[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211145
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT MON OCT 21 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
1015 UTC.

...SPECIAL FEATURE...

A 1012 MB LOW PRESSURE CENTER IS NEAR 27N56W. CONVECTIVE
PRECIPITATION...NUMEROUS STRONG FROM 25N TO 30N BETWEEN 53W AND
56W. THE CONVECTIVE PRECIPITATION THAT ACCOMPANIES THIS FEATURE
HAS INCREASED AND IT HAS BECOME BETTER ORGANIZED DURING THE LAST
FEW HOURS. THIS LOW CENTER HAS THE POTENTIAL TO BECOME A SHORT-
LIVED TROPICAL CYCLONE LATER TODAY OR TUESDAY BEFORE THE UPPER
LEVEL WINDS BECOME UNFAVORABLE FOR DEVELOPMENT. THIS SYSTEM HAS
A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48
HOURS. THIS SYSTEM IS FORECAST TO MOVE NORTH-NORTHEAST...AND
THEN TO THE EAST-NORTHEAST.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 37W TO THE SOUTH OF 14N
MOVING WESTWARD 10 TO 15 KNOTS. CONVECTIVE PRECIPITATION...
WIDELY SCATTERED TO SCATTERED MODERATE TO ISOLATED STRONG FROM
6N TO 14N BETWEEN 32W AND 40W. PART OF THE PRECIPITATION IS
RELATED TO THE ITCZ ALSO.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 67W/68W TO THE SOUTH OF
PUERTO RICO MOVING WESTWARD 5 TO 10 KNOTS. THE WAVE SPEED HAS
SLOWED DOWN AS IT MOVES INTO THE AREA OF A PERSISTENT MIDDLE
LEVEL TO UPPER LEVEL TROUGH THAT RUNS FROM THE ATLANTIC
OCEAN...THROUGH THE MONA PASSAGE...INTO THE CARIBBEAN SEA.
CONVECTIVE PRECIPITATION...IT IS NOT EASY TO FIND PRECIPITATION
THAT ONLY IS RELATED TO THE TROPICAL WAVE...DUE TO THE PRESENCE
OF THE TROUGH.

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

THE MONSOON TROUGH PASSES THROUGH COASTAL MAURITANIA NEAR 17N16W
TO 10N21W. THE ITCZ CONTINUES FROM 10N21W TO 6N26W 5N34W...TO
6N43W. CONVECTIVE PRECIPITATION...WIDELY SCATTERED TO SCATTERED
MODERATE TO ISOLATED STRONG FROM 3N TO 11N BETWEEN 18W AND 60W.

...DISCUSSION...

FROM THE ATLANTIC OCEAN...ACROSS HISPANIOLA...INTO THE
CARIBBEAN SEA...

A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS IN
THE ATLANTIC OCEAN NEAR 22N66W. A TROUGH EXTENDS FROM THE
CYCLONIC CENTER TO THE MONA PASSAGE...TO 14N70W IN THE CARIBBEAN
SEA. A TROUGH EXTENDS NORTHEASTWARD FROM THE CYCLONIC CENTER TO
27N64W AND 29N62W. COMPARATIVELY DRIER AIR IN SUBSIDENCE...AS
SEEN IN WATER VAPOR IMAGERY...COVERS HISPANIOLA AND ITS COASTAL
WATERS. CONVECTIVE PRECIPITATION...SCATTERED STRONG FROM 18N TO
22N BETWEEN 60W AND 64W. ISOLATED MODERATE IN THE CARIBBEAN SEA
ELSEWHERE TO THE SOUTH OF 19N BETWEEN 60W AND 70W. WIDELY
SCATTERED MODERATE TO ISOLATED STRONG ELSEWHERE IN THE ATLANTIC
OCEAN FROM 20N TO 25N BETWEEN 55W AND 67W.

THE GFS FORECAST FOR 700 MB SHOWS THAT ANTICYCLONIC WIND FLOW...
WILL COVER THE AREA FOR AT LEAST THE FIRST HALF OF THE FIRST 24
HOURS OF THE FORECAST PERIOD. AN INVERTED TROUGH AND/OR CYCLONIC
WIND FLOW FROM AN INVERTED TROUGH...WILL COVER THE AREA FOR THE
REST OF THE 48 HOUR FORECAST PERIOD. THE GFS FORECASTS FOR 500
MB AND FOR 250 MB SHOW THAT HISPANIOLA WILL BE ON THE WESTERN
SIDE OF A TROUGH FOR THE FIRST 36 HOURS OR MORE OF THE 48 HOUR
FORECAST PERIOD. THE CYCLONIC CENTER THAT IS ASSOCIATED WITH THE
TROUGH EVENTUALLY WILL MOVE TOWARD THE NORTHERN/NORTHWESTERN
SECTIONS OF THE DOMINICAN REPUBLIC.

FROM THE GULF OF MEXICO...INTO THE ATLANTIC OCEAN...AND
INCLUDING IN THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA...

A MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC CYCLONIC CIRCULATION
CENTER IS IN THE BAHAMAS NEAR 24N76W. ANTICYCLONIC WIND FLOW
COVERS THE GULF OF MEXICO...THE ATLANTIC OCEAN THAT IS TO THE
WEST OF THE CYCLONIC WIND FLOW THAT IS MOVING AROUND THE 22N66W
CYCLONIC CIRCULATION CENTER...AND THE CARIBBEAN SEA TO THE NORTH
OF 16N TO THE WEST OF 80W. COMPARATIVELY DRIER AIR IN
SUBSIDENCE...AS SEEN IN WATER VAPOR IMAGERY...COVERS THE
NORTHWESTERN CORNER OF THE CARIBBEAN SEA...THE ATLANTIC OCEAN TO
THE SOUTH OF 30N TO THE WEST OF 70W...AND THE GULF OF MEXICO TO
THE SOUTHEAST OF 28N83W 26N88W 22N90W. A STATIONARY FRONT PASSES
THROUGH THE ATLANTIC OCEAN NEAR 32N75W...TO FLORIDA NEAR
28N82W...TO THE CENTRAL GULF OF MEXICO NEAR 25N90W. A WARM FRONT
CONTINUES FROM 25N90W TO 23N96W. CONVECTIVE PRECIPITATION...
SCATTERED MODERATE TO ISOLATED STRONG IN THE COASTAL WATERS OF
MEXICO AND TEXAS FROM 23N TO 27N TO THE WEST OF 93W. WIDELY
SCATTERED MODERATE TO ISOLATED STRONG IN THE GULF WATERS TO THE
SOUTH OF 22N BETWEEN THE YUCATAN PENINSULA AND 94W. BROKEN TO
OVERCAST MULTILAYERED CLOUDS ARE TO THE WEST/NORTHWEST OF THE
LINE THAT PASSES THROUGH APALACHEE BAY FLORIDA TO 25N90W
AND 22N90W.

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

LOW CLOUD CEILINGS AND SOME MIDDLE LEVEL CLOUD CEILINGS COVER
THE FOLLOWING ICAO STATIONS...KMZG...KBBF...KGUL...KBQX...
KVAF...KEMK...KHQI...KIPN...KMDJ...KDLP...AND KVBS. FAIR
SKIES/CLEAR SKIES AT OR LOWER THAN 12000 FEET ARE BEING REPORTED
ELSEWHERE ACROSS THE AREA.

PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE
OFFSHORE FORECAST...MIAOFFNT4...FOR MORE DETAILS ABOUT THE 36-
HOUR FORECAST COLD FRONT 30N85W 23N96W 19N96W. EXPECT NORTH
WINDS 20 TO 25 KNOTS AND SEA HEIGHTS LOWER THAN 8 FEET TO THE
SOUTH OF 26N TO THE WEST OF THE FRONT.

THE REST OF THE CARIBBEAN SEA...

THE 24-HOUR RAINFALL TOTAL IN INCHES FOR THE PERIOD ENDING AT
21/0000 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN...IS 0.34 IN GUADELOUPE.

THE MONSOON TROUGH IS ALONG 9N75W IN COLOMBIA...THROUGH WESTERN
PANAMA AND SOUTHERN COSTA RICA...BEYOND 9N84W INTO THE EASTERN
PACIFIC OCEAN. CONVECTIVE PRECIPITATION...NUMEROUS STRONG IN
COLOMBIA AND COASTAL WATERS FROM 8N TO 11N BETWEEN 75W AT THE
COAST AND 78W...IN THE COLOMBIA COASTAL WATERS FROM 4N TO 7N TO
THE EAST OF 80W...AND IN AND NEAR THE WESTERN PART OF LAKE
MARACAIBO IN VENEZUELA. WIDELY SCATTERED MODERATE TO ISOLATED
STRONG ELSEWHERE IN THE SOUTHWESTERN CORNER OF THE CARIBBEAN SEA
TO THE SOUTH OF 16N TO THE WEST OF 75W.

THE REST OF THE ATLANTIC OCEAN...

A FAR EASTERN ATLANTIC OCEAN MIDDLE LEVEL TO UPPER LEVEL
TROUGH/SHEAR AXIS PASSES THROUGH 32N15W TO 25N18W 17N32W AND
14N40W. CONVECTIVE PRECIPITATION...ISOLATED MODERATE TO
LOCALLY STRONG FROM 12N TO 14N BETWEEN 38W AND 44W.

A SURFACE RIDGE PASSES THROUGH 32N12W TO 28N24W...TO A 1020 MB
HIGH PRESSURE CENTER THAT IS NEAR 27N33W...TO A 1020 MB HIGH
PRESSURE CENTER THAT IS NEAR 29N45W...BEYOND 32N47W.

PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...FOR MORE
DETAILS ABOUT THE 6 HOUR FORECAST...OF WINDS 20 KNOTS OR LESS
AND SEA HEIGHTS TO 8 FEET FROM 10N TO 13N BETWEEN 45W AND 50W.
THE 24 HOUR FORECAST CONSISTS OF A 1012 MB LOW PRESSURE CENTER
NEAR 29N55W...A POSSIBLE TROPICAL CYCLONE. WINDS 20 KNOTS OR
LESS AND SEA HEIGHTS LOWER THAN 8 FEET.

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

$$
MT


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