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Atlantic Tropical Weather Discussion (Text)

000
AXNT20 KNHC 312354
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SAT JAN 31 2015

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2315 UTC.

...SPECIAL FEATURES...

...GALE-FORCE WINDS ARE FORECAST FOR THE ATLANTIC OCEAN AND FOR 
THE CARIBBEAN SEA...

...THE ATLANTIC OCEAN GALE WARNING...

THE 12-HOUR FORECAST CONSISTS OF A COLD FRONT FROM 31N53W TO 
25N55W TO 18N63W. EXPECT GALE-FORCE WEST-TO-NORTHWEST WINDS AND 
SEA HEIGHTS RANGING FROM 12 FEET TO 20 FEET TO THE NORTH OF 30N 
BETWEEN 55W AND 65W. THE 24-HOUR FORECAST CONSISTS OF A COLD 
FRONT FROM 31N47W TO 25N52W TO 20N62W. EXPECT GALE-FORCE WEST-TO-
NORTHWEST WINDS AND SEA HEIGHTS RANGING FROM 14 FEET TO 22 FEET 
TO THE NORTH OF 29N TO THE WEST OF FRONT TO 57W. 

A SECOND AREA OF A GALE WARNING IS IN THE ATLANTIC OCEAN. THE 42-
HOUR FORECAST CONSISTS OF A COLD FRONT ALONG THE SOUTHEASTERN 
COAST OF THE U.S.A. EXPECT GALE-FORCE SOUTHWEST WINDS AND SEA 
HEIGHTS RANGING FROM 10 FEET TO 13 FEET TO THE NORTH OF 30N TO 
THE WEST OF 77W.

...THE CARIBBEAN SEA GALE WARNING...

THE 12-HOUR FORECAST CONSISTS OF GALE-FORCE NORTHEAST WINDS AND 
SEA HEIGHTS RANGING FROM 9 FEET TO 13 FEET FROM 10.5N TO 13N 
BETWEEN 74W AND 77W. THIS EVENT WILL LAST ONLY FOR 6 HOURS. 
ANOTHER GALE-FORCE WIND EVENT WILL TAKE PLACE AGAIN 18 HOURS 
AFTER THE FIRST ONE.

PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC...AND 
THE OFFSHORE FORECAST...MIAOFFNT3/FZNT23 KNHC...FOR MORE DETAILS.

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

THE MONSOON TROUGH PASSES THROUGH COASTAL SECTIONS OF LIBERIA 
NEAR 6N11W TO 4N17W. THE ITCZ CONTINUES FROM 4N17W TO 1N30W... 
CROSSING THE EQUATOR ALONG 44W...TO THE COAST OF BRAZIL NEAR 
1S47W. CONVECTIVE PRECIPITATION...ISOLATED MODERATE FROM 5N 
SOUTHWARD BETWEEN 35W AND 50W. RAINSHOWERS ARE POSSIBLE 
ELSEWHERE FROM 10N SOUTHWARD FROM 60W EASTWARD. 

...DISCUSSION...

...THE GULF OF MEXICO...

MIDDLE LEVEL TO UPPER LEVEL SOUTHWEST WIND FLOW IS MOVING ACROSS 
THE GULF OF MEXICO. COMPARATIVELY DRIER AIR IN SUBSIDENCE IS 
APPARENT IN WATER VAPOR IMAGERY FROM 26N SOUTHWARD.

A COLD FRONT PASSES THROUGH THE ATLANTIC OCEAN...ACROSS THE 
BAHAMAS NEAR 23N75W...ALONG THE NORTHERN COAST OF CUBA...INTO 
THE CENTRAL GULF OF MEXICO NEAR 24N80W. A WARM FRONT CONTINUES 
FROM 24N80W TO THE MIDDLE TEXAS GULF COAST NEAR 28N...AND INLAND 
TO 28N100W IN TEXAS. CONVECTIVE PRECIPITATION...RAINSHOWERS ARE 
POSSIBLE FROM 22N NORTHWARD.

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

LOW LEVEL CLOUD CEILINGS ARE BEING REPORTED AT THE FOLLOWING 
ICAO PLATFORM SITES...KEMK...KHQI...KGHB...KGRY...KATP...KIPN...
AND KMIS.

