000
AXNT20 KNHC 281034
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
805 AM EDT WED OCT 28 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 15N 
MOVING WEST 10 KT. STRONG SHOWERS AND THUNDERSTORMS FROM 12N TO 
14N BETWEEN 26W AND 28W.

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 49W/50W TO THE SOUTH
OF 14N MOVING WEST 10 KT. ISOLATED MODERATE SHOWERS AND POSSIBLE
THUNDERSTORMS ARE FROM 4N TO 11N BETWEEN 46W AND 50W.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 62W/63W TO THE SOUTH OF 
17N MOVING WESTWARD 10 KT. ISOLATED MODERATE SHOWERS COVER 
AND/OR ARE AROUND THE EASTERN CARIBBEAN SEA ISLANDS FROM 14N
TO 18N BETWEEN 60W AND 63W. BROAD LARGE-SCALE UPPER LEVEL
CYCLONIC FLOW COVERS THE CARIBBEAN SEA TO THE EAST OF 87W.

...ITCZ...

7N11W 9N20W 12N28W 8N40W 8N50W 8N62W ACROSS NORTHERN GUYANA
INTO NORTHEASTERN VENEZUELA. ISOLATED MODERATE SHOWERS ARE
ELSEWHERE FROM 3N TO 6N BETWEEN AFRICA AND 20W...FROM 6N TO
12N BETWEEN 20W AND 30W...AND ELSEWHERE FROM 7N TO 12N
BETWEEN 30W AND 60W.

...DISCUSSION...

THE GULF OF MEXICO...
THE CYCLONIC FLOW WITH THE UPPER LEVEL TROUGH THAT SUPPORTS THE 
CURRENT FRONTAL BOUNDARY IS INLAND...TO THE NORTH OF THE U.S.A. 
GULF COAST STATES. AN UPPER LEVEL RIDGE RUNS FROM SOUTHERN
GUATEMALA THROUGH THE NORTHERN YUCATAN PENINSULA...BEYOND NORTH
CENTRAL FLORIDA. UPPER LEVEL SOUTHWESTERLY WINDS ARE ON THE 
WESTERN SIDE OF THE RIDGE...UPPER LEVEL NORTHERLY WINDS ARE ON 
THE EASTERN SIDE OF THE RIDGE. THE FRONTAL BOUNDARY 28/0600 UTC
WAS COLD FROM THE FLORIDA PANHANDLE TO THE CENTRAL GULF 
WATERS...AND THEN STATIONARY FROM THERE CURVING SOUTHWESTWARD
TO THE EASTERN ISTHMUS OF TEHUANTEPEC OF MEXICO. THE FRONTAL 
BOUNDARY HAS BECOME STATIONARY AT 28/0900 UTC...AND IT APPEARS
TO BE STARTING TO DISSIPATE WITH TIME TO THE WEST OF 90W.

THE CARIBBEAN SEA...
BROAD LARGE-SCALE UPPER LEVEL CYCLONIC FLOW IS ROLLING ACROSS 
THE CARIBBEAN SEA...COVERING PRACTICALLY THE WHOLE AREA.
THE ONLY PART OF THE CARIBBEAN SEA THAT IS NOT BEING COVERED
BY THE CYCLONIC FLOW IS THE AREA THAT IS TO THE WEST OF 87W.
THE CENTER OF THE CYCLONIC FLOW IS NEAR 17N74W TO THE SOUTH
OF HAITI. ISOLATED MODERATE SHOWERS ARE FROM 16N TO 18N BETWEEN
60W AND 80W...NOT COUNTING THE PRECIPITATION THAT MAY BE NEAR
THE 62W/63W TROPICAL WAVE. UPPER LEVEL FLOW THAT IS MOVING 
NORTHWARD FROM THE AREA OF THE EASTERN PACIFIC OCEAN THAT IS 
JUST TO THE WEST OF COLOMBIA AND TO THE SOUTH OF PANAMA IS
BEING SHOT EASTWARD TO THE SOUTH OF 12N. STRONG SHOWERS AND
THUNDERSTORMS ARE FROM CENTRAL AMERICA AND 9N IN