[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 221038
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI 22 OCT 2004

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN
SECTIONS OF SOUTH AMERICA...AND ATLC OCEAN TO THE AFRICAN
COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...
AND METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND
SATELLITE IMAGERY THROUGH 1015 UTC.

...TROPICAL WAVES...
CENTRAL ATLANTIC TROPICAL WAVE ALONG 60W SOUTH OF 18N MOVING
WEST 15 KT. THE WAVE IS ENCOUNTERING UPPER LEVEL WESTERLY TO
NORTHWESTERLY SHEAR AS IT MOVES UNDER A RIDGE. SCATTERED STRONG
SHOWERS AND THUNDERSTORMS WITHIN 30 TO 40 NM ON EITHER SIDE OF
14N63W 16N61W 16N60W 17N58W MAY BE DUE MORE TO THE FACT THAT
THE PRECIPITATION IS OCCURRING TO THE EAST OF AN AREA OF UPPER
LEVEL DIFFLUENT FLOW RATHER THAN BECAUSE OF THE WAVE. A MIDDLE
TO UPPER LEVEL TROUGH CONTINUES FROM THE WESTERN ATLANTIC OCEAN
TO WESTERN NICARAGUA. UPPER LEVEL SOUTHWESTERLY WINDS
ARE SET TO CUT ACROSS THE WAVE AS IT MOVES TO THE WEST.

WESTERN CARIBBEAN SEA TROPICAL WAVE ALONG 83W SOUTH OF 20N
MOVING WEST 10 KT. A MIDDLE TO UPPER LEVEL TROUGH CONTINUES
FROM THE WESTERN ATLANTIC OCEAN TO WESTERN NICARAGUA. UPPER
LEVEL NORTHERLY WINDS AND SOUTHWESTERLY WINDS ARE CUTTING
ACROSS THE WAVE. THE STRONG SHOWERS AND THUNDERSTORMS IN THE
EASTERN PACIFIC OCEAN COASTAL AREAS OF CENTRAL AMERICA FROM
9N82W NEAR PANAMA TO 12N87W TO 13N92W TO JUST EAST OF THE GULF
OF TEHUANTEPEC OF MEXICO NEAR 15N93W ARE RELATED TO DIFFLUENT
FLOW WEST OF THE WESTERN ATLANTIC OCEAN-TO-WESTERN NICARAGUA
TROUGH.

...ITCZ...
ITCZ 7N12W 5N27W 6N36W 8N50W 8N58W...10N61W 11N68W...12N71W
11N82W...11N84W 11N90W. SCATTERED MODERATE TO ISOLATED STRONG
SHOWERS AND THUNDERSTORMS FROM NORTHWESTERN VENEZUELA INTO THE
SOUTHWESTERN CARIBBEAN SEA FROM 10N TO 13N BETWEEN 70W AND 80W.
ISOLATED TO WIDELY SCATTERED MODERATE/LOCALLY STRONG SHOWERS
AND THUNDERSTORMS FROM 2N TO 9N EAST OF 44W...AND FROM 6N TO
10N BETWEEN 48W AND 56W.

...DISCUSSION...

