W.
AN UPPER LEVEL RIDGE IS ALONG 82W.

THE CARIBBEAN SEA...
UPPER LEVEL ANTICYCLONIC FLOW COVERS THE AREA TO THE WEST OF
74W THANKS TO THE UPPER LEVEL 82W RIDGE THAT ALSO SPANS THE GULF 
OF MEXICO. A SEPARATE AREA OF MIDDLE LEVEL TO UPPER LEVEL 
ANTICYCLONIC FLOW DROPS SOUTHWARD FROM THE ATLANTIC OCEAN FROM
THE NORTHEASTERN CORNER OF THE AREA TO 28N BETWEEN 57W AND 75W.
UPPER LEVEL SOUTHERLY AND SOUTHWESTERLY WIND FLOW MOVES FROM
NORTHERN SOUTH AMERICA...ACROSS THE EASTERN CARIBBEAN SEA 
ISLANDS INTO THE ATLANTIC OCEAN. A 24-HOUR RAINFALL TOTAL OF
0.35 INCHES IN GUADELOUPE WAS RECORDED ENDING AT 14/0000 UTC.
THIS RAINFALL AMOUNT MOST PROBABLY WAS ASSOCIATED WITH THE
SHOWERS ACROSS THE EASTERN CARIBBEAN SEA ISLANDS DURING THE
MORNING HOURS OF YESTERDAY 13 APRIL.
 
THE ATLANTIC OCEAN...
UPPER LEVEL ANTICYCLONIC FLOW IS SPILLING INTO THE WESTERN 
ATLANTIC OCEAN FROM THE 82W GULF OF MEXICO RIDGE. A SEPARATE 
AREA OF MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC FLOW DROPS 
SOUTHWARD FROM THE ATLANTIC OCEAN FROM THE NORTHEASTERN CORNER
OF THE AREA TO 28N BETWEEN 57W AND 75W. A CENTRAL ATLANTIC OCEAN 
DEEP LAYER TROUGH SUPPORTS THE COLD FRONT THAT PASSES THROUGH
32N53W TO 28N57W TO 25N62W. ISOLATED MODERATE SHOWERS ARE TO THE 
NORTH OF 30N BETWEEN 50W AND 53W. SHOWERS ARE POSSIBLE WITHIN
15 NM TO 30 NM ON EITHER SIDE OF THE COLD FRONT. BROAD SURFACE 
ANTICYCLONIC FLOW IS TO THE NORTH OF 15N BETWEEN AFRICA AND THE 
32N53W 25N62W COLD FRONT. BROAD LARGE-SCALE UPPER LEVEL 
ANTICYCLONIC FLOW IS TO THE SOUTH OF 26N TO THE EAST OF 60W. 

$$
MT