000
AXNT20 KNHC 141101
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1015 UTC.

...THE ITCZ...
FROM 4N7W AT THE SOUTHERN COAST OF LIBERIA...TO 2N10W...
CROSSING THE EQUATOR ALONG 22W...TO 1S30W 2S40W AND GOING
INTO NORTHEASTERN BRAZIL NEAR 3S45W. NUMEROUS STRONG SHOWERS
AND THUNDERSTORMS FROM THE EQUATOR TO 5N BETWEEN 7W AND 11W.
THE CLOUD TOP TEMPERATURES RANGE FROM -80C TO -88C AND THE CLOUD
TOPS ARE REACHING AT LEAST 50000 FEET. ISOLATED MODERATE SHOWERS 
TO LOCALLY STRONG THUNDERSTORMS ARE SOUTH OF 3N BETWEEN 15W AND 
26W. 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 THE CENTRAL U.S.A. INTO 
THE CENTRAL GULF OF MEXICO IS DRIVING A GULF OF MEXICO COLD 
FRONT AND PRE-FRONTAL TROUGH. THE TROUGH EXTENDS FROM THE FLORIDA
PANHANDLE TO THE CENTRAL GULF WATERS CURVING TO A 1007 MB LOW
PRESSURE CENTER IN THE SOUTHWESTERN CORNER OF THE AREA NEAR
21.5N 93.5W. THE COLD FRONT EXTENDS FROM THE MISSISSIPPI/ALABAMA
BORDER TO 28N90W TO 23.5N97W...ABOUT 150 NM TO THE SOUTH OF THE
TEXAS/MEXICO BORDER. THE COLDEST CLOUD TOP TEMPERATURES OF AT 
LEAST -71C AND CLOUD TOPS REACHING ABOUT 43000 FEET ARE FROM 27N 
TO 29N BETWEEN 84W AND 86W. CLOUD TOP TEMPERATURES ARE NEAR -70C 
AND CLOUD TOPS RANGE FROM 42000 FEET TO 50000 FEET IN THE 
NORTHEASTERN GULF OF MEXICO. 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 
32N50W TO 27N56W TO 24N65W. SHOWERS ARE POSSIBLE WITHIN 15 NM
TO 30 NM ON EITHER SIDE OF THE COLD FRONT...AND TO THE NORTH OF 
28N BETWEEN 50W AND 58W. BROAD SURFACE ANTICYCLONIC FLOW IS TO 
THE NORTH OF 15N BETWEEN AFRICA AND THE 32N03W 24N65W COLD 
FRONT. BROAD LARGE-SCALE UPPER LEVEL ANTICYCLONIC FLOW IS TO
THE SOUTH OF 26N TO THE EAST OF 60W. THE SOUTHERN BOUNDARY OF
AN EASTERN ATLANTIC OCEAN DEEP LAYER TROUGH REACHES MOROCCO.
THIS TROUGH SUPPORTS A COLD FRONT THAT PASSES THROUGH 32N13W
TO 31N21W TO 32N30W.

$$
MT