Tropical Weather Discussion
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000
AXNT20 KNHC 050605
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT SEP 05 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...SPECIAL FEATURES...

TROPICAL STORM FRED HAS REGAINED SOME STRENGTH...AND IT HAS
INTENSIFIED FROM A TROPICAL DEPRESSION. THE CENTER OF TROPICAL
STORM FRED AT 05/0300 UTC IS NEAR 22.8N 40.1W. FRED IS MOVING
TOWARD THE WEST-NORTHWEST...OR 290 DEGREES...09 KNOTS. THE
MINIMUM CENTRAL PRESSURE IS 1009 MB. THE MAXIMUM SUSTAINED WIND
SPEEDS ARE 35 KNOTS WITH GUSTS TO 45 KNOTS. PUBLIC ADVISORIES
ABOUT TROPICAL STORM FRED ARE BEING ISSUED UNDER THE WMO HEADER
WTNT31 KNHC...AND UNDER THE AWIPS HEADER MIATCPAT1.
FORECAST/ADVISORIES ABOUT TROPICAL STORM FRED ARE BEING ISSUED
UNDER THE WMO HEADER WTNT21 KNHC...AND UNDER THE AWIPS HEADER
MIATCMAT1. CONVECTIVE PRECIPITATION...ONE EARLIER AREA OF
SCATTERED TO NUMEROUS STRONG DEVELOPED AND LASTED FOR A FEW
HOURS WITHIN A RADIUS OF 60 NM OF 23N38W. THAT AREA HAS WEAKENED
AND DISSIPATED SINCE THEN. SCATTERED MODERATE TO ISOLATED STRONG
HAS DEVELOPED RECENTLY WITHIN A 60 NM RADIUS OF 23N39W.

A TROPICAL WAVE IS ALONG 21W/22W FROM 19N SOUTHWARD. A 1009 MB
LOW PRESSURE CENTER IS ALONG THE WAVE NEAR 11N. THIS SYSTEM
CONTINUES TO SHOW SIGNS OF ORGANIZATION. IT IS LIKELY THAT A
TROPICAL DEPRESSION MAY FORM DURING THE NEXT COUPLE OF DAYS. THE
CHANCE FOR SUCH DEVELOPMENT IS HIGH...AS THE WAVE MOVES WESTWARD
15 TO 20 KNOTS. CONVECTIVE PRECIPITATION...SCATTERED STRONG IN A
FEW CLUSTERS FROM 11N TO 14N BETWEEN 22W AND 24W...AND FROM 11N
TO 13N BETWEEN 25W AND 26W. ISOLATED MODERATE TO LOCALLY STRONG
ELSEWHERE FROM 08N TO 14N BETWEEN 20W AND 27W.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 30W/31W FROM 18N
SOUTHWARD...MOVING WESTWARD 15 KNOTS. A 1010 MB LOW PRESSURE
CENTER IS NEAR 11.5N ALONG THE WAVE. CONVECTIVE PRECIPITATION...
ISOLATED MODERATE TO LOCALLY STRONG FROM 10N TO 14N BETWEEN 29W
AND 35W.

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 18N56W 13N57W 10N58W...
MOVING WESTWARD 15 TO 20 KNOTS. TPW IMAGERY SHOWS THAT THIS WAVE
IS IN A DRY ENVIRONMENT. NO SIGNIFICANT DEEP CONVECTIVE
PRECIPITATION IS PRESENT AT THIS TIME.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 65W/66W FROM 20N
SOUTHWARD. THE WAVE IS MOVING WESTWARD 15 KNOTS. THIS WAVE IS
MOVING INTO THE EASTERN PART OF AN AREA OF PRE-EXISTING MIDDLE
LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW WITH A TROUGH. A MIDDLE
LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR
20N69W...WITHIN 60 NM TO 90 NM OFF THE COAST OF THE DOMINICAN
REPUBLIC. THE TROUGH EXTENDS FROM THE 20N69W CYCLONIC CENTER TO
NORTHEASTERN COLOMBIA/NORTHWESTERN VENEZUELA. UPPER LEVEL
NORTHEASTERLY WIND FLOW IS CROSSING HISPANIOLA. THE TROPICAL
WAVE SHOULD BE REACHING HISPANIOLA DURING THE NEXT 24 HOURS OR
LESS. NO SIGNIFICANT DEEP CONVECTIVE PRECIPITATION IS PRESENT IN
THE CENTRAL CARIBBEAN SEA AT THIS TIME.

