[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 231751
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI OCT 23 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1715 UTC.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE HAS AN ORIENTATION ALONG
20N34W 15N36W 10N38W MOVING WESTWARD 10 KT. STRONG SHOWERS
AND THUNDERSTORMS ARE FROM 15N TO 20N BETWEEN 32W AND 34W.
MULTILAYERED CONVECTIVE DEBRIS CLOUDS COVER THE REST
OF THE AREA FROM 10N TO 22N BETWEEN 26W AND 40W.

A SURFACE TROUGH IS ALONG 17N43W...TO A 1011 MB LOW PRESSURE
CENTER THAT IS NEAR 13N45W...TO 10N47W. THIS WHOLE FEATURE IS
MOVING WESTWARD 10 KT. FEW SHOWERS FROM 12N TO 15N BETWEEN 42W
AND 47W. HIGH CLOUDS ARE PASSING OVERHEAD. THIS FEATURE SHOWS
UP REALLY WELL IN VISIBLE SATELLITE IMAGERY.

...THE ITCZ...

FROM AFRICA NEAR 10N13W TO 8N20W 7N30W 6N50W TO 7N55W INTO
NORTHEASTERN VENEZUELA NEAR 7N60W. ISOLATED AND DISORGANIZED
MODERATE SHOWERS FROM 2N TO 10N BETWEEN AFRICA AND 30W.
SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS
ARE FROM 7N TO 8N BETWEEN 36W AND 40W...JUST TO THE SOUTH
OF THE 17N43W 10N38W SURFACE TROUGH. ISOLATED MODERATE
SHOWERS ARE ELSEWHERE FROM 2N TO 10N BETWEEN 30W AND 50W.

...DISCUSSION...

THE GULF OF MEXICO...
A DEEP LAYER TROUGH IS DRIVING THE CURRENT COLD FRONT ACROSS
THE GULF OF MEXICO. THE FRONT CROSSES OVER THE STATE LINE OF
SOUTHEASTERN MISSISSIPPI/SOUTHWESTERN ALABAMA TO 26N90W IN THE
CENTRAL GULF OF MEXICO...TO THE MEXICO GULF COAST NEAR 22N97W.
A SURFACE TROUGH EXTENDS FROM MEXICO COAST OF THE NORTHERN
ISTHMUS OF TEHUANTEPEC TO 22N95W NEAR THE FRONT. SCATTERED
MODERATE TO STRONG SHOWERS AND THUNDERSTORMS ARE WITHIN 30 NM
TO 60 NM ON EITHER SIDE OF 24N90W 27N87W. ISOLATED MODERATE
SHOWERS FROM 20N TO 22N BETWEEN 95W AND THE MEXICO COAST.

FROM THE WESTERN ATLANTIC OCEAN INTO THE WESTERN CARIBBEAN SEA...
A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM 27N76W TO
A CYCLONIC CIRCULATION CENTER THAT IS NEAR 23N78W...ACROSS
EASTERN CUBA TO A CARIBBEAN SEA CYCLONIC CENTER THAT IS NEAR
19N76W...TO PANAMA ALONG 80W. A 1007 MB LOW PRESSURE CENTER
IS ALONG THE NICARAGUA COAST NEAR 13N83W. STRONG SHOWERS
AND THUNDERSTORMS ARE FROM 11N TO 13N BETWEEN 81W AND 83W.
OTHER SHOWERS ARE POSSIBLE TO THE SOUTH OF 12N TO THE WEST
OF 75W. MULTILAYERED CLOUDS AND POSSIBLE LINGERING SHOWERS
AND THUNDERSTORMS ARE FROM THE WATERS JUST OFF THE COLOMBIA
COAST TO 20N BETWEEN 70W AND 77W.

THE BAHAMAS AND THE ADJACENT ATLANTIC OCEAN...
A SURFACE TROUGH IS ALONG 26N74W TO A 1009 MB LOW PRESSURE
CENTER THAT IS NEAR 22N76W...BETWEEN THE NORTHERN COAST OF
EASTERN CUBA AND THE BAHAMAS...TO 19N76W. THIS FEATURE MOVING
TOWARD THE WEST-NORTHWEST ACCOMPANIED BY DISORGANIZED CLOUDINESS
AND THUNDERSTORMS. SOME SLOW DEVELOPMENT IS POSSIBLE BEFORE
THE SYSTEM BECOMES ABSORBED BY A COLD FRONT IN A DAY OR TWO.
THE CHANCE THAT THIS SYSTEM MAY BECOME A TROPICAL OR SUBTROPICAL
CYCLONE DURING THE NEXT 48 HOURS IS LOW...LESS THAN 30 PERCENT.

THE REST OF THE CARIBBEAN SEA...
UPPER LEVEL CYCLONIC FLOW THAT WAS TO THE EAST OF 65W YESTERDAY
AFTERNOON NOW BARELY TOUCHES THE EXTREME EASTERN SECTIONS OF THE
CARIBBEAN SEA...TO THE EAST OF 61W. THIS CYCLONIC FLOW IS
ASSOCIATED WITH THE TAIL END OF AN ATLANTIC OCEAN TROUGH THAT
13N61W. DRY AIR IN SUBSIDENCE IS TO THE EAST OF 68W. UPPER LEVEL
MOISTURE THAT IS BETWEEN 68W AND 73W IS MOVING EASTWARD CROSSING
70W LITTLE BY LITTLE.

THE REST OF THE ATLANTIC OCEAN...
A CENTRAL ATLANTIC OCEAN DEEP LAYER TROUGH SUPPORTS A COLD FRONT
THAT PASSES THROUGH 32N35W TO 30N38W. A DISSIPATING COLD FRONT
CONTINUES FROM 30N38W TO 26N46W TO 25N52W. A PRE-FRONTAL TROUGH
IS ALONG 32N32W TO 26N40W TO 20N51W. BROKEN TO OVERCAST
MULTILAYERED CLOUDS AND SHOWERS AND THUNDERSTORMS ARE WITHIN
150 NM ON EITHER SIDE OF THE LINE THAT PASSES THROUGH 32N32W
26N40W 25N55W 25N69W.

$$
MT



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