[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 280554
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT MON SEP 28 2009

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...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 0000 UTC SURFACE ANALYSIS AND...GOES-12 SATELLITE
IMAGERY THROUGH 0315 UTC AND METEOSAT-8 IMAGERY THROUGH
0515 UTC.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 18N31W 13N33W 8N33W
MOVING WESTWARD 10 TO 15 KT. ISOLATED MODERATE SHOWERS AND
POSSIBLE THUNDERSTORMS FROM 6N TO 15N BETWEEN 28W AND 34W.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 80W TO THE SOUTH OF 18N
MOVING WEST 10 TO 15 KT. THE WAVE IS MOVING THROUGH THE BASE
OF A MIDDLE LEVEL TO UPPER LEVEL TROUGH. THE STRONG SHOWERS
AND THUNDERSTORMS FROM COLOMBIA'S GULF OF URABA TO 12N80W
PROBABLY ARE MORE RELATED TO THE ITCZ AND THE MIDDLE LEVEL
TO UPPER LEVEL TROUGH.

...THE ITCZ...

FROM SIERRA LEONE TO 8N13W 11N26W 12N32W 8N46W TO 10N63W IN
NORTHEASTERN VENEZUELA. ISOLATED MODERATE SHOWERS AND POSSIBLE
THUNDERSTORMS COVER THE REST OF THE AREA FROM 4N TO 10N
BETWEEN AFRICA AND 50W...AND FROM 10N TO 14N BETWEEN 50W AND
60W.

...DISCUSSION...

THE GULF OF MEXICO...
CYCLONIC FLOW FROM A DEEP LAYER TROUGH COVERS THE U.S.A. TO THE
EAST OF 90W. THIS TROUGH SUPPORTS A CURRENT COLD FRONT THAT
PASSES THROUGH 32N76W TO THE FLORIDA COAST NEAR TAMPA...INTO THE
EASTERN GULF OF MEXICO NEAR 27N88W. HIGH CLOUDS ARE WITHIN 75 NM
ON EITHER SIDE OF 26N95W 28N90W 29N83W BEYOND 31N79W WITH THE
UPPER LEVEL SOUTHWESTERLY WIND FLOW. POSSIBLE SHOWERS ARE TO THE
SOUTH OF 27N TO THE EAST OF 93W. AN UPPER LEVEL CYCLONIC
CIRCULATION CENTER IS IN SOUTHEASTERN MEXICO...MOVING AWAY FROM
THE BORDER WITH GUATEMALA TOWARD THE GULF OF TEHUANTEPEC ON THE
PACIFIC OCEAN SIDE OF MEXICO. DISSIPATING PRECIPITATION IS IN
THE NORTHWESTERN CORNER OF THE YUCATAN PENINSULA. SHOWERS AND
THUNDERSTORMS ARE ON THE CARIBBEAN SEA COAST OF CUBA TO THE WEST
OF 81W...IN AN AREA OF CONFLUENT WINDS AT THE SURFACE AND UPPER
LEVEL DIFFLUENT WIND FLOW.

THE CARIBBEAN SEA...
THE SOUTHERN END OF THE DEEP LAYER ATLANTIC OCEAN TROUGH PASSES
THROUGH THE MONA PASSAGE TO 12N80W...SLICING THROUGH CENTRAL
NICARAGUA...TOWARD THE UPPER LEVEL CYCLONIC CENTER THAT IS
EXITING SOUTHWESTERN GUATEMALA AND MOVING INTO SOUTHEASTERN
MEXICO. THE STRONG SHOWERS AND THUNDERSTORMS FROM COLOMBIA'S
GULF OF URABA TO 12N80W PROBABLY ARE MORE RELATED TO THE ITCZ
AND THE MIDDLE LEVEL TO UPPER LEVEL TROUGH. ISOLATED MODERATE
SHOWERS ARE TO THE SOUTH OF 14N TO THE EAST OF 68W...RELATED
TO THE ITCZ.

THE ATLANTIC OCEAN...
CYCLONIC FLOW FROM A DEEP LAYER TROUGH COVERS THE U.S.A.
TO THE EAST OF 90W. THIS TROUGH SUPPORTS A CURRENT COLD FRONT
THAT PASSES THROUGH 32N76W TO THE FLORIDA COAST NEAR TAMPA...
INTO THE EASTERN GULF OF MEXICO NEAR 27N88W. ISOLATED MODERATE
SHOWERS IN THE ATLANTIC OCEAN ARE WITHIN 15 NM TO 30 NM ON
EITHER SIDE OF 25N80W 28N78W 30N77W. POSSIBLE SHOWERS ARE
WITHIN 30 NM ON EITHER SIDE OF THE LINE FROM THE NORTHERN
BAHAMA ISLANDS BEYOND 32N72W. A DEEP LAYER CENTRAL ATLANTIC
OCEAN TROUGH PASSES THROUGH 32N43W TO A 28N54W CYCLONIC CENTER
AND TO 24N65W...THROUGH THE MONA PASSAGE INTO THE CARIBBEAN SEA.
A COLD FRONT PASSES THROUGH 32N42W TO 29N50W. A STATIONARY FRONT
CONTINUES FROM 29N50W TO 29N55W AND 30N60W. ISOLATED MODERATE
SHOWERS AND POSSIBLE THUNDERSTORMS ARE WITHIN 200 NM TO THE
SOUTH AND SOUTHEAST OF THE TROUGH. A MIDDLE LEVEL TO UPPER LEVEL
TROUGH GOES FROM 21N39W TO 15N40W TO 11N41W. A SURFACE TROUGH
FROM 15N40W TO 23N41W IS THE REMNANT OF T.D. EIGHT. ISOLATED
MODERATE SHOWERS FROM 18N TO 20N BETWEEN 39W AND 41W. AN EASTERN
ATLANTIC OCEAN MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH
32N19W TO 26N26W TO 24N33W. NO SURFACE FRONT OR TROUGH IS
ACCOMPANIES THIS TROUGH.

$$
MT





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