[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 131819
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT WED SEP 13 2006

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN
SECTIONS OF SOUTH AMERICA...AND THE 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1745 UTC.

...SPECIAL FEATURES...
THE CENTER OF HURRICANE GORDON AT 13/1500 UTC WAS NEAR
26.0N 57.9W. GORDON IS MOVING NORTH 8 KT. THE ESTIMATED
MINIMUM CENTRAL PRESSURE IS 977 MB. THE MAXIMUM SUSTAINED WIND
SPEEDS ARE 80 KT WITH GUSTS TO 100 KT. PLEASE READ THE LATEST
NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22
KNHC AND THE PUBLIC ADVISORY MIATCPAT2/WTNT32 KNHC FOR MORE
DETAILS. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE WITHIN
130 NM OF THE CENTER IN THE SOUTHERN SEMICIRCLE. THE SOUTHERN
END OF A STATIONARY FRONT REACHES 31N61W...ABOUT 330 NM TO THE
NORTH-NORTHWEST OF THE CENTER. A MIDDLE TO UPPER LEVEL LOW
PRESSURE CENTER IS NEAR 32N45W...ABOUT 760 NM TO THE EAST-
NORTHEAST OF THE CENTER OF GORDON. A MIDDLE TO UPPER LEVEL
TROUGH GOES FROM THIS LOW CENTER TO 20N50W. CYCLONIC FLOW
STRETCHES FOR ABOUT 300 NM ON EITHER SIDE OF THE TROUGH...
AND/OR THE DIAMETER AROUND THE 32N45W LOW CENTER.

THE CENTER OF TROPICAL DEPRESSION EIGHT AT 13/1500 UTC WAS
NEAR 12.0N 28.5W. THE DEPRESSION IS MOVING WEST 15 KT.
THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1007 MB. THE MAXIMUM
SUSTAINED WIND SPEEDS ARE 30 KT WITH GUSTS TO 40 KT. PLEASE
READ THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT3/WTNT23 KNHC AND THE PUBLIC ADVISORY MIATCPAT3/WTNT33
KNHC FOR MORE DETAILS. AN UPPER LEVEL RIDGE IS ALONG 20N38W
25N35W 29N33W BEYOND 32N32W CURVING THROUGH 33N28W AND 32N19W.
SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE
WITHIN 240 TO 320 NM OF THE CENTER IN THE WESTERN SEMICIRCLE.
ISOLATED MODERATE SHOWERS ARE WITHIN 300 NM OF THE CENTER
IN THE EASTERN SEMICIRCLE.

...TROPICAL WAVES...

ONE ATLANTIC OCEAN TROPICAL WAVE IS ALONG 42W/43W SOUTH OF 13N
MOVING WEST 10 TO 15 KT. ISOLATED MODERATE SHOWERS AND POSSIBLE
THUNDERSTORMS FROM 5N TO 8N BETWEEN 45W AND 48W. THE SMALL
AMOUNT OF CYCLONIC TURNING IN THE LOW TO MIDDLE LEVELS OF THE
ATMOSPHERE REMAINS...WEAKENING WITH TIME.

A SECOND ATLANTIC OCEAN TROPICAL WAVE IS ALONG 51W SOUTH OF 14N
MOVING WEST 10 TO 15 KT. THIS WAVE HAS BEEN CHALLENGING TO TRACK
AS IT CONTINUES TO BE A LOW AMPLITUDE FEATURE. THIS FEATURE
IS BARELY IDENTIFIABLE ON SATELLITE IMAGERY...SURFACE
OBSERVATION...AND QUIKSCAT DATA. ISOLATED MODERATE SHOWERS
FROM 10N TO 14N BETWEEN 50W AND 54W.

A THIRD ATLANTIC OCEAN TROPICAL WAVE IS ALONG 58W/59W SOUTH OF
18N MOVING WEST 10 TO 15 KT. THIS WAVE IS WELL-DEFINED IN THE
LOW CLOUD FIELD ON VISIBLE IMAGERY. SCATTERED STRONG SHOWERS
AND THUNDERSTORMS FROM 10N TO 18N BETWEEN 57W AND 64W.
SOME OF THIS PRECIPITATION EASILY IS REACHING THE ISLANDS
OF THE EASTERN CARIBBEAN SEA.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 70W/71W SOUTH OF 17N
MOVING WEST NEAR 15 KT. THIS WAVE IS WEAK WITH ONLY A SLIGHT
HINT OF LOW LEVEL CYCLONIC TURNING SOUTH OF 15N. A MIDDLE TO
UPPER LEVEL TROUGH RUNS FROM THE ATLANTIC OCEAN NEAR 21N70W
ACROSS HISPANIOLA INTO THE CARIBBEAN SEA NEAR 14N76W.