A SOUTHWESTERN GULF OF MEXICO TROPICAL WAVE IS 94W/95W FROM 18N
SOUTHWARD...ACROSS THE ISTHMUS OF TEHUANTEPEC...INTO THE EASTERN
PACIFIC OCEAN. CONVECTIVE PRECIPITATION...SCATTERED TO NUMEROUS
STRONG BETWEEN 94W AND 97W IN THE ISTHMUS OF TEHUANTEPEC OF
SOUTHERN MEXICO.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH PASSES COASTAL SECTIONS OF NORTHWESTERN
SENEGAL NEAR 16N17W TO THE 1009 MB LOW PRESSURE CENTER THAT IS
NEAR 11N22W...TO THE 1010 MB LOW PRESSURE CENTER THAT IS NEAR
ALONG THE 30W/31W TROPICAL WAVE NEAR 11.5N...TO 10N38W. THE ITCZ
CONTINUES FROM 10N38W TO 11N45W...AND TO COASTAL VENEZUELA NEAR
09N61W. CONVECTIVE PRECIPITATION...BROKEN MULTILAYERED CLOUDS
AND POSSIBLE RAINSHOWERS ARE ELSEWHERE WITHIN 330 NM ON EITHER
SIDE OF THE LINE 12N16W 09N31W 09N44W 08N58W.

...DISCUSSION...

FROM THE WESTERN ATLANTIC OCEAN INTO THE GULF OF MEXICO...
INCLUDING THE REST OF THE GULF OF MEXICO...

A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH THE ATLANTIC
OCEAN NEAR 32N72W TO 26N75W...INTO THE SOUTHEASTERN CORNER OF
THE GULF OF MEXICO NEAR 24N84W. A SURFACE TROUGH EXTENDS FROM A
1012 MB LOW PRESSURE CENTER THAT IS NEAR 29N72W...TO 28N76W...
AND NEAR THE FLORIDA COAST NEAR 27N80W. CONVECTIVE
PRECIPITATION...RAINSHOWERS ARE POSSIBLE FROM 24N NORTHWARD FROM
86W EASTWARD IN THE GULF OF MEXICO.  IN THE ATLANTIC OCEAN...
WIDELY SCATTERED MODERATE TO ISOLATED STRONG FROM 25N TO 29N
BETWEEN 70W AND 80W.

A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS
NEAR 17N89W IN BELIZE. CYCLONIC WIND FLOW COVERS THE GULF OF
MEXICO AND THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA...THE
YUCATAN PENINSULA...AND PARTS OF CENTRAL AMERICA FROM 13N AND EL
SALVADOR TO 22N BETWEEN 85W AND 93W.

A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS
NEAR 18N103W ALONG THE EASTERN PACIFIC OCEAN COAST OF MEXICO.
CYCLONIC WIND FLOW COVERS MEXICO FROM 25N SOUTHWARD.

UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE REST OF THE
AREA... THAT IS FROM 24N NORTHWARD FROM 90W WESTWARD.

THE CARIBBEAN SEA...

PLEASE REFER TO THE SECTION THAT IS ABOUT HISPANIOLA AND THE
SECTION THAT IS ABOUT TROPICAL WAVES...FOR MORE DETAILS ABOUT
THE CARIBBEAN SEA TROPICAL WAVE THAT IS ALONG 65W/66W FROM 20N
SOUTHWARD.

A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS
NEAR 17N89W IN BELIZE. CYCLONIC WIND FLOW COVERS THE GULF OF
MEXICO AND THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA...THE
YUCATAN PENINSULA...AND PARTS OF CENTRAL AMERICA FROM 13N AND EL
SALVADOR TO 22N BETWEEN 85W AND 93W. CONVECTIVE PRECIPITATION...
WIDELY SCATTERED MODERATE TO ISOLATED STRONG FROM 11N TO 20N
BETWEEN 83W AND 92W.

UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE AREA THAT IS
BETWEEN THE CYCLONIC WIND FLOW OF THE CENTRAL CARIBBEAN SEA
TROUGH AND THE CYCLONIC WIND FLOW THAT IS MOVING AROUND THE
BELIZE CYCLONIC CIRCULATION CENTER. CONVECTIVE PRECIPITATION...
SCATTERED TO NUMEROUS STRONG FROM 11N TO 14N BETWEEN 81W AND 84W.

THE 24-HOUR RAINFALL TOTALS IN INCHES FOR THE PERIOD ENDING AT
05/0000 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...ARE 0.69 IN
BERMUDA...0.51 IN TEGUCIGALPA IN HONDURAS...AND 0.11 IN
GUADELOUPE.

...HISPANIOLA...

