000
AXNT20 KNHC 181058
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST FRI DEC 18 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...SPECIAL FEATURES...

...FOR THE GULF OF MEXICO...THE FORECAST INDICATES...THAT IN 6
HOURS OR SO...A COLD FRONT WILL BE ALONG 28N83W 20N93W 18.5N93W.
EXPECT GALE-FORCE NORTHWEST TO NORTH WINDS AND SEA HEIGHTS
RANGING FROM 8 FEET TO 10 FEET TO THE SOUTH OF 21N TO THE WEST
OF THE FRONT TO 94W. GALE-FORCE WINDS ARE FORECAST TO LAST FOR
ABOUT 18 HOURS ONCE THEY START TO BE OBSERVED. PLEASE READ THE
HIGH SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC...AND THE OFFSHORE
FORECAST...MIAOFFNT4/FZNT24 KNHC...FOR MORE DETAILS ABOUT... 

...FOR THE ATLANTIC OCEAN...PLEASE REFER TO THE METEO-FRANCE
HIGH SEAS FORECAST THAT IS LISTED UNDER MARINE...BULLETINS
EXPERTISES...GRAND LARGE...METAREA II...ON THE WEBSITES
WWW.METEO.FR...OR WWW.METEOFRANCE.COM...FOR GALE-FORCE WINDS
THAT ARE FORECAST FOR THE AREA THAT IS CALLED IRVING.

GALE-FORCE WINDS ARE FORECAST TO DEVELOP IN ABOUT 6 HOURS...IN
THE GULF OF TEHUANTEPEC ON THE EASTERN PACIFIC OCEAN SIDE OF
SOUTHERN MEXICO. STORM-FORCE WINDS ARE FORECAST TO DEVELOP IN
ABOUT 18 HOURS IN THE GULF OF TEHUANTEPEC. PLEASE READ THE
EASTERN PACIFIC OCEAN HIGH SEAS FORECAST...MIAHSFEP2/FZPN03
KNHC...AND THE EASTERN PACIFIC OCEAN TROPICAL WEATHER
DISCUSSION...MIATWDEP/AXPZ20 KNHC...FOR MORE DETAILS. 

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

THE ITCZ IS ALONG 04N16W 04N32W 05N34W 03N39W 02N44W. A SURFACE
TROUGH IS ALONG 07N34W 04N36W 02N38W. CONVECTIVE
PRECIPITATION...WIDELY SCATTERED MODERATE TO ISOLATED STRONG
FROM 05N TO 07N BETWEEN 30W AND 40W. ISOLATED MODERATE ELSEWHERE
FROM 10N SOUTHWARD FROM 60W EASTWARD.

...DISCUSSION...

...THE GULF OF MEXICO...

A DEEP LAYER TROUGH IS MOVING THROUGH THE OHIO VALLEY INTO PARTS
OF MISSOURI AND FINALLY INTO LOUISIANA. UPPER LEVEL
SOUTHWESTERLY WIND FLOW COVERS THE GULF OF MEXICO. THE TROUGH IS
SUPPORTING A COLD FRONT THAT PASSES THROUGH THE FLORIDA NEAR
30N84W...TO THE CENTRAL GULF OF MEXICO NEAR 24N90W...INTO THE
SOUTHWESTERN CORNER OF THE GULF OF MEXICO...AT THE NORTHERN PART
OF THE ISTHMUS OF TEHUANTEPEC. A SURFACE RIDGE PASSES THROUGH
THE DEEP SOUTH OF TEXAS...ALONG THE MEXICO COAST...TO THE
ISTHMUS OF TEHUANTEPEC OF SOUTHERN MEXICO. CONVECTIVE
PRECIPITATION...SCATTERED STRONG WITHIN 30 NM ON EITHER SIDE OF
27N83W 26N83W 24N86W...AND FROM 22N TO 23N BETWEEN 86W AND 88W.
ISOLATED MODERATE IS IN PARTS OF THE SOUTHWESTERN CORNER OF THE
GULF OF MEXICO AND INLAND IN SOUTHERN MEXICO NEAR THE BORDER
WITH GUATEMALA FROM 17N TO 18N BETWEEN 91W AND 92W. RAINSHOWERS
ARE POSSIBLE ELSEWHERE IN THE GULF OF MEXICO TO THE NORTHWEST OF
THE 27N83W 24N86W LINE.

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

VFR CONDITIONS ARE BEING REPORTED.

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

IFR CONDITIONS IN FLORIDA AT...PERRY. RAIN AND DRIZZLE AND IFR/
LIFR CONDITIONS ARE BEING REPORTED IN THE NORTHEASTERN PART OF
THE GREATER TAMPA-ST. PETERSBURG METROPOLITAN AREA. IFR
CONDITIONS AND LIGHT RAIN ARE BEING OBSERVED IN SARASOTA.
LIFR CONDITIONS ARE FOUND IN PARTS OF THE FORT MYERS
METROPOLITAN AREA. 

...FROM THE WESTERN SECTIONS OF THE ATLANTIC OCEAN...ACROSS THE
BAHAMAS AND CUBA...INTO THE WESTERN SECTIONS OF THE CARIBBEAN
SEA...INCLUDING CROSSING HISPANIOLA...AND THE REST OF THE
CARIBBEAN SEA...

