[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 071811
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI SEP 07 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1745 UTC.

...SPECIAL FEATURE...
A 1012 MB LOW PRESSURE CENTER WAS NEAR 29N70W. A TROUGH EXTENDS
FROM THE LOW CENTER TO 28N70W 25N74W. THIS POSITION IS ABOUT
340 NM SOUTHWEST OF BERMUDA...AND ABOUT 560 NM EAST OF DAYTONA
BEACH FLORIDA. THE 24-HOUR FORECAST IS FOR THIS LOW CENTER TO
MOVE WEST-NORTHWESTWARD NEAR 30N76W. AN UPPER LEVEL TROUGH IS
TOP OF THE AREA OF THE LOW CENTER/TROUGH. MIDDLE TO UPPER LEVEL
DRY AIR IS WEST AND NORTHWEST OF 31N74W 28N74W 26N76W...REACHING
THE NORTHERN BAHAMAS. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS
ARE FROM 29N TO 30N BETWEEN 68W AND 69W...FROM 29N TO 31N
BETWEEN 69W AND 70W...AND FROM 30N TO 31N BETWEEN 72W AND 73W.
SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE
FROM 27N TO 31N BETWEEN 63W AND 67W. SCATTERED MODERATE SHOWERS
TO ISOLATED STRONG THUNDERSTORMS NEAR AND TO THE SOUTHWEST OF
THE TROUGH GO FROM 22N TO 26N BETWEEN 72W AND 78W ACROSS THE
BAHAMAS. THE THUNDERSTORM ACTIVITY HAS BECOME MORE CONCENTRATED
THIS MORNING. UPPER LEVEL WINDS ARE BECOMING INCREASINGLY
FAVORABLE FOR ADDITIONAL DEVELOPMENT...AND A TROPICAL DEPRESSION
OR TROPICAL STORM MAY FORM LATER TODAY. AN AIR FORCE RESERVE
HURRICANE HUNTER AIRCRAFT IS SCHEDULED TO INVESTIGATE THIS
SYSTEM THIS AFTERNOON. THE LOW PRESSURE CENTER IS FORECAST TO
MOVE GENERALLY WESTWARD OR NORTHWESTWARD DURING THE NEXT COUPLE
OF DAYS. RESIDENTS ALONG THE EAST COAST OF THE UNITED STATES
SHOULD MONITOR THE PROGRESS OF THIS SYSTEM CLOSELY.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 22W S OF 19N MOVING
WEST 10 TO 15 KT. BROKEN MULTILAYERED CLOUDS COVER THE ATLANTIC
OCEAN FROM 10N TO 20N BETWEEN AFRICA AND 28W. ISOLATED MODERATE
SHOWERS ARE FROM 10N TO 13N BETWEEN 20W AND 25W. UPPER LEVEL
ANTICYCLONIC FLOW IS ON TOP OF THE AREA OF THE WAVE...WITH
WEAK MIDDLE TO UPPER LEVEL CYCLONIC FLOW IN SOME DRY AIR FROM
10N TO 20N BETWEEN 30W AND 36W.

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 48W/49W SOUTH OF 24N
MOVING WEST 10 TO 15 KT. ISOLATED MODERATE SHOWERS...ALTERNATELY
DEVELOPING AND THEN DISSIPATING WITH TIME...FROM 15N TO 20N
BETWEEN 47W AND 54W. A 1014 MB LOW PRESSURE CENTER IS NEAR
13N44W...SCATTERED MODERATE SHOWERS AND THUNDERSTORMS FROM
12N TO 13N BETWEEN 46W AND 48W.

TROPICAL WAVE IS ALONG 80W/81W SOUTH OF 19N MOVING WEST 10
TO 15 KT. UPPER LEVEL DIFFLUENT FLOW IS ALONG THE LINE FROM
NORTHEASTERN NICARAGUA TO NORTHWESTERN JAMAICA. ANOTHER AREA
OF UPPER LEVEL DIFFLUENT FLOW IS IN THE SOUTHWESTERN CORNER OF
THE CARIBBEAN SEA. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG
THUNDERSTORMS OVER THE CARIBBEAN SEA WATERS SOUTH OF 11N BETWEEN
77W AND 80W. ISOLATED MODERATE SHOWERS FROM 12N TO 15N BETWEEN
81W AND 84W FROM THE COASTAL WATERS TO EXTREME EASTERN HONDURAS
AND THE NORTHEASTERN PART OF NICARAGUA. NUMEROUS STRONG SHOWERS
AND THUNDERSTORMS ARE IN THE EASTERN PACIFIC OCEAN WEST OF
COLOMBIA FROM 4N TO 7N BETWEEN 79W AND 81W.

