[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 161059
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT MON JUL 16 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.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 17N37W 11N40W 3N42W
MOVING WEST 10 TO 15 KT. ITCZ PRECIPITATION REALLY DOES NOT
APPEAR TO BE AFFECTED BY THIS WAVE. LOW CLOUDS IN THE EARLIEST
VISIBLE IMAGES ARE MOVING CYCLONICALLY AROUND THIS WAVE.

AN EASTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 20N63W 14N67W
INTO WESTERN VENEZUELA NEAR 7N69W. THIS WAVE WAS MOVED
COMPARATIVELY QUITE A BIT BECAUSE OF THE WESTWARD-TO-
SOUTHWESTWARD PUSH OF THE STRATIFORM CLOUDS IN SATELLITE
IMAGERY. THESE CLOUD MOVEMENTS SUGGEST TO ME THAT THIS WAVE
MUST BE WEST OF 60W...AND NOT STILL EAST OF 60W WHERE WE HAD
BEEN LOCATING IT. I MOVED THE NORTHERN END OF THE WAVE AT LEAST
5 DEGREES IN LONGITUDE BECAUSE OF THE STRATIFORM CLOUD FIELD
IN THE ATLANTIC OCEAN. IT IS NOT EXACTLY THAT EASY TO SEE LOW
CLOUDS MOVING CYCLONICALLY AROUND THIS WAVE BECAUSE OF ALL THE
HIGH CLOUDS TO THE EAST OF THE CARIBBEAN SEA THAT ARE VEERING
NORTHEASTWARD ACROSS THE EASTERN CARIBBEAN SEA ISLANDS.
ISOLATED MODERATE SHOWERS FROM 16N TO 20N BETWEEN 60W AND 70W.

A TROPICAL WAVE IS ALONG 93W/95W SOUTH OF 20N MOVING WEST
10 TO 15 KT...PASSING THROUGH THE ISTHMUS OF TEHUANTEPEC
IN MEXICO INTO THE EASTERN PACIFIC OCEAN. SCATTERED STRONG
SHOWERS AND THUNDERSTORMS ARE FROM 13N TO 17N BETWEEN 92W AND
100W MOSTLY IN THE COASTAL WATERS OF THE EASTERN PACIFIC OCEAN.
SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE
FROM 17N TO 20N BETWEEN 95W AND 97W INTO THE SOUTHWESTERN CORNER
OF THE GULF OF MEXICO.

...THE ITCZ...
FROM THE COAST OF AFRICA NEAR 9N13W TO 8N17W 9N30W 9N37W 7N43W
TO 5N56W IN NORTHERN SURINAME. STRONG SHOWERS AND THUNDERSTORMS
ARE FROM 5N TO 7N BETWEEN 47W AND 49W. ISOLATED MODERATE SHOWERS
FROM 5N TO 10N BETWEEN AFRICA AND 50W.

...DISCUSSION...
THE GULF OF MEXICO...
THE SURFACE PRESSURE PATTERN IS WEAK. A SURFACE RIDGE ENTERS
THE AREA FROM THE ATLANTIC OCEAN...CROSSING SOUTH FLORIDA...
INTO THE CENTRAL GULF OF MEXICO. A MIDDLE TO UPPER LEVEL TROUGH
SWINGS INTO THE AREA FROM THE UPPER TEXAS COAST TO 21N96W IN THE
SOUTHWESTERN GULF OF MEXICO. UPPER LEVEL ANTICYCLONIC FLOW RUNS
FROM THE STRAITS OF FLORIDA NORTHWARD ACROSS FLORIDA BEYOND 32N
ALONG THE SOUTHEASTERN U.S.A. COAST. WARMING CLOUD TEMPERATURES
AND WEAKENING PRECIPITATION IS IN THE NORTHEASTERN QUADRANT.
SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE
FORMING IN THE NORTHWESTERN QUADRANT OFF THE TEXAS COAST...AND
IN THE NORTH CENTRAL GULF WATERS ALONG THE LOUISIANA COAST
IN ADVANCE OF THIS TROUGH. STRONG SHOWERS AND THUNDERSTORMS ARE
IN THE MEXICO EASTERN PACIFIC WATERS WITH THE 93W/95W TROPICAL
WAVE.

THE CARIBBEAN SEA...
AN UPPER LEVEL RIDGE HAS BEEN IN THE WESTERN CARIBBEAN SEA FOR
THE LAST FEW DAYS. A MIDDLE TO UPPER LEVEL TROUGH HAS SWEPT INTO
THE AREA FROM THE ATLANTIC OCEAN...ACROSS HISPANIOLA AND CUBA...
INTO THE CENTRAL AND SOUTH CENTRAL CARIBBEAN SEA. THE RIDGE HAS
BECOME MORE PRONOUNCED...AS THE TROUGH HAS BECOME MORE AND MORE
WELL-DEFINED AND CONTINUED TO GROW TOWARD THE WEST AND SOUTHWEST
FROM ITS HUMBLE BEGINNINGS ONLY IN THE ATLANTIC OCEAN 3 DAYS AGO.
THE 20N63W 14N67W 7N69W TROPICAL WAVE IS MOVING UNDERNEATH THE
UPPER LEVEL ANTICYCLONIC FLOW ON THE EASTERN SIDE OF THE TROUGH.
MIDDLE TO HIGH LEVEL CLOUDS ARE EAST OF 20N68W 16N72W 11N77W.
ISOLATED MODERATE SHOWERS ARE NORTH OF 18N BETWEEN HAITI AND
WESTERN CUBA. THESE SHOWERS HAVE BEEN WEAKENING DURING THE LAST
FEW HOURS. STRONG SHOWERS AND THUNDERSTORMS ARE SOUTH OF 10N
BETWEEN COLOMBIA AND PANAMA...AND IN WESTERN PANAMA...IN BROAD
SURFACE LOW PRESSURE AND THE ITCZ.

THE ATLANTIC OCEAN...
A SURFACE RIDGE PASSES OVER BERMUDA TO SOUTH FLORIDA...AND
ULTIMATELY INTO THE WESTERN GULF OF MEXICO. BROAD SURFACE
ANTICYCLONIC FLOW IS NORTH OF 20N BETWEEN AFRICA AND FLORIDA.
A MIDDLE TO UPPER LEVEL TROUGH STRETCHES FROM A CYCLONIC
CIRCULATION CENTER NEAR 30N58W TO 26N66W TO A CYCLONIC
CIRCULATION CENTER IN THE WINDWARD PASSAGE...AND SOUTHWESTWARD
INTO THE CARIBBEAN SEA. ISOLATED MODERATE SHOWERS ARE FROM 20N
BEYOND 32N BETWEEN 55W AND 75W. A NARROW MIDDLE TO UPPER LEVEL
TROUGH PASSES THROUGH THE CANARY ISLANDS NEAR 29N18W TO 24N29W
18N36W TO 10N47W. ANOTHER AREA OF WEAK CYCLONIC FLOW APPEARS
TO BE NEAR 13N18W JUST OFF THE AFRICA COAST.

$$
MT




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