LOW LEVEL CLOUD CEILINGS AND WEATHER...FOR THE COASTAL PLAINS OF 
THE U.S.A. FROM THE DEEP SOUTH OF TEXAS TO FLORIDA...

LOW LEVEL CLOUD CEILINGS COVER THE DEEP SOUTH OF TEXAS. LOW 
LEVEL CLOUD CEILINGS AND AREAS OF RAIN COVER THE AREAS FROM PORT 
LAVACA TO THE HOUSTON METROPOLITAN AREA. LOW LEVEL CLOUD 
CEILINGS COVER SOUTH CENTRAL COASTAL SECTIONS OF LOUISIANA... 
SUCH AS FROM PATTERSON TO INTRACOASTAL CITY...IN NEW IBERIA AND 
IN LAFAYETTE.

...THE CARIBBEAN SEA...

MIDDLE LEVEL TO UPPER LEVEL SOUTHWESTERLY WIND FLOW MOVES FROM 
THE EASTERN PACIFIC OCEAN NEAR 6N86W...ACROSS THE AREA 
FROM NICARAGUA TO PANAMA...INTO AND THROUGH THE CARIBBEAN SEA. 
THE SOUTHWESTERLY WIND FLOW MERGES WITH MIDDLE LEVEL TO UPPER 
LEVEL WESTERLY WIND FLOW ALONG 80W. COMPARATIVELY DRIER AIR IN 
SUBSIDENCE IS APPARENT IN WATER VAPOR IMAGERY COVERS THE ENTIRE 
AREA. SOME MIDDLE LEVEL TO UPPER LEVEL NORTHWESTERLY WIND FLOW 
MOVES ACROSS THE BAHAMAS AND THE ATLANTIC OCEAN...ACROSS 
HISPANIOLA AND PUERTO RICO...THROUGH THE NORTHEASTERN CORNER OF 
THE CARIBBEAN SEA. A MIDDLE LEVEL TO UPPER LEVEL RIDGE COVERS 
THE NORTHWESTERN CORNER OF THE AREA...FROM 15N NORTHWARD FROM 
80W WESTWARD.

SCATTERED TO BROKEN LOW LEVEL CLOUDS AND AREAS OF RAIN COVER 
PARTS OF CENTRAL AMERICA FROM GUATEMALA TO THE YUCATAN PENINSULA.

RAINSHOWERS ARE POSSIBLE ACROSS THE OPEN WATERS OF THE CARIBBEAN 
SEA...IN SCATTERED TO BROKEN LOW LEVEL CLOUDS AND SURFACE-TO-LOW 
LEVEL TRADE WIND FLOW. 24-HOUR RAINFALL TOTALS IN INCHES FOR THE 
PERIOD ENDING AT 31/1200 UTC...ACCORDING TO THE PAN AMERICAN 
TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 
KNHC...IS 0.45 IN TRINIDAD...0.17 IN MONTEGO BAY IN 
JAMAICA...0.03 IN SAN JUAN IN PUERTO RICO...AND 0.01 IN CURACAO 
AND IN GUADELOUPE. 

THE MONSOON TROUGH IS NOT PRESENT IN THE SOUTHWESTERN CORNER OF 
THE CARIBBEAN SEA.

...HISPANIOLA...

UPPER LEVEL NORTHWESTERLY WIND FLOW IS CROSSING HISPANIOLA. 
MIDDLE LEVEL NORTH-TO-NORTHEAST WIND FLOW ALSO IS CROSSING 
HISPANIOLA.

CLOUD CONDITIONS AND PREVAILING WEATHER...FOR PORT-AU-PRINCE IN 
HAITI...A LOW LEVEL CLOUD CEILING IS BEING REPORTED. FOR THE 
DOMINICAN REPUBLIC...FEW CUMULONIMBUS CLOUDS AND OTHER SCATTERED 
LOW LEVEL CLOUDS ARE IN BARAHONA. RAINSHOWERS AND MULTILAYERED 
CLOUD CEILINGS ARE BEING REPORTED IN SANTO DOMINGO. RAINSHOWERS 
AND A LOW LEVEL CLOUD CEILING ARE BEING OBSERVED IN LA ROMANA. 
RAINSHOWERS AND SCATTERED MULTILAYERED CLOUDS ARE BEING REPORTED 
IN PUNTA CANA. RAINSHOWERS AND MULTILAYERED CLOUD CEILINGS ARE 
BEING OBSERVED IN SANTIAGO. RAINSHOWERS AND AN OVERCAST LOW 
LEVEL CLOUD CEILING ARE BEING REPORTED IN PUERTO PLATA.

