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Atlantic Tropical Weather Discussion (Text)

000
AXNT20 KNHC 071156
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SAT DEC 07 2013

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 
1115 UTC.

...SPECIAL FEATURES...                                           

...ATLC GALE WARNING...
.ATLC COLD FRONT FROM 31N35W TO 19N53W THEN SHEAR LINE TO 
18N64W. N OF 27.5N BETWEEN 42W AND 51W NW TO N WINDS 30 TO 35 
KT. SEAS 13 TO 21 FT IN MERGING NE AND NW SWELL. ELSEWHERE N OF 
25N W OF FRONT TO 42W SW TO W WINDS 20 TO 30 KT. SEAS 8 TO 17 FT 
IN MERGING NE AND NW SWELL. ELSEWHERE N OF 25N W OF FRONT TO 54W 
N OF 25N NW TO N WINDS 20 TO 30 KT. SEAS 8 TO 12 FT IN PRIMARILY 
NE SWELL. N OF 25N WITHIN 120 NM E OF FRONT S TO SW WINDS 20 TO 
25 KT. SEAS 8 TO 10 FT. N OF FRONT AND SHEAR LINE TO 26N BETWEEN 
54W AND 68W NE WINDS 20 TO 25 KT. SEAS 8 TO 12 FT. REMAINDER OF 
AREA FROM 18N TO 26N BETWEEN 62W AND 72W WINDS 20 KT OR LESS. 
SEAS 8 TO 10 FT IN NE SWELL.

...GULF OF MEXICO GALE WARNING...
.GULF OF MEXICO COLD FRONT FROM 30N86.5W TO 19N96W. FROM 21N TO 
24N W OF 96W N WINDS 25 TO 35 KT. SEAS 8 TO 10 FT. ELSEWHERE W 
OF FRONT N WINDS 20 TO 25 KT. SEAS 8 TO 10 FT W OF 93W. 

...THE ITCZ/THE MONSOON TROUGH...                                

THE MONSOON TROUGH PASSES THROUGH THE COASTAL SECTIONS OF GUINEA 
NEAR 10N14W TO 8N19W. THE ITCZ CONTINUES FROM 8N19W TO 4N27W AND 
1N37W. CONVECTIVE PRECIPITATION...WIDELY SCATTERED MODERATE TO 
ISOLATED STRONG TO THE SOUTH OF 10N MOSTLY BETWEEN 22W AND 43W. 
BROKEN TO OVERCAST MULTILAYERED CLOUDS AND OTHER RAINFALL COVER 
THE ATLANTIC OCEAN FROM 500 NM TO 750 NM TO THE WEST OF THE LINE 
FROM 23N34W TO 13N44W TO 5N51W. THIS PRECIPITATION IS RELATED TO 
THE CENTRAL ATLANTIC OCEAN-TO-CARIBBEAN SEA MIDDLE LEVEL TO 
UPPER LEVEL TROUGH...AND THE 41W SURFACE TROUGH AND THE 51W 
SURFACE TROUGH. ONE ATLANTIC OCEAN SURFACE TROUGH IS ALONG 41W 
FROM 7N TO 14N. A SECOND ATLANTIC OCEAN SURFACE TROUGH IS ALONG 
51W FROM 7N TO 14N.

...DISCUSSION...

THE GULF OF MEXICO...

