000
AXNT20 KNHC 121114
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
805 AM EDT THU MAY 12 2011

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1015 UTC.

...ITCZ...

FROM SIERRA LEONE NEAR 8N13W TO 4N23W 2N31W 1N36W 2N42W.
A SURFACE TROUGH IS ALONG 5N44W TO THE EQUATOR ALONG 46W.
SCATTERED TO NUMEROUS STRONG RAINSHOWERS AND THUNDERSTORMS ARE 
FROM 2S ALONG THE BRAZIL COAST TO 6N IN THE COASTAL WATERS OF 
BRAZIL AND FRENCH GUIANA BETWEEN 42W AND 53W. SCATTERED MODERATE
RAINSHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE FROM 2N TO 
AFRICA BETWEEN THE PRIME MERIDIAN AND 6W...AND ELSEWHERE FROM
2S TO 3N BETWEEN 28W AND 40W. RAINSHOWERS ARE POSSIBLE ELSEWHERE
TO THE SOUTH OF 8N BETWEEN AFRICA AND 35W.

...DISCUSSION...

GULF OF MEXICO...
CYCLONIC FLOW FROM A DEEP LAYER TROUGH SPANS THE MIDWEST OF
THE U.S.A. THE TROUGH SUPPORTS A STILL-DEVELOPING FRONTAL 
BOUNDARY IN THE CENTRAL U.S.A. THAT FRONT IS FORECAST TO REACH 
THE TEXAS GULF COAST DURING THE NEXT 48 HOURS OR SO. UPPER LEVEL
ANTICYCLONIC WIND FLOW MOVES FROM THE EASTERN PACIFIC OCEAN AREA 
FROM 10N TO 24N BETWEEN 100W AND 110W...ACROSS MEXICO AND PARTS 
OF CENTRAL AMERICA INTO THE GULF OF MEXICO AND ADJACENT 
CARIBBEAN SEA. THE UPPER LEVEL FLOW REACHES 90W IN THE GULF OF 
MEXICO. BROAD MIDDLE LEVEL TO UPPER LEVEL CYCLONIC FLOW THAT IS 
RELATED TO AN ATLANTIC OCEAN TROUGH COVERS THE REST OF THE AREA 
THAT IS TO THE EAST OF 90W. BROAD SURFACE ANTICYCLONIC FLOW 
COVERS THE AREA THAT IS TO THE NORTH OF 25N TO THE EAST OF 
90W...MOVING AROUND A 1015 MB HIGH PRESSURE CENTER THAT IS
NEAR 28N84W.

CARIBBEAN SEA...
A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 24N76W IN 
THE BAHAMAS...ACROSS EASTERN CUBA TO 13N80W IN THE SOUTHWESTERN 
CORNER OF THE AREA. ISOLATED MODERATE RAINSHOWERS TO POSSIBLE 
THUNDERSTORMS COVER THE AREA FROM NORTHWESTERN NICARAGUA TO 
NORTHWESTERN GUATEMALA...IN BROAD SURFACE LOW PRESSURE AND UPPER 
LEVEL ANTICYCLONIC FLOW. RAINSHOWERS AND THUNDERSTORMS ARE IN 
COLOMBIA...NORTHWESTERN VENEZUELA...AND PANAMA AND SURROUNDING 
COASTAL WATERS FROM 3N TO 12N BETWEEN 70W AND 80W...IN BROAD 
MONSOONAL CYCLONIC FLOW. THE SURFACE PRESSURE GRADIENT IS WEAK 
ACROSS THE AREA. HIGH CLOUDS COVER THE AREA TO THE EAST OF THE 
LINE THAT GOES FROM THE SOUTHERN DOMINICAN REPUBLIC TO 14N78W
TO SOUTHEASTERN NICARAGUA. SCATTERED TO BROKEN LOW CLOUDS ARE
TO THE SOUTH OF THE LINE THAT GOES FROM SOUTHWESTERN HAITI TO 
EASTERN HONDURAS.

ATLANTIC OCEAN...
BROAD MIDDLE LEVEL TO UPPER LEVEL CYCLONIC FLOW COVERS THE AREA 
TO THE WEST OF 48W. IT IS POSSIBLE THAT MULTIPLE CYCLONIC 
CIRCULATION CENTERS ARE EMBEDDED IN THE LARGER-SCALE CYCLONIC 
FLOW...REALLY ONLY TO THE NORTH OF 30N TO THE WEST OF 50W.
A 995 MB LOW PRESSURE CENTER IS NEAR 37N61W. A SURFACE TROUGH 
CURVES AWAY FROM THE 995 MB CENTER TO 31N58W. A COLD FRONT 
EVENTUALLY EXTENDS FROM THE CYCLONIC ENVELOPE AND IT REACHES
31N49W. A STATIONARY FRONT CONTINUES FROM 31N49W TO 28N50W 
25N52W AND 22N56W. A DISSIPATING STATIONARY FRONT CONTINUES FROM
22N56W TO 21N67W. RAINSHOWERS ARE POSSIBLE TO THE NORTH OF 24N 
BETWEEN 50W AND 80W...AND WITHIN 120 TO 180 NM ON EITHER SIDE OF 
19N63W 22N55W 25N45W BEYOND 33N46W. A WEAK LOW LEVEL-TO-MIDDLE
LEVEL TROUGH APPEARS TO BE ALONG 14N50W 18N43W 22N42W 24N37W TO 
25N31W BEYOND 31N29W. CLOUDS AND RAINSHOWERS ARE POSSIBLE WITHIN 
60 NM ON EITHER SIDE OF THE LINE...AND FROM 21N TO 25N BETWEEN 
36W AND 42W. THIS WEAK FEATURE IS IN BROAD SURFACE ANTICYCLONIC 
FLOW THAT IS TO THE NORTH OF 10N TO THE EAST OF 50W. BROAD UPPER 
LEVEL CYCLONIC FLOW IS TO THE NORTH OF 16N TO THE EAST OF 30W.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$

MT