[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 041112
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT THU OCT 04 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN
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...METEOROLOGICAL ANALYSIS...
WEATHER OBSERVATIONS...AND RADAR.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1045 UTC.

...SPECIAL FEATURES...

A GULF OF MEXICO 1006 MB LOW PRESSURE CENTER IS NEAR 27N88W.
THIS SYSTEM HAS A WELL-DEFINED LOW-LEVEL CIRCULATION. IT IS
POSSIBLE THAT THIS SYSTEM MAY BECOME A TROPICAL OR SUBTROPICAL
DEPRESSION DURING THE NEXT DAY OR SO AS IT MOVES GENERALLY
NORTHWESTWARD ABOUT 10 MPH. RESIDENTS ALONG THE NORTHERN GULF
OF MEXICO COAST SHOULD CONTINUE TO MONITOR THE PROGRESS OF
THIS SYSTEM. A BIG MIDDLE TO UPPER LEVEL TROUGH IS ON TOP OF
THE GULF OF MEXICO FROM THE NORTHEASTERN CORNER OF THE AREA
TO THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO...AND EVEN
PASSING OVER INTERIOR MEXICO TO THE EASTERN PACIFIC COAST...
AND EVENTUALLY INTO THE EASTERN PACIFIC OCEAN NEAR 13N100W.
ISOLATED MODERATE SHOWERS FROM 24N TO 25N BETWEEN 90W AND
93W...AND FROM 25N TO 30N BETWEEN 87W AND 89W.

A SURFACE TROUGH IS ALONG 29N70W TO 27N74W TO THE BAHAMAS NEAR
26N77W TO 24N77W. STRONG SHOWERS AND THUNDERSTORMS IN CLUSTERS
FROM THE WINDWARD PASSAGE TO 180 NM SOUTH OF JAMAICA TO THE CUBA
COASTAL WATERS NEAR 21N82W...FROM THE WESTERN DOMINICAN REPUBLIC
TO JUST NORTH OF GREAT INAGUA TO 25N BETWEEN 70W AND 74W.
UPPER LEVEL ANTICYCLONIC FLOW COVERS THE AREA FROM THE CARIBBEAN
SEA NEAR 13N TO THE ATLANTIC OCEAN NEAR 32N BETWEEN 60W AND 84W.
UPPER-LEVEL WINDS APPEAR TO BE SOMEWHAT FAVORABLE FOR
DEVELOPMENT...AND A TROPICAL DEPRESSION MAY FORM IN THIS AREA
DURING THE NEXT DAY OR TWO AS THE FEATURE MOVES SLOWLY WESTWARD
OR WEST-SOUTHWESTWARD.

A 1012 MB LOW PRESSURE CENTER IS ALONG A 44W/45W TROPICAL WAVE
THAT IS SOUTH OF 15N...AND MOVING WEST 10 TO 15 KT. SCATTERED
STRONG SHOWERS AND THUNDERSTORMS FROM 11N TO 17N BETWEEN 47W
AND 48W. ISOLATED MODERATE SHOWERS ELSEWHERE FROM 10N TO 20N
BETWEEN 40W AND 47W. UPPER-LEVEL WINDS ARE EXPECTED TO BECOME
GRADUALLY LESS FAVORABLE FOR DEVELOPMENT TO A TROPICAL CYCLONE
DURING THE NEXT DAY OR TWO.

THE REMNANTS OF TROPICAL DEPRESSION MELISSA ARE ABOUT 1000 NM
SOUTHEAST OF BERMUDA. SIGNIFICANT RE-DEVELOPMENT IS NOT EXPECTED
DUE TO STRONG UPPER-LEVEL WINDS. THIS IS A 1016 MB LOW PRESSURE
CENTER NEAR 22N50W. A NARROW MIDDLE TO UPPER LEVEL TROUGH IS TO
THE WEST ALONG 28N59W 22N57W. A DEEP LAYER LEVEL TROUGH PASSES
THROUGH 32N35W 29N46W. UPPER LEVEL SOUTHWESTERLY WIND FLOW MOVES
FROM 23N46W NORTHEASTWARD. UPPER LEVEL SOUTHERLY FLOW MOVES FROM
16N49W TOWARD THE NORTH AND NORTHEAST. ISOLATED TO WIDELY
SCATTERED MODERATE SHOWERS FROM 27N TO 30N BETWEEN 50W AND 60W.

...TROPICAL WAVES...
AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 54W/55W SOUTH OF 15N
MOVING WEST 10 TO 15 KT. NO PRECIPITATION ACCOMPANIES THIS WAVE.

...THE ITCZ...
10N13W 6N20W 7N30W 9N41W 10N46W 10N52W 10N56W 10N67W. ISOLATED
MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS SOUTH OF 10N BETWEEN
10W AND 50W.

DISCUSSION...

