[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 291034
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT THU OCT 29 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1015 UTC.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 29W TO THE SOUTH OF 19N
MOVING WEST 10 KT. A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES
OVER THE WESTERN SAHARA TO THE CAPE VERDE ISLANDS. THE WAVE'S
WESTWARD PROGRESS IS BEING IMPEDED BY THIS TROUGH. THE WAVE HAS
NOT MOVED MUCH SINCE THE 28/0600 UTC MAP ANALYSIS. A 1010 MB LOW
PRESSURE CENTER IS ALONG THE WAVE NEAR 14N. WEAKENING
PRECIPITATION FROM 12N TO 14N BETWEEN 26W AND 28W...AND FROM
16N TO 18N BETWEEN 29W AND 31W.

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 55W TO THE SOUTH OF 16N
MOVING WEST 10 TO 15 KT. STRONG SHOWERS AND THUNDERSTORMS FROM
THE COAST OF SURINAME AND FRENCH GUIANA TO 8N BETWEEN 52W AND
55W. WEAKENING PRECIPITATION FROM 7N TO 8N BETWEEN 48W AND 52W.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 68W/69W TO THE SOUTH OF
17N MOVING WESTWARD 10 KT. SHOWERS ARE POSSIBLE WITHIN 60 NM TO
120 NM ON EITHER SIDE OF THE WAVE.

...THE ITCZ...

9N13W 7N20W 9N29W 10N32W 9N46W 9N54W INTO NORTHEASTERN VENEZUELA
NEAR 9N62W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG
THUNDERSTORMS ARE FROM 4N TO 6N BETWEEN 15W AND 18W...WEAKENING
FROM 5N TO 6N BETWEEN 25W AND 26W...FROM 7N TO 11N BETWEEN 31W
AND 50W.

...DISCUSSION...

THE GULF OF MEXICO...
UPPER LEVEL DRY AIR IN SUBSIDENCE THAT HAS BEEN PUSHED INTO THE
AREA BY THE LARGE-SCALE CARIBBEAN SEA CYCLONIC FLOW IS TO THE
SOUTH AND SOUTHEAST OF 29N83W 24N90W 20N91W. UPPER LEVEL
SOUTHWESTERLY FLOW CONTINUES ACROSS THE ENTIRE AREA. THE
SHORTWAVE
TROUGH ALONG THE TEXAS COAST FROM SIX HOURS AGO HAS LIFTED
NORTHWARD AND OVER LAND. A STATIONARY FRONT COVERS THE NORTHERN
GULF COASTAL WATERS TO THE NORTH OF 29N FROM NORTHERN FLORIDA
TO THE UPPER TEXAS COAST.

THE CARIBBEAN SEA...
BROAD LARGE-SCALE UPPER LEVEL CYCLONIC FLOW COVERS THE AREA.
THE CENTER OF THE CYCLONIC FLOW HAS MOVED TO 15N78W ABOUT 150 NM
TO THE SOUTH OF JAMAICA. THE TROUGH THAT EXTENDS TO THE EAST AND
NORTHEAST FROM THE 15N78W CYCLONIC CENTER IS ABOUT 180 NM WIDE
AS IT PASSES JUST TO THE SOUTH OF THE GREATER ANTILLES...AND
BEYOND THE NORTHEASTERN CARIBBEAN SEA ISLANDS. IT APPEARS THAT
THIS CYCLONIC CENTER MAY BECOME CUT OFF FROM THE TROUGH DURING
THE NEXT 6 TO 12 HOURS. UPPER LEVEL MOISTURE IS MOVING NORTHWARD
AS THE TROUGH NARROWS IN WIDTH AS COMPARED TO SIX HOURS AGO.
STRONG SHOWERS AND THUNDERSTORMS ARE WITHIN 15 NM TO 30 NM ON
EITHER SIDE OF THE LINE FROM 11N76W NEAR THE COLOMBIA COAST TO
12N76W 12N79W 13N79W. THE AREA OF CYCLONIC FLOW IS MUCH GREATER
IN COVERAGE TO THE WEST OF HISPANIOLA...FROM 11N TO CUBA BETWEEN
HAITI AND CENTRAL AMERICA. UPPER LEVEL MOISTURE FROM PARTS OF
THE EASTERN PACIFIC OCEAN AND COSTA RICA...PANAMA...COLOMBIA...
AND VENEZUELA IS PUSHED NORTHWARD ON THE SOUTHERN SIDE OF 15N78W
CYCLONIC CENTER AND ACCOMPANYING TROUGH.

THE ATLANTIC OCEAN...
AN ELONGATED UPPER LEVEL EAST-NORTHEAST TO WEST-SOUTHWEST
ORIENTED RIDGE STRETCHES FROM 30N30W TO 29N50W TO 27N70W TO
LAKE OKEECHOBEE IN FLORIDA. DRY AIR IN SUBSIDENCE GOES FROM 19N
TO 30N BETWEEN 30W AND 80W. A SURFACE RIDGE IS ALONG 26N57W TO
A 1017 MB HIGH PRESSURE CENTER THAT IS NEAR 27N70W TO 28N79W.
A DEEP LAYER TROUGH PASSES THROUGH 32N24W TO 25N36W TO 22N49W.
THIS TROUGH SUPPORTS THE COLD FRONT THAT PASSES THROUGH 32N28W
TO 27N40W TO 25N50W. BROAD ANTICYCLONIC FLOW IS TO THE SOUTH OF
THE LINE FROM GUADELOUPE IN THE EASTERN CARIBBEAN SEA TO 18N50W
18N40W 18N30W AND BEYOND THE CAPE VERDE ISLANDS. AN EASTERN
ATLANTIC OCEAN SURFACE RIDGE IS ALONG THE LINE FROM 24N25W
BEYOND 32N13W.

$$
MT



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