[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 120550
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0515 UTC.

...THE ITCZ...

FROM SIERRA LEONE NEAR 8N13W TO 6N20W 2N30W...CROSSING THE
EQUATOR ALONG 35W AND REMAINING FROM 1S TO THE EQUATOR BETWEEN
35W AND 44W...REACHING EXTREME NORTHEASTERN BRAZIL NEAR 2N51W.
SCATTERED TO NUMEROUS STRONG RAINSHOWERS AND THUNDERSTORMS ARE
IN SIERRA LEONE FROM 8N TO 10N BETWEEN 12W AND 14W INCLUDING
IN THE COASTAL WATERS...AND ELSEWHERE FROM 3S TO 4N BETWEEN 34W
AND 42W...AND FROM 2S TO 4N BETWEEN 44W AND 52W FROM THE BRAZIL
COAST TO COASTAL FRENCH GUIANA. ISOLATED MODERATE RAINSHOWERS
AND POSSIBLE THUNDERSTORMS ARE ELSEWHERE FROM 2N TO AFRICA
BETWEEN THE PRIME MERIDIAN AND 7W...AND FROM 3S TO 2N BETWEEN
24W AND 37W.

...DISCUSSION...

THE GULF OF MEXICO...
A DEEP LAYER TROUGH SPANS THE U.S.A. MIDWEST. THIS 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 1016 MB HIGH PRESSURE CENTER THAT IS NEAR
29N84W.

THE 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 AND NORTHWESTERN VENEZUELA FROM 4N TO 11N BETWEEN 70W
AND 75W...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 BORDER OF HAITI
AND THE DOMINICAN REPUBLIC TO SOUTHEASTERN NICARAGUA. SCATTERED
TO BROKEN LOW CLOUDS ARE TO THE SOUTH OF THE LINE THAT GOES FROM
SOUTHWESTERN HAITI TO EASTERN HONDURAS.

THE 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. A 995 MB LOW PRESSURE CENTER IS NEAR 37N61W. A SURFACE
TROUGH CURVES AWAY FROM THE 995 MB CENTER TO 32N59W. A COLD
FRONT EVENTUALLY EXTENDS FROM THE CYCLONIC ENVELOPE AND IT
PASSES THROUGH 32N49W TO 28N50W TO 22N57W. A DISSIPATING COLD
FRONT CONTINUES FROM 22N57W TO 21N64W AND 21N71W NEAR THE
SOUTHEASTERN BAHAMAS. RAINSHOWERS ARE POSSIBLE TO THE NORTH OF
24N BETWEEN 53W AND 80W...AND WITHIN 120 TO 180 NM ON EITHER
SIDE OF 18N62W 23N50W 27N46W BEYOND 32N46W. A WEAK SURFACE-
TO-LOW LEVEL TROUGH APPEARS TO BE ALONG 14N50W 18N43W...
TO A 1016 MB LOW PRESSURE CENTER THAT IS NEAR 22N42W...
TO 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 TROUGH 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





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