Tropical Weather Discussion
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000
AXNT20 KNHC 241158
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SAT JAN 24 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
1115 UTC.

...SPECIAL FEATURES...

...GALE-FORCE WINDS FOR THE ATLANTIC OCEAN...

A COLD FRONT IS APPROACHING THE FLORIDA EAST COAST FROM THE
WEST. SOUTH-TO-SOUTHWEST GALE-FORCE WINDS ARE BEING EXPERIENCED
NOW IN THE ATLANTIC OCEAN TO THE NORTH OF 29N TO THE WEST OF
76W. EXPECT SEA HEIGHTS IN THIS AREA TO RANGE FROM 8 FEET TO 13
FEET. THE GALE-FORCE WINDS ARE FORECAST TO CONTINUE FOR THE NEXT
18 HOURS OR SO. 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 BORDER SECTIONS OF
SIERRA LEONE AND LIBERIA NEAR 7N11W...TO 5N16W. THE ITCZ
CONTINUES FROM 5N16W TO 3N23W AND 1N30W...AND 1N38W. CONVECTIVE
PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG FROM 1N TO
6N BETWEEN 29W AND 41W.

A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM A 28N24W
CYCLONIC CIRCULATION CENTER...TO 23N34W 16N43W TO 7N54W. BROKEN
TO OVERCAST MULTILAYERED CLOUDS ARE WITHIN 275 NM TO 400 NM ON
EITHER SIDE OF THE LINE FROM 3N47W TO 6N36W TO 11N30W...AND
BEYOND 17N16W.

...DISCUSSION...

...THE GULF OF MEXICO...

MIDDLE LEVEL TO UPPER LEVEL SOUTHWEST WIND FLOW IS MOVING ACROSS
THE GULF OF MEXICO. MULTILAYERED MOISTURE IS MOVING ACROSS THE
OPEN WATERS OF THE GULF OF MEXICO.

A 700 MB TROUGH PASSES THROUGH SOUTHWESTERN GEORGIA TO 27N86W IN
THE GULF OF MEXICO...TO 23N89W...AND INTO THE SOUTHWESTERN
CORNER OF THE GULF OF MEXICO. THE INLAND CENTRAL U.S.A. MIDDLE
LEVEL TO UPPER LEVEL TROUGH THAT WAS ABOUT 300 NM TO THE
NORTHWEST OF THE 700 MB TROUGH HAS BEEN MOVING EASTWARD AND IT
HAS BEEN MOVING MORE IN PHASE WITH THE 700 MB TROUGH DURING THE
LAST 6 HOURS OR SO.

A COLD FRONT EXTENDS FROM A 1007 MB SOUTHWESTERN GEORGIA LOW
PRESSURE CENTER...THROUGH THE FLORIDA BIG BEND...THROUGH THE
EASTERN GULF OF MEXICO...TO THE NORTHERN YUCATAN PENINSULA...TO
THE SOUTHERN PART OF MEXICO THAT IS BETWEEN ITS BORDER WITH
GUATEMALA AND THE ISTHMUS OF TEHUANTEPEC. CONVECTIVE
PRECIPITATION...SCATTERED TO NUMEROUS STRONG FROM 23N TO 25N
BETWEEN 82W AND 84W. SCATTERED MODERATE TO ISOLATED STRONG
ELSEWHERE IN THE ATLANTIC OCEAN...IN FLORIDA...AND IN THE
NORTHWESTERN CORNER OF THE CARIBBEAN SEA WITHIN 90 NM ON EITHER
SIDE OF THE LINE THAT PASSES THROUGH 32N76W...TO 28N80W TO
24N83W AND TO 20N87W.

GALE-FORCE WINDS ARE BEING EXPERIENCED IN THE GULF OF
TEHUANTEPEC ON THE EASTERN PACIFIC OCEAN SIDE OF SOUTHERN
MEXICO. A SURFACE RIDGE PASSES THROUGH THE DEEP SOUTH OF
TEXAS...TO A MEXICO COASTAL PLAINS 1030 MB HIGH PRESSURE CENTER
THAT IS NEAR 23N99W...INTO THE ISTHMUS OF TEHUANTEPEC OF
SOUTHERN MEXICO. 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.

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...KHHV...KEMK...KGUL...KHQI...KGBK...
KVQT...KGHB...KGRY...KATP...KIPN...KIKT...KVOA...AND KVKY.

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

A LOW LEVEL CLOUD CEILING IS AROUND THE NORTHWESTERN PERIPHERY
OF LAKE PONTCHARTRAIN. CLEAR SKIES/CLEARING SKIES ARE ELSEWHERE
AROUND LAKE PONTCHARTRAIN. A LOW LEVEL CLOUD CEILING COVERS GULF
SHORES ALABAMA. CLEARING SKIES ARE ELSEWHERE IN COASTAL ALABAMA
TO THE WEST OF GULF SHORES. LOW LEVEL CLOUD CEILINGS COVER THE
FLORIDA PANHANDLE FROM PERRY WESTWARD. MULTILAYERED CLOUD
CEILINGS AND RAINSHOWERS WITH THUNDER COVER THE FLORIDA WEST
COAST FROM BROOKSVILLE TO THE TAMPA-ST.PETERSBURG METROPOLITAN
AREA... AND TO SARASOTA...AND FROM PUNTA GORDA TO NAPLES. MIDDLE
LEVEL CLOUD CEILINGS COVER THE KEY WEST METROPOLITAN AREA.