A COLD FRONT PASSES THROUGH THE FLORIDA PANHANDLE BETWEEN 
86W/87W...INTO THE NORTH CENTRAL GULF OF MEXICO NEAR 28N90W... 
TO 25N93W IN THE WEST CENTRAL GULF OF MEXICO...TO 19N96W IN THE 
SOUTHWESTERN CORNER OF THE GULF OF MEXICO ALONG THE MEXICO 
COAST. THE FRONT CURVES TO 18N97W AND 21N99W IN MEXICO. A 
STATIONARY FRONT CONTINUES FROM 21N99W TO 27N102W...AND 
NORTHWESTWARD BEYOND THE TEXAS BIG BEND. BROKEN TO OVERCAST 
MULTILAYERED CLOUDS ARE TO THE WEST AND NORTHWEST OF THE 31N85W 
25N88W AND 20N91W. CONVECTIVE PRECIPITATION...WIDELY SCATTERED 
MODERATE TO ISOLATED STRONG FROM 20N TO 23N BETWEEN 91W AND 94W. 
RAINSHOWERS ARE POSSIBLE ALSO IN THE GULF OF MEXICO THAT IS TO 
THE EAST OF THE COLD FRONT. MIDDLE LEVEL TO UPPER LEVEL 
SOUTHWESTERLY WIND FLOW IS MOVING ACROSS THE AREA OF THE FRONT...
ON TOP OF THE COLD FRONT.

MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC WIND FLOW SPANS THE 
GULF OF MEXICO. A RIDGE PASSES THROUGH 32N76W IN THE ATLANTIC 
OCEAN...TO AN ANTICYCLONIC CIRCULATION CENTER THAT IS NEAR 
26N82W ALONG THE SOUTHWESTERN COAST OF FLORIDA. COMPARATIVELY 
DRIER AIR IN SUBSIDENCE...AS SEEN IN WATER VAPOR IMAGERY...
COVERS THE GULF OF MEXICO. 

AN ATLANTIC OCEAN 1028 MB HIGH PRESSURE CENTER IS NEAR 32N63W. A 
SURFACE RIDGE EXTENDS FROM THE 1028 MB HIGH CENTER...TO 
30N75W...ACROSS FLORIDA FROM 28N TO 29N...INTO THE GULF OF 
MEXICO NEAR 26N90W.

FOR THE OFFSHORE OIL PLATFORM SITES THAT ARE TO THE NORTH OF 27N 
TO THE WEST OF 87W/88W...

LOW CLOUD CEILINGS AND THE LOWEST VISIBILITY OF 4 MILES WITH FOG 
COVER THE ICAO STATIONS THAT ARE IMMEDIATELY OFF THE TEXAS GULF 
COAST. LOW CLOUD CEILINGS AND VISIBILITIES OF 4 TO 6 MILES WITH 
FOG COVER THE REST OF THE ICAO STATIONS THAT ARE TO THE WEST OF 
90W. LOW CLOUD CEILINGS AND VISIBILITIES OF 1 MILE OR LESS WITH 
FOG COVER THE REST OF THE ICAO STATIONS...THOSE THAT ARE ALONG 
AND TO THE EAST OF 90W. VISIBILITIES OF THREE MILES OR LESS WITH 
FOG CONTINUE AT THE EASTERN END OF THE AREA...AND AT THE WESTERN 
END OF THE FORECAST AREA.

FOR THE COASTAL PLAINS OF THE U.S.A. FROM TEXAS TO FLORIDA...

LOW CLOUD CEILINGS COVER COASTAL TEXAS BEHIND THE CURRENT 
WESTERN GULF OF MEXICO COLD FRONT. LIGHT RAIN IS OCCURRING IN 
THE DEEP SOUTH OF TEXAS. THE LOW CLOUD CEILINGS CONTINUE INTO 
SOUTHERN LOUISIANA AND MISSISSIPPI. THE RAINFALL HAS ENDED FOR 
THE MOMENT IN MISSISSIPPI. THE LOW CLOUD CEILINGS AND LIGHT RAIN 
CONTINUE INTO ALABAMA. LOW CLOUD CEILINGS COVER THE FLORIDA 
PANHANDLE. LIGHT RAIN HAS BEEN FALLING NEAR PANAMA CITY. 
VISIBILITIES OF 1 MILE OR LESS WITH FOG CONTINUE FROM 
APALACHICOLA TO TALLAHASSEE TO PERRY. THE TAMPA EXECUTIVE 
GENERAL AIRPORT...ICAO STATION KVDF...IS REPORTING A VISIBILITY 
OF 2 MILES OR LESS WITH FOG. THE FOG HAS LIFTED FOR THE MOMENT 
AT THE ST.PETERSBURG/CLEARWATER INTERNATIONAL AIRPORT...ICAO 
STATION KPIE. THE VISIBILITY IN PUNTA GORDA IS ONE MILE WITH 
FOG.

PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC...AND 
THE OFFSHORE FORECAST...MIAOFFNT4/FZNT24 KNHC...FOR MORE DETAILS 
ABOUT THE COLD FRONT FROM 29N90W TO 26N93W AND 19N97W. EXPECT 
NORTH WINDS 20 TO 25 KNOTS...EXCEPT WIND SPEEDS TO 30 KNOTS 
WITHIN 60 NM OF THE COAST FROM 22N TO 26N. SEA HEIGHTS 8 TO 10 
FEET. 

FROM THE CENTRAL ATLANTIC OCEAN...INTO THE NORTHEASTERN CORNER 
OF THE CARIBBEAN SEA...TO VENEZUELA...

A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM AN ATLANTIC 
OCEAN 33N41W CYCLONIC CIRCULATION CENTER...TO 26N42W...TO 
24N53W....TO A CARIBBEAN SEA 16N62W CYCLONIC CIRCULATION CENTER. 
THE TROUGH CONTINUES FROM 16N62W TO 8N67W IN VENEZUELA. THE 
TROUGH SUPPORTS A COLD FRONT THAT PASSES THROUGH 31N35W TO 
24N40W TO 19N52W. A DISSIPATING COLD FRONT CONTINUES FROM 19N52W 
TO 18N60W TO THE SOUTHEASTERN COAST OF PUERTO RICO. CONVECTIVE 
PRECIPITATION IN THE ATLANTIC OCEAN...WIDELY SCATTERED MODERATE 
TO ISOLATED STRONG TO THE NORTH OF 23N BETWEEN 30W AND 37W. 
ISOLATED MODERATE TO THE NORTH OF 28N BETWEEN 37W AND 46W. 
CONVECTIVE PRECIPITATION IN THE CARIBBEAN SEA...SCATTERED 
MODERATE TO ISOLATED STRONG FROM 15N TO 21N BETWEEN 54W AND 
65W...FROM THE ATLANTIC OCEAN INTO THE CARIBBEAN SEA. 24-HOUR 
RAINFALL TOTALS IN INCHES FOR THE PERIOD ENDING AT 06/1200 
UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND 
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...WERE 1.65 IN SAN 
JUAN PUERTO RICO...AND 1.44 IN ST. THOMAS. 

...HISPANIOLA...

MIDDLE LEVEL TO UPPER LEVEL NORTHEASTERLY WIND FLOW COVERS THE 
AREA. THIS WIND REGIME IS ASSOCIATED WITH THE CYCLONIC WIND FLOW 
THAT IS MOVING AROUND THE 16N62W MIDDLE LEVEL TO UPPER LEVEL 
CYCLONIC CIRCULATION CENTER.

SCATTERED LOW CLOUDS ARE BEING REPORTED ACROSS HISPANIOLA. 
COMPARATIVELY DRIER AIR IN SUBSIDENCE...AS SEEN IN WATER VAPOR 
IMAGERY...COVERS THE AREA. 

24-HOUR RAINFALL TOTALS IN INCHES FOR THE PERIOD ENDING AT 
06/1200 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND 
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...WERE 1.65 IN SAN 
JUAN PUERTO RICO...AND 1.44 IN ST. THOMAS. THIS PRECIPITATION IS 
RELATED TO THE MIDDLE LEVEL TO UPPER LEVEL TROUGH AND 16N62W 
CYCLONIC CIRCULATION CENTER.

