[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 270553
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT THU SEP 27 2012

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
VALID THROUGH 0515 UTC.

...SPECIAL FEATURE...

THE CENTER OF TROPICAL STORM NADINE AT 26/0300 UTC IS NEAR
29.5N 31.4W. NADINE IS ABOUT 555 NM/1030 KM TO THE
SOUTH-SOUTHWEST OF THE AZORES. NADINE IS MOVING SOUTHWESTWARD
5 KNOTS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 993 MB.
THE MAXIMUM SUSTAINED WIND SPEEDS ARE 45 KNOTS WITH GUSTS
TO 55 KNOTS. TROPICAL STORM FORCE WINDS EXTEND AWAY FROM
THE CENTER OF NADINE AS FAR AS 110 NM IN THE NORTHEASTERN
QUADRANT...60 NM IN THE SOUTHEASTERN QUADRANT...80 NM IN
THE SOUTHWESTERN QUADRANT...AND TO 120 NM IN THE NORTHWESTERN
QUADRANT. PLEASE READ THE FORECAST/ADVISORY UNDER AWIPS/
WMO HEADERS MIATCMAT4/WTNT24 KNHC...AND THE PUBLIC ADVISORY...
MIATCPAT4/WTNT34 KNHC...FOR MORE DETAILS. CONVECTIVE
PRECIPITATION...SCATTERED STRONG FROM 29N TO 30N BETWEEN
29W AND 31W.

...TROPICAL WAVE...

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 20N71W IN HISPANIOLA...
TO 16N74W...TO 11N75W IN THE COLOMBIA COASTAL WATERS. THE WAVE
IS MOVING WESTWARD 15 KNOTS DURING THE LAST 24 HOURS. THE
TROPICAL WAVE IS JUST TO THE EAST OF AN UPPER LEVEL TROUGH
THAT PASSES THROUGH...CENTRAL HISPANIOLA TO A 13N75W CYCLONIC
CIRCULATION CENTER TO THE GULF OF URABA OF COLOMBIA.
RAINSHOWERS ARE POSSIBLE WITHIN 60 NM ON EITHER SIDE OF THE
TROPICAL WAVE. IT IS NOT EASY TO FIND PRECIPITATION THAT
ONLY ACCOMPANIES THE WAVE.

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

THE MONSOON TROUGH PASSES THROUGH COASTAL SENEGAL NEAR 15N17W
TO 14N20W 10N28W 7N35W 8N38W. THE ITCZ CONTINUES FROM 8N38W
TO 9N43W AND 8N49W. CONVECTIVE PRECIPITATION...BROKEN TO
OVERCAST MULTILAYERED CLOUDS AND WIDELY SCATTERED MODERATE
TO ISOLATED STRONG TO THE SOUTH OF 18N TO THE EAST OF 45W.

...DISCUSSION...

THE GULF OF MEXICO...

BROAD AND LARGE-SCALE UPPER LEVEL ANTICYCLONIC WIND FLOW
MOVES ACROSS MEXICO...FROM THE EASTERN PACIFIC OCEAN AND
TROPICAL STORM NADINE...INTO THE WESTERN HALF OF THE GULF
OF MEXICO. THE ANTICYCLONIC WIND FLOW IS PUSHING HIGH LEVEL
MOISTURE ACROSS MEXICO...INTO THE GULF OF MEXICO TO THE WEST
OF 90W.

THE REMAINS OF A MIDDLE LEVEL TO UPPER LEVEL TROUGH ARE
MOVING THROUGH THE EASTERN SECTION OF THE AREA. BROKEN
TO OVERCAST MULTILAYERED CLOUDS AND ISOLATED MODERATE
CONVECTIVE PRECIPITATION ARE TO THE SOUTH OF 28N TO THE
EAST OF 90W. THE FRONTAL BOUNDARY THAT WAS CUTTING ACROSS
THE BAHAMAS INTO THE FLORIDA STRAITS HAS WEAKENED AND
DISSIPATED.

A SURFACE RIDGE EXTENDS FROM A 1022 MB NORTHERN SOUTH CAROLINA
HIGH PRESSURE CENTER...ACROSS THE FLORIDA BIG BEND...TO 27N94W
IN THE NORTHWESTERN CORNER OF THE AREA...TO COASTAL MEXICO
NEAR 22N99W.

THE CARIBBEAN SEA...

AN UPPER LEVEL TROUGH PASSES THROUGH...CENTRAL HISPANIOLA
TO A 13N75W CYCLONIC CIRCULATION CENTER TO THE GULF OF URABA
OF COLOMBIA. A TROPICAL WAVE IS JUST TO THE EAST OF THE UPPER
LEVEL SYSTEM...ALONG 20N71W IN HISPANIOLA...TO 16N74W...
TO 11N75W IN THE COLOMBIA COASTAL WATERS. BROKEN TO OVERCAST
MULTILAYERED CLOUDS AND ISOLATED MODERATE CONVECTIVE
PRECIPITATION COVER THE CARIBBEAN SEA AND THE SOUTHERN BAHAMAS
FROM THE COLOMBIA COASTAL WATERS TO 23N IN THE ATLANTIC OCEAN
BETWEEN 68W AND 79W.