...THE ITCZ...
ITCZ 15N16W 14N22W 9N33W 8N41W 8N44W 8N49W 9N52W 11N57W
12N60W 10N63W. ISOLATED MODERATE SHOWERS FROM 4N TO 7N
BETWEEN 47W AND 53W.


...DISCUSSION...

THE GULF OF MEXICO...
AN UPPER LEVEL RIDGE CONTINUES FROM NORTHEASTERN MEXICO ACROSS
THE NORTHERN GULF COAST WATERS...ACROSS NORTHERN FLORIDA AND
SOUTHEASTERN GEORGIA...INTO THE ATLANTIC OCEAN. A MIDDLE TO
UPPER LEVEL TROUGH RUNS FROM A SOUTHWESTERN GULF OF MEXICO LOW
PRESSURE CENTER TO AN INTERIOR MEXICO 22N102W LOW PRESSURE
CENTER. A SURFACE COLD FRONT GOES FROM BROAD SURFACE LOW
PRESSURE IN THE WESTERN FLORIDA PANHANDLE TO THE LOWER TEXAS
COAST AND INTO NORTHERN MEXICO JUST AWAY FROM THE TEXAS BORDER.
A SECOND COLD FRONT GOES FROM SOUTHERN LOUISIANA TO CENTRAL
TEXAS. WIDELY SCATTERED MODERATE SHOWERS TO ISOLATED STRONG
THUNDERSTORMS ARE WITHIN 90 TO 120 NM NORTH OF 27N86W 27N92W
25N97W...AND FROM 27N TO 30N BETWEEN 82W AND 86W. WIDELY
SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS
ARE IN THE SOUTHWESTERN GULF WATERS AND COASTAL PLAINS SOUTH
OF 23N BETWEEN THE WESTERN YUCATAN PENINSULA AND MEXICO BETWEEN
THE COAST AND 100W.

THE CARIBBEAN SEA...
A MIDDLE TO UPPER LEVEL TROUGH RUNS FROM THE ATLANTIC OCEAN NEAR
21N70W ACROSS HISPANIOLA INTO THE CARIBBEAN SEA NEAR 14N76W.
SCATTERED STRONG SHOWERS AND THUNDERSTORMS FROM 10N TO 18N
BETWEEN 57W AND 64W ACCOMPANY THE 58W/59W TROPICAL WAVE. SOME OF
THIS PRECIPITATION EASILY IS REACHING THE ISLANDS OF THE EASTERN
CARIBBEAN SEA. THE DEEPEST MOISTURE IN THE REGION IS IN THE
EXTREME SOUTHEASTERN CORNER. WE SEE A COMBINATION OF THE
PRECIPITATION WITH THE TROPICAL WAVE AND UPPER LEVEL MOISTURE
MOVING FROM COLOMBIA AND VENEZUELA BASED ON THE ATLANTIC OCEAN-
TO-CARIBBEAN SEA TROUGH AND UPPER LEVEL ANTICYCLONIC FLOW WITH
THE ITCZ UPPER LEVEL RIDGE IN THE ATLANTIC OCEAN.

THE ATLANTIC OCEAN...
A MIDDLE TO UPPER LEVEL TROUGH GOES FROM 26N68W TO 21N70W ACROSS
HISPANIOLA IN THE CARIBBEAN SEA. ISOLATED TO WIDELY SCATTERED
MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE FROM 24N TO 29N
BETWEEN 67W AND 72W. ISOLATED MODERATE SHOWERS FROM 20N TO 25N
BETWEEN 62W AND 69W. A SURFACE TROUGH STARTS AT 31N61W AND GOES
TO AN ATLANTIC OCEAN 1015 MB LOW PRESSURE CENTER NEAR 28N66W TO
A SECOND 1015 MB LOW PRESSURE CENTER NEAR 27N72W...TO THE
BAHAMAS NEAR 23N74W AND 23N81W IN THE STRAITS OF FLORIDA.
WIDELY SCATTERED MODERATE SHOWERS TO ISOLATED STRONG
THUNDERSTORMS FROM 22N TO 24N BETWEEN 73W AND 81W. AN UPPER
LEVEL RIDGE IS ALONG 20N38W 25N35W 29N33W BEYOND 32N32W CURVING
THROUGH 33N28W AND 32N19W.

$$
MT



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