THE GFS FORECAST FOR 250 MB SHOWS THAT NORTHERLY-TO-
NORTHEASTERLY WIND FLOW WILL PASS ON TOP OF HISPANIOLA DURING 
THE NEXT 48 HOURS. CYCLONIC WIND FLOW FROM A TROUGH WILL COVER 
THE CARIBBEAN SEA TO THE EAST OF 80W. THE GFS FORECAST FOR 500 
MB AND FOR 700 MB SHOWS THAT NORTHEASTERLY TO EASTERLY WIND FLOW 
WILL PASS ON TOP OF HISPANIOLA FOR THE NEXT 48 HOURS.

THE REST OF THE CARIBBEAN SEA...

MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW COVERS THE 
CARIBBEAN SEA TO THE EAST OF 70W. MIDDLE LEVEL TO UPPER LEVEL 
ANTICYCLONIC WIND FLOW COVERS THE CARIBBEAN SEA FROM 
70W WESTWARD.

RAINSHOWERS ARE POSSIBLE ELSEWHERE IN THE CARIBBEAN SEA TO THE 
SOUTH OF 20N...IN AREAS OF BROKEN LOW LEVEL TO MIDDLE LEVEL 
CLOUDS. 

THE MONSOON TROUGH IS ALONG 10N74W IN COLOMBIA TO 10N84W IN 
COSTA RICA...BEYOND 10N86W INTO THE EASTERN PACIFIC OCEAN. 
CONVECTIVE PRECIPITATION...SCATTERED TO NUMEROUS STRONG IN ONE 
CELL OF PRECIPITATION IN EASTERN PANAMA FROM 8N TO 9N BETWEEN 
78W AND 79W. OTHER RAINSHOWERS ARE POSSIBLE TO THE SOUTH OF 10N 
IN THE SOUTHWESTERN CORNER OF THE CARIBBEAN SEA.

PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC...AND 
THE OFFSHORE FORECAST...MIAOFFNT3/FZNT23 KNHC...FOR MORE DETAILS 
ABOUT...NORTHEAST WINDS 25 TO 30 KNOTS AND SEA HEIGHTS 8 TO 11 
FEET FROM 11N TO 14N BETWEEN 73W AND 77W. NORTHEAST TO EAST 
WINDS AND SEA HEIGHTS 8 TO 11 FEET ELSEWHERE FROM 11N TO 17.5N 
BETWEEN 69W AND 79W. EXPECT ALSO WINDS 20 KNOTS OR LESS AND SEA 
HEIGHTS 8 TO 10 FEET FROM 10N TO 17N BETWEEN 79W AND 81W. A 
SECOND AREA OF INTEREST CONSISTS OF NORTHEAST WINDS 20 TO 25 
KNOTS AND SEA HEIGHTS TO 8 FEET TO THE SOUTHWEST OF THE WINDWARD 
PASSAGE...TO THE NORTH OF 19N BETWEEN 73W AND 76W.

THE REST OF THE ATLANTIC OCEAN...

A 1028 MB HIGH PRESSURE CENTER IS NEAR 32N63W. A SURFACE RIDGE 
EXTENDS FROM THE 1028 MB HIGH CENTER...TO 30N75W...ACROSS 
FLORIDA FROM 28N TO 29N...INTO THE GULF OF MEXICO NEAR 26N90W.

A SURFACE RIDGE EXTENDS FROM THE CANARY ISLANDS TO A 1017 MB 
HIGH PRESSURE CENTER THAT IS NEAR 21N28W...TO 21N35W.

PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC...FOR 
MORE DETAILS ABOUT NORTHEAST TO EAST WINDS 20 TO 25 KNOTS AND 
SEA HEIGHTS TO 9 FEET TO THE SOUTH OF 23N BETWEEN 70W AND 
75W...INCLUDING IN THE WINDWARD PASSAGE. A SECOND AREA OF 
INTEREST CONSISTS OF WINDS 20 KNOTS OR LESS AND SEA HEIGHTS 8 TO 
9 FEET TO THE SOUTH OF 20N AND TO THE EAST OF THE LINE FROM 
20N56W TO 13N52W TO 07N42W. 

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

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MT