THE SOUTHERN END OF AN UPPER LEVEL TROUGH PASSES THROUGH THE
YUCATAN CHANNEL...INTO THE NORTHWESTERN CORNER OF THE AREA.
SCATTERED MODERATE TO ISOLATED STRONG CONVECTIVE PRECIPITATION
IS WITHIN 30 TO 60 NM ON EITHER SIDE OF 13N82W...16N85W ALONG
THE HONDURAS COAST...TO 18N88W ALONG THE SOUTHEASTERN COAST OF
THE YUCATAN PENINSULA. THE PRECIPITATION ALSO IS TAKING PLACE
IN AN AREA OF UPPER LEVEL DIFFLUENT WIND FLOW BETWEEN THE
13N75W CYCLONIC CENTER AND THE TROUGH.

THE MONSOON TROUGH IS ALONG 8N78W ALONG THE COLOMBIA/PANAMA
BORDER...THROUGH WESTERN PANAMA...BEYOND NORTHWESTERN COSTA
RICA. CONVECTIVE  PRECIPITATION...STRONG WITHIN A 30 NM RADIUS
OF 7N74W...AND FROM 8N TO 9N BETWEEN 74W AND 76W IN COLOMBIA.

PLEASE READ THE HIGH SEAS FORECASTS...MIAHSFAT2...AND THE
OFFSHORE FORECAST...MIAOFFNT3...FOR DETAILS ABOUT 20 TO 25 KNOT
WINDS AND 8 FOOT SEA HEIGHTS FROM 12N TO 15N BETWEEN 71W AND 78W
FOR AT LEAST THE FIRST 12 HOURS OF THE FORECAST PERIOD.

THE ATLANTIC OCEAN...

A STATIONARY FRONT PASSES ON TOP OF BERMUDA...TO 29N71W...
ACROSS ELEUTHERA ISLAND AND NEW PROVIDENCE ISLAND AND ANDROS
ISLAND IN THE BAHAMAS...TO 23N82W IN THE FLORIDA STRAITS.
BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE CONVECTIVE
PRECIPITATION ARE WITHIN 120 TO 240 NM ON EITHER SIDE OF THE
LINE THAT PASSES THROUGH 34N64W TO 26N77W...TO 23N85W IN THE
SOUTHEASTERN CORNER OF THE GULF OF MEXICO.

AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 30N47W.
CYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN TO THE NORTH OF
23N BETWEEN 40W AND 57W. A SEPARATE CYCLONIC CIRCULATION CENTER
IS NEAR 23N57W. CYCLONIC WIND FLOW THAT IS MOVING AROUND THIS
CENTER COVERS THE ATLANTIC OCEAN FROM 18N TO 25N BETWEEN 50W
AND 65W. A SURFACE TROUGH IS ALONG 23N49W 19N52W. CONVECTIVE
PRECIPITATION...SCATTERED STRONG FROM 20N TO 22N BETWEEN 50W
AND 52W...SCATTERED MODERATE TO ISOLATED STRONG ELSEWHERE
FROM 20N TO 23N BETWEEN 49W AND 57W.

A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM A 25N34W
CYCLONIC CIRCULATION CENTER TO 24N47W...TO A 20N55W CYCLONIC
CIRCULATION CENTER...WESTWARD TO THE MONA PASSAGE THAT IS
BETWEEN PUERTO RICO AND HISPANIOLA. COMPARATIVELY DRIER AIR
IN SUBSIDENCE IS TO BETWEEN THE 20N55W CYCLONIC CENTER AND
THE MONA PASSAGE FROM 15N TO 24N. CONVECTIVE PRECIPITATION...
SCATTERED MODERATE TO ISOLATED STRONG FROM 19N TO 22N BETWEEN
49W AND 57W...ISOLATED MODERATE FROM 14N TO 18N BETWEEN 50W
AND 57W. ONE SURFACE TROUGH IS ALONG 23N51W 18N56W...AND
A SECOND SURFACE TROUGH IS ALONG 17N53W 14N57W.

A SURFACE RIDGE IS ALONG 27N21W 22N31W...TO A 1018 MB HIGH
PRESSURE CENTER THAT IS NEAR 22N37W. SURFACE ANTICYCLONIC WIND
FLOW COVERS THE ATLANTIC OCEAN FROM 15N TO 30N BETWEEN 20W AND
50W...EXCEPT FOR THE INFLUENCE OF TROPICAL STORM NADINE.
A SECOND SURFACE RIDGE PASSES THROUGH 34N55W TO 28N60W
AND 20N63W.

PLEASE READ THE HIGH SEAS FORECASTS...MIAHSFAT2...
FOR DETAILS ABOUT TROPICAL STORM NADINE.

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

$$
MT








This weather bulletin was brought to you by:
www.nashvilleweather.net