...THE ITCZ...
11N15W 7N24W 6N32W 8N45W 9N50W 8N62W. SCATTERED MODERATE SHOWERS
TO ISOLATED STRONG THUNDERSTORMS FROM 4N TO 9N BETWEEN 16W AND
31W. ISOLATED MODERATE SHOWERS TO LOCALLY STRONG THUNDERSTORMS
FROM 2N TO 11N BETWEEN 31W AND 47W.

DISCUSSION...

THE GULF OF MEXICO...
UPPER LEVEL ANTICYCLONIC FLOW MOVES FROM NORTH TO SOUTH ACROSS
LOUISIANA. SOME OF THIS FLOW EVENTUALLY REACHES THE NORTHWESTERN
GULF OF MEXICO COASTAL WATERS TO THE DEEP SOUTH OF TEXAS/EXTREME
NORTHEASTERN MEXICO. A MIDDLE TO UPPER LEVEL TROUGH GOES FROM
THE FLORIDA BIG BEND NORTHWARD BEYOND EASTERN ALABAMA/WESTERN
GEORGIA. SOME OF THE MIDDLE TO UPPER LEVEL CYCLONIC FLOW ALONG
THE WESTERN EDGE OF THE WESTERN ATLANTIC OCEAN TROUGH COVERS
PARTS OF THE FLORIDA...AND POSSIBLY IT HAS REACHED THE EXTREME
EASTERN GULF OF MEXICO WATERS. AN UPPER LEVEL ANTICYCLONIC
CIRCULATION CENTER IS ON TOP OF THE AREA OF THE 18.5N96W REMNANT
LOW PRESSURE CENTER OF FELIX IN MEXICO. SCATTERED MODERATE TO
STRONG SHOWERS AND THUNDERSTORMS ARE IN THE EASTERN GULF OF
MEXICO WITHIN 90 TO 150 NM ON EITHER SIDE OF 23N84W 26N86W
29N89W.

THE CARIBBEAN SEA...
SOME SHOWERS AND THUNDERSTORMS ARE WITH THE 80W/81W TROPICAL
WAVE. A MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS
ALONG THE NORTHERN BORDER OF HAITI AND THE DOMINICAN REPUBLIC.
A TROUGH EXTENDS FROM THAT CYCLONIC CENTER TO THE NORTHEASTERN
CORNER OF NICARAGUA. UPPER LEVEL ANTICYCLONIC FLOW MOVES INTO
THE NORTHWESTERN CORNER OF THE AREA NORTHWEST OF THE TROUGH.
BROAD CYCLONIC FLOW...SURROUNDED BY MIDDLE TO UPPER LEVEL DRY
AIR...IS MOVING INTO THE EASTERN CARIBBEAN SEA NOW EAST OF 66W.
SOME OF THE UPPER LEVEL FLOW IN COLOMBIA NORTH OF 5N IS CURVING
CYCLONICALLY TOWARD THE EASTERN PACIFIC OCEAN...WHILE ANOTHER
BRANCH OF UPPER LEVEL CYCLONIC FLOW CURVES NORTHEASTWARD ACROSS
THE GUAJIRA PENINSULA INTO THE SOUTHERN CARIBBEAN SEA.

THE ATLANTIC OCEAN...
MIDDLE TO UPPER LEVEL TROUGHS ABOUND. ONE TROUGH IS ON TOP OF
THE AREA OF THE 1012 MB SURFACE LOW NEAR 29N70W WITH ITS TROUGH.
A MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS ALONG THE
NORTHERN BORDER OF HAITI/THE DOMINICAN REPUBLIC. ANOTHER MIDDLE
TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 14N58W.
CYCLONIC FLOW AROUND THIS CENTER COVERS THE ATLANTIC OCEAN AND
THE CARIBBEAN SEA FROM 10N TO 20N BETWEEN 58W AND 66W. A SEPARATE
MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 15N51W
JUST WEST OF THE 48W/49W TROPICAL WAVE. BROAD UPPER LEVEL
ANTICYCLONIC FLOW IS NORTH OF 20N BETWEEN 30W AND AN APPROACHING
DEEP LAYER TROUGH THAT STILL IS JUST NORTH OF 30N. A 1022 MB
ATLANTIC OCEAN HIGH PRESSURE CENTER IS NEAR 27N34W. A RIDGE
EXTENDS FROM THIS HIGH CENTER TO A 1019 MB HIGH PRESSURE CENTER
NEAR 27N60W. AN EASTERN ATLANTIC OCEAN MIDDLE TO UPPER LEVEL
TROUGH IS MOVING ACROSS THE CANARY ISLANDS.

$$
MT

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