THE GULF OF MEXICO...THE WESTERN ATLANTIC OCEAN...AND
THE WESTERN CARIBBEAN SEA...
BROAD UPPER LEVEL ANTICYCLONIC FLOW WITH A CENTER NEAR 23N97W IN
NORTHEAST COASTAL MEXICO ABOUT 150 NM SOUTH OF DEEP SOUTH TEXAS.
UPPER LEVEL ANTICYCLONIC FLOW STRETCHES FROM MISSOURI TO
SOUTHERN MEXICO BETWEEN THE EAST-CENTRAL GULF OF MEXICO AND
110W. THIS RIDGE HAS BEEN AMPLIFYING A GOOD DEAL DURING THE LAST
24 HOURS. MIDDLE TO UPPER LEVEL DRY AIR FROM 14N TO 30N BETWEEN
80W AND 105W. UPPER LEVEL NORTHERLY FLOW IN THE GULF OF MEXICO
EAST OF 90W...ON THE EASTERN SIDE OF THE ANTICYCLONIC FLOW...BUT
AT THE SAME TIME ON THE WESTERN SIDE OF THE WESTERN ATLANTIC-TO-
WESTERN NICARAGUA MIDDLE TO UPPER LEVEL TROUGH. ANOTHER TROUGH
IS MOVING INTO THIS SAME TROUGH...FORTIFYING IT AND CARRYING
WITH IT A SURFACE COLD FRONT WHICH PASSES THROUGH 32N66W...JUST
WEST OF BERMUDA...TO THE NORTHERN BAHAMAS NEAR 26N78W...AND
CURVING NORTHWESTWARD TO THE FLORIDA PANHANDLE NEAR 31N88W.
ISOLATED MODERATE TO LOCALLY STRONG SHOWERS AND THUNDERSTORMS
NORTH OF 19N BETWEEN 70W AND 84W IN THE ATLANTIC OCEAN...OVER
FLORIDA/CUBA/THE BAHAMAS...AND IN THE EASTERN GULF OF MEXICO.

THE CARIBBEAN SEA...
UPPER LEVEL NORTHERLY FLOW IN MUCH OF THE AREA NORTH OF 14N
WEST OF 80W...SWITCHING TO UPPER LEVEL SOUTHWESTERLY FLOW AS
EVERYTHING MOVES TOWARD THE NORTH CENTRAL CARIBBEAN SEA ISLANDS.
ALL THIS IS RELATED TO THE MIDDLE TO UPPER LEVEL TROUGH FROM
34N70W IN THE ATLANTIC OCEAN...ACROSS THE BAHAMAS AND CUBA...TO
20N78W...TO 12N87W IN WESTERN NICARAGUA. BROAD UPPER LEVEL
ANTICYCLONIC FLOW ELSEWHERE EAST OF THE MIDDLE TO UPPER LEVEL
TROUGH. MIDDLE TO UPPER LEVEL DRY AIR IN THE ATLANTIC OCEAN
WEST OF 30N71W 24N73W 20N76W.

THE SUBTROPICAL ATLANTIC...
MIDDLE TO UPPER LEVEL TROUGH FROM THE WESTERN ATLANTIC THROUGH
34N69W TO 31N75W...ACROSS THE BAHAMAS TO CUBA NEAR 23N77W...
INTO THE NORTHWESTERN CARIBBEAN SEA NEAR 18N80W...TO WESTERN
NICARAGUA NEAR 12N87W. BROKEN TO OVERCAST MULTILAYERED CLOUDS
AND ISOLATED TO WIDELY SCATTERED MODERATE/LOCALLY STRONG SHOWERS
AND THUNDERSTORMS WITHIN 400 NM EAST OF THE 30N71W 20N76W
BOUNDARY OF MIDDLE TO UPPER LEVEL DRY AIR. BROAD UPPER LEVEL
ANTICYCLONIC FLOW MOVES SMOOTHLY AND GENTLY THROUGH THE REST OF
THE ATLANTIC OCEAN NORTH OF 20N. UPPER LEVEL ANTICYCLONIC FLOW
FROM A SEPARATE UPPER LEVEL RIDGE COVERS THE ATLANTIC WATERS
SOUTH OF 20N BETWEEN 50W AND 67W. UPPER LEVEL WESTERLIES PREVAIL
ELSEWHERE TOWARD AFRICA.

THE TROPICAL ATLANTIC...
UPPER LEVEL ANTICYCLONIC FLOW FROM A SEPARATE UPPER LEVEL RIDGE
COVERS THE ATLANTIC WATERS SOUTH OF 20N BETWEEN 50W AND 67W.
BROAD UPPER LEVEL ANTICYCLONIC FLOW ALSO COVERS THE REST OF THE
AREA SOUTH OF 20N BETWEEN 20W AND 50W IN STILL ANOTHER SEPARATE
AREA OF ANTICYCLONIC FLOW.

$$
MT


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