THE GFS MODEL FORECAST FOR 250 MB SHOWS THAT SOUTHWEST-WEST-TO-
NORTHWEST WIND FLOW WILL MOVE ACROSS HISPANIOLA. A RIDGE WILL BE 
ON TOP OF CENTRAL AMERICA. THE GFS MODEL FORECAST FOR 500 MB 
SHOWS THAT A RIDGE WILL BE PRESENT FROM COLOMBIA INTO THE 
NORTHWESTERN CORNER OF THE CARIBBEAN SEA. NORTHWESTERLY WIND 
FLOW WILL CROSS HISPANIOLA. THE WIND FLOW WILL SHIFT TO 
SOUTHWESTERLY FOR A 12 HOURS OR SO AS SOME PART OF THE RIDGE 
SHIFTS TO THE EAST. NORTHWEST WIND FLOW WILL RETURN FOR 6 TO 12 
HOURS. THE 48-HOUR FORECAST PERIOD WILL END WITH AN ANTICYCLONIC 
CIRCULATION CENTER ON TOP OF HISPANIOLA. THE GFS MODEL FORECAST 
FOR 700 MB SHOWS THAT EAST-TO-SOUTHEAST WIND FLOW WILL MOVE 
ACROSS HISPANIOLA. A RIDGE WILL BE PRESENT FROM 21N62W IN THE 
ATLANTIC OCEAN TO SOUTHEASTERN CUBA.

...THE ATLANTIC OCEAN... 

A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N63W TO 
26N63W. A FIRST COLD FRONT PASSES THROUGH 32N51W TO 27N54W TO 
23N57W. THE COLD FRONT IS DISSIPATING FROM 23N57W TO 21N60W. A 
SECOND COLD FRONT PASSES THROUGH 32N59W TO 25N66W...THROUGH THE 
BAHAMAS NEAR 23N75W...ALONG THE NORTHERN COAST OF CUBA...INTO 
THE CENTRAL GULF OF MEXICO NEAR 24N80W. A WARM FRONT CONTINUES 
FROM 24N80W TO THE MIDDLE TEXAS GULF COAST NEAR 28N...AND INLAND 
TO 28N100W IN TEXAS. THE 24-HOUR RAINFALL TOTAL IN INCHES FOR 
THE PERIOD ENDING AT 31/1200 UTC...ACCORDING TO THE PAN AMERICAN 
TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC... 
IS 0.06 IN BERMUDA. CONVECTIVE PRECIPITATION...ISOLATED MODERATE 
TO LOCALLY STRONG FROM 26N NORTHWARD BETWEEN 47W AND 52W. 
RAINSHOWERS ARE POSSIBLE WITHIN 120 NM TO THE WEST OF THE LINE 
THAT PASSES THROUGH 32N55W 28N60W 23N70W 22N77W. 

A SURFACE RIDGE EXTENDS FROM A SOUTH CAROLINA 1029 MB HIGH 
PRESSURE CENTER THAT IS NEAR 33N81W...TO 28N76W AND TO 25N73W. 

A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM A FIRST 31N33W 
CYCLONIC CIRCULATION CENTER TO A SECOND 27N34W CYCLONIC 
CIRCULATION CENTER...TO 14N35W AND 10N36W. A SURFACE TROUGH IS 
ALONG 28N35W 23N39W. CONVECTIVE PRECIPITATION...WIDELY SCATTERED 
TO SCATTERED MODERATE FROM 26N TO 29N BETWEEN 30W AND 35W.

A SURFACE RIDGE PASSES THROUGH 32N26W TO 21N30W AND TO 8N30W. 
SURFACE ANTICYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN FROM 8N 
NORTHWARD BETWEEN AFRICA AND THE 28N35W-TO-23N39W SURFACE 
TROUGH.  

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

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MT