AN UPPER LEVEL TROUGH EXTENDS FROM A 22N69W ATLANTIC OCEAN
CYCLONIC CIRCULATION CENTER...ACROSS HISPANIOLA...TO 14N74W IN
THE CARIBBEAN SEA...TO EASTERN PANAMA IN THE SOUTHWESTERN CORNER
OF THE CARIBBEAN SEA. LARGE-SCALE UPPER LEVEL CYCLONIC WIND FLOW
COVERS THE CARIBBEAN SEA TO THE SOUTHEAST OF THE LINE THAT RUNS
FROM 21N79W AT THE COAST OF CUBA TO EASTERN COASTAL HONDURAS.
CONVECTIVE PRECIPITATION...BROKEN TO OVERCAST MULTILAYERED
CLOUDS AND POSSIBLE RAINSHOWERS ARE FROM 12N TO 22N BETWEEN 60W
AND 80W...INCLUDING IN EASTERN SECTIONS OF THE DOMINICAN
REPUBLIC. RAINSHOWERS ARE POSSIBLE ALSO IN PATCHES OF CLOUDS
THAT ARE MOVING NORTHWESTWARD...FROM 12N NORTHWARD FROM 80W
WESTWARD. RAINSHOWERS ARE POSSIBLE FROM 10N TO 12N BETWEEN 58W
AND 64W...MOVING WESTWARD FROM THE ATLANTIC OCEAN THROUGH THE
SOUTHEASTERN CORNER OF THE CARIBBEAN SEA.

AN UPPER LEVEL RIDGE EXTENDS FROM GUATEMALA TO THE YUCATAN
PENINSULA AND THE YUCATAN CHANNEL...TO THE STRAITS OF FLORIDA.
AN UPPER LEVEL RIDGE ALSO IS ALONG 61W IN THE EASTERN PART OF
THE CARIBBEAN SEA.

CURRENT OBSERVATIONS...FOR THE DOMINICAN REPUBLIC...FEW
CUMULONIMBUS CLOUDS AND SCATTERED MIDDLE LEVEL CLOUDS ARE IN
SANTO DOMINGO. FEW LOW LEVEL CLOUDS AND SCATTERED MIDDLE LEVEL
CLOUDS ARE IN LA ROMANA AND PUNTA CANA. FEW CUMULONIMBUS CLOUDS
ARE IN SANTIAGO. FEW LOW LEVEL CLOUDS ARE IN PUERTO PLATA.

THE GFS MODEL AT 250 MB SHOWS THAT THE CURRENT UPPER LEVEL
CYCLONIC CIRCULATION CENTER AND TROUGH WILL CONTINUE TO AFFECT
THE AREA FOR THE NEXT 48 HOURS OR SO. THE CYCLONIC CENTER WILL
MOVE ON TOP OF HISPANIOLA AT THE END OF DAY ONE. THE CYCLONIC
CENTER WILL BECOME ELONGATED AND WEAKEN AS AN ORGANIZED CENTER
DURING DAY TWO. EXPECT NORTHWESTERLY WIND FLOW BY THE END OF DAY
TWO. THE GFS MODEL AT 500 MB SHOWS THAT EAST-TO-SOUTHEAST WIND
FLOW WILL BE MOVING ACROSS HISPANIOLA FOR THE NEXT 48 HOURS. AN
INVERTED TROUGH WILL REMAIN ACROSS THE AREA. THE GFS MODEL AT
700 MB SHOWS THAT EAST TO SOUTHEAST WIND FLOW WILL MOVE ACROSS
HISPANIOLA DURING THE NEXT 48 HOURS. EXPECT ALSO A FEW SHORT-
LIVED INVERTED TROUGHS TO CROSS HISPANIOLA DURING THE NEXT 48
HOURS.

...THE REST OF THE ATLANTIC OCEAN... 

AN ATLANTIC OCEAN UPPER LEVEL TROUGH PASSES THROUGH 32N35W TO
24N41W AND 20N45W. A COLD FRONT PASSES THROUGH 32N30W TO 26N40W
24N50W 24N58W. THE COLD FRONT IS DISSIPATING FROM 24N58W TO
25N65W. A PRE-FRONTAL TROUGH IS ALONG 30N28W 24N36W. CONVECTIVE
PRECIPITATION...ISOLATED MODERATE WITHIN 30 NM TO 45 NM ON
EITHER SIDE OF THE LINE THAT PASSES THROUGH 32N28W TO 29N32W.
RAINSHOWERS ARE POSSIBLE...TO THE NORTH AND NORTHWEST OF THE
LINE THAT PASSES THROUGH 32N23W 20N38W 14N49W 14N60W 27N80W.
CLOUDINESS AND POSSIBLE PRECIPITATION...THAT ARE RELATED TO THE
GULF OF MEXICO FRONTAL BOUNDARY...ARE TO THE NORTHWEST OF
32N77W 28N81W. 

SURFACE ANTICYCLONIC WIND FLOW IS TO THE NORTH AND NORTHWEST OF
THE 32N32W 25N64W COLD FRONT BETWEEN 45W AND 70W. A SURFACE
RIDGE ALSO EXTENDS FROM A 1027 MB HIGH PRESSURE CENTER THAT IS
NEAR 33N56W TO 29N70W...ACROSS THE NORTHWESTERN BAHAMAS OF GRAND
BAHAMA ISLAND AND GREAT ABACO...TO 24N85W IN THE SOUTHEASTERN
GULF OF MEXICO. 

A SURFACE RIDGE PASSES THROUGH WESTERN ALGERIA NEAR 28N07W...
ACROSS THE CANARY ISLANDS...TO 23N31W 19N50W AND 22N65W. 
 
FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE

$$ 
MT