THE GULF OF MEXICO...THE ATLANTIC OCEAN WEST OF 60W...
AND THE NORTHWESTERN CARIBBEAN SEA...
ONE BIG MIDDLE TO UPPER LEVEL TROUGH STRETCHES FROM THE
NORTHEASTERN CORNER OF THE AREA TO THE SOUTHWESTERN
CORNER...INCLUDING ACROSS THE ISTHMUS OF TEHUANTEPEC...
INTO THE EASTERN PACIFIC COAST NEAR 13N100W. A FEW CYCLONIC
SWIRLS/CIRCULATION CENTERS ARE EMBEDDED IN THIS TROUGH.
A 1006 MB LOW PRESSURE CENTER IS NEAR 27N88W. THIS LOW
PRESSURE CENTER APPEARS ON THE TAFB DANGER GRAPHIC. IT IS
POSSIBLE THAT THIS SYSTEM MAY BECOME A TROPICAL OR SUBTROPICAL
DEPRESSION DURING THE NEXT DAY OR SO AS IT MOVES GENERALLY
NORTHWESTWARD ABOUT 10 MPH. RESIDENTS ALONG THE NORTHERN GULF
OF MEXICO COAST SHOULD CONTINUE TO MONITOR THE PROGRESS OF THIS
SYSTEM. ISOLATED MODERATE SHOWERS FROM 24N TO 25N BETWEEN 90W
AND 93W...AND FROM 25N TO 30N BETWEEN 87W AND 89W. A SURFACE
TROUGH IS ALONG 29N70W TO 27N74W TO THE BAHAMAS NEAR 26N77W TO
24N77W. STRONG SHOWERS AND THUNDERSTORMS IN CLUSTERS FROM THE
WINDWARD PASSAGE TO 180 NM SOUTH OF JAMAICA TO THE CUBA COASTAL
WATERS NEAR 21N82W...FROM THE WESTERN DOMINICAN REPUBLIC TO JUST
NORTH OF GREAT INAGUA TO 25N BETWEEN 70W AND 74W. UPPER LEVEL
ANTICYCLONIC FLOW COVERS THE AREA FROM THE CARIBBEAN SEA NEAR
13N TO THE ATLANTIC OCEAN NEAR 32N BETWEEN 60W AND 84W.
UPPER-LEVEL WINDS APPEAR TO BE SOMEWHAT FAVORABLE FOR
DEVELOPMENT...AND A TROPICAL DEPRESSION MAY FORM IN THIS AREA
DURING THE NEXT DAY OR TWO AS THE FEATURE MOVES SLOWLY WESTWARD
OR WEST-SOUTHWESTWARD.

THE CARIBBEAN SEA...
MIDDLE TO UPPER LEVEL CYCLONIC FLOW CUTS ACROSS THE YUCATAN
PENINSULA INTO A TINY PART OF THE NORTHWESTERN CORNER OF THE
AREA. THIS FLOW IS MET BY UPPER LEVEL ANTICYCLONIC FLOW TO THE
EAST OF IT...NORTH OF 13N BETWEEN 58W IN THE ATLANTIC OCEAN AND
THE NORTHEASTERN COAST OF NICARAGUA. WEAKENING MIDDLE LEVEL
CYCLONIC FLOW APPEARS TO BE DISSIPATING NEAR 10N60W. MIDDLE TO
UPPER LEVEL DRY AIR/SUBSIDENCE RESTS ACROSS VENEZUELA NORTH OF
7N...AND IN PARTS OF THE CARIBBEAN SEA SOUTH OF 15N BETWEEN 64W
AND 75W. A SURFACE TROUGH IS ALONG 29N70W TO 27N74W TO THE
BAHAMAS NEAR 26N77W TO 24N77W. STRONG SHOWERS AND THUNDERSTORMS
IN CLUSTERS FROM THE WINDWARD PASSAGE TO 180 NM SOUTH OF JAMAICA
TO THE CUBA COASTAL WATERS NEAR 21N82W...FROM THE WESTERN
DOMINICAN REPUBLIC TO JUST NORTH OF GREAT INAGUA TO 25N BETWEEN
70W AND 74W. UPPER LEVEL ANTICYCLONIC FLOW COVERS THE AREA FROM
THE CARIBBEAN SEA NEAR 13N TO THE ATLANTIC OCEAN NEAR 32N
BETWEEN 60W AND 84W. UPPER-LEVEL WINDS APPEAR TO BE SOMEWHAT
FAVORABLE FOR DEVELOPMENT...AND A TROPICAL DEPRESSION MAY FORM
IN THIS AREA DURING THE NEXT DAY OR TWO AS THE FEATURE MOVES
SLOWLY WESTWARD OR WEST-SOUTHWESTWARD. ISOLATED MODERATE SHOWERS
FROM 18N TO 19N BETWEEN 57W AND 59W ARE RELATED TO A MIDDLE TO
UPPER LEVEL TROUGH THAT IS JUST TO THE EAST OF THE AREA. A WEAK
SURFACE TROUGH APPEARS TO BE IN THE NORTHEASTERN CORNER OF THE
AREA. EXPECT THIS FEATURE TO BE ADDED TO THE SURFACE MAP
ANALYSIS OF 04/1200 UTC.

THE REST OF THE ATLANTIC OCEAN EAST OF 60W...
A DEEP LAYER TROUGH GOES PASSES THROUGH 32N35W TO 29N46W. THIS
TROUGH SUPPORTS THE COLD FRONT THAT PASSES THROUGH 32N30W TO
27N40W TO 27N47W. ISOLATED TO WIDELY SCATTERED MODERATE SHOWERS
FROM 26N TO 1N BETWEEN 25W AND 33W. STRONG SHOWERS AND
THUNDERSTORMS FROM 22N TO 25N BETWEEN 47W AND 50W NEAR THE
REMNANT LOW OF MELISSA. DEEP LAYER CYCLONIC FLOW COVERS
SPAIN/PORTUGAL/THE NORTHERN HALF OF MOROCCO. AN UPPER LEVEL
RIDGE IS ALONG 17N41W 23N36W 26N31W BEYOND 32N26W.

$$
MT


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