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 65W/66W FROM 20N
SOUTHWARD. THE WAVE IS MOVING WESTWARD 15 KNOTS. THIS WAVE IS
MOVING INTO THE EASTERN PART OF AN AREA OF PRE-EXISTING MIDDLE
LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW WITH A TROUGH. A MIDDLE
LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR
20N69W...WITHIN 60 NM TO 90 NM OFF THE COAST OF THE DOMINICAN
REPUBLIC. THE TROUGH EXTENDS FROM THE 20N69W CYCLONIC CENTER TO
NORTHEASTERN COLOMBIA/NORTHWESTERN VENEZUELA. UPPER LEVEL
NORTHEASTERLY WIND FLOW IS CROSSING HISPANIOLA. THE TROPICAL
WAVE SHOULD BE REACHING HISPANIOLA DURING THE NEXT 24 HOURS OR
LESS.

CURRENT CONDITIONS...IN PORT-AU-PRINCE HAITI...THE LAST
OBSERVATION FOR 05/0000 UTC AND EARLIER OBSERVATIONS...SHOWED
SCATTERED CUMULONIMBUS CLOUDS AND SCATTERED HIGH LEVEL CLOUDS.
IN THE DOMINICAN REPUBLIC...FEW LOW LEVEL CLOUDS IN SANTO
DOMINGO...LA ROMANA...PUNTA CANA...IN SANTIAGO...AND IN PUERTO
PLATA.

THE GFS MODEL FORECAST FOR 250 MB SHOWS THAT CYCLONIC WIND FLOW
WILL CROSS HISPANIOLA FOR THE FIRST 24 HOURS. THE TROUGH WILL
MOVE EASTWARD AFTER 24 HOURS...BRINGING ANTICYCLONIC WIND FLOW
TO THE AREA FOR THE REST OF THE 48-HOUR FORECAST PERIOD. THE GFS
MODEL FORECAST FOR 500 MB SHOWS THAT CYCLONIC WIND FLOW WILL
COVER THE AREA FOR THE FIRST 24 HOURS...THANKS TO THE 20N69W
CYCLONIC CIRCULATION CENTER AND TROUGH. THE CYCLONIC CENTER AND
TROUGH WILL MOVE NORTHWARD...BEING REPLACED BY AN INVERTED
TROUGH FOR 6 TO 12 HOURS. SOUTHERLY-TO-SOUTHWESTERLY WIND FLOW
EVENTUALLY WILL COVER THE AREA FOR THE REST OF THE 48-HOUR
FORECAST PERIOD. THIS WIND FLOW WILL BE RELATED TO A NORTHEAST-
TO-SOUTHWEST ORIENTED ATLANTIC OCEAN-TO-HISPANIOLA RIDGE. THE
GFS MODEL FOR 700 MB STARTS WITH NORTHERLY WIND FLOW THAT IS
ASSOCIATED WITH A GULF OF MEXICO-TO-CUBA-TO HISPANIOLA RIDGE.
THE NORTHERLY WIND FLOW BECOMES NORTHEASTERLY WITH A SHORTER-
WAVELENGTH RIDGE THAT DEVELOPS FROM THE BAHAMAS TO SOUTHEASTERN
CUBA. THIS WIND REGIME LASTS FOR 12 HOURS OR SO. A SITUATION OF
DIFFLUENT WIND FLOW DEVELOPS AND LASTS FOR 6 HOURS OR SO...
GIVING WAY TO HISPANIOLA NEARLY BEING IN A COL AT THE 24-HOUR
POINT IN THE 48-HOUR FORECAST PERIOD. AN INVERTED TROUGH MOVES
THROUGH THE AREA FOR 6 HOURS OR SO. SOUTHEAST-TO-EAST WIND FLOW
EVENTUALLY CONTINUES FOR THE LAST 12 TO 18 HOURS OF THE FORECAST
PERIOD...ASSOCIATED WITH AN ATLANTIC OCEAN 25N RIDGE.

THE REST OF THE ATLANTIC OCEAN...

PLEASE REFER TO THE SPECIAL FEATURES SECTION FOR MORE DETAILS
ABOUT TROPICAL STORM FRED.

UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN
FROM 22N SOUTHWARD BETWEEN 30W AND 60W. THIS ANTICYCLONIC WIND
FLOW COVERS THE ATLANTIC OCEAN TO THE SOUTHWEST OF THE WIND FLOW
THAT IS MOVING AROUND TROPICAL STORM FRED.

A SURFACE TROUGH EXTENDS FROM A 1015 MB LOW PRESSURE CENTER THAT
IS NEAR 31N48W...TO 25N52W. CONVECTIVE PRECIPITATION...ISOLATED
MODERATE FROM 27N NORTHWARD BETWEEN 38W AND 48W.

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

$$
MT


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