...THE CARIBBEAN SEA...

AN UPPER LEVEL RIDGE EXTENDS FROM NORTH CENTRAL VENEZUELA...
ACROSS NORTHEASTERN COLOMBIA...INTO THE NORTHWESTERN CORNER OF
THE CARIBBEAN SEA. LARGE-SCALE ANTICYCLONIC WIND FLOW SPANS THE
CARIBBEAN SEA. MIDDLE LEVEL NORTHERLY WIND FLOW COVERS THE AREA
THAT IS FROM 76W EASTWARD.

AN UPPER LEVEL RIDGE ALSO IS ALONG 76W FROM CUBA NORTHWARD.

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 24/0000 UTC...ACCORDING TO THE PAN AMERICAN
TEMPERATURE AND PRECIPITATION TABLES ARE...0.23 IN
GUADELOUPE...AND 0.04 IN CURACAO.

THE MONSOON TROUGH IS ALONG 5N75W IN COLOMBIA...BEYOND 7N90W
INTO THE EASTERN PACIFIC OCEAN. NO SIGNIFICANT DEEP CONVECTIVE
PRECIPITATION IS RELATED TO THE MONSOON TROUGH IN THE
SOUTHWESTERN CORNER OF THE CARIBBEAN SEA.

...HISPANIOLA...

UPPER LEVEL NORTHWESTERLY WIND FLOW IS CROSSING HISPANIOLA.
LARGE-SCALE ANTICYCLONIC WIND FLOW SPANS THE CARIBBEAN SEA.

CLOUD CONDITIONS AND PREVAILING WEATHER...FOR THE DOMINICAN
REPUBLIC...FEW LOW LEVEL CLOUDS COVER THE AREAS FROM BARAHONA TO
SANTO DOMINGO TO LA ROMANA AND TO PUNTA CANA. SCATTERED LOW
LEVEL CLOUDS ARE IN SANTIAGO. FEW LOW LEVEL CLOUDS ARE IN PUERTO
PLATA.

THE GFS MODEL FORECAST FOR 250 MB SHOWS THAT NORTHWEST-TO-WEST
WIND FLOW WILL MOVE ACROSS HISPANIOLA...WITH BROAD ANTICYCLONIC
WIND FLOW...AND A RIDGE FROM COLOMBIA INTO THE NORTHWESTERN
CORNER OF THE CARIBBEAN SEA. THE GFS MODEL FORECAST FOR 500 MB
SHOWS THAT AN ANTICYCLONIC CIRCULATION CENTER IS FORECAST TO
START THE 48-HOUR FORECAST CYCLE NEAR 20N81W...MOVING TO
HISPANIOLA AT THE 24-HOUR FORECAST TIME...ENDING NEAR 19N60W AT
THE 48-HOUR FORECAST TIME. THE GFS MODEL FORECAST FOR 700 MB
SHOWS THAT A NORTHEAST-TO-SOUTHWEST ORIENTED RIDGE WILL EXTEND
FROM AN ATLANTIC OCEAN 23N59W TO HISPANIOLA AND JAMAICA.

...THE ATLANTIC OCEAN...

A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N49W TO
24N48W. THE TROUGH SUPPORTS A COLD FRONT THAT PASSES THROUGH
32N48W TO 28N55W AND 26N61W. THE COLD FRONT IS DISSIPATING FROM
26N61W TO 26N69W. A PRE-FRONTAL SURFACE TROUGH IS ALONG 31N47W
TO 26N49W AND 22N53W.SURFACE ANTICYCLONIC WIND FLOW COVERS THE
ATLANTIC OCEAN TO THE NORTH AND NORTHWEST OF THE COLD FRONT. A
1022 MB HIGH PRESSURE CENTER IS NEAR 32N62W. CONVECTIVE
PRECIPITATION...NUMEROUS STRONG WITHIN 30 NM TO 60 NM ON EITHER
SIDE OF 32N42W 30N43W 24N47W. BROKEN TO OVERCAST MULTILAYERED
CLOUDS AND POSSIBLE RAINSHOWERS ARE ELSEWHERE FROM 22N NORTHWARD
BETWEEN 39W AND 60W.

A SURFACE RIDGE PASSES THROUGH 32N29W TO 27N33W TO 20N40W.
SURFACE ANTICYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN FROM
10N NORTHWARD BETWEEN AFRICA AND THE 31N47W TO 22N53W PRE-
FRONTAL SURFACE TROUGH.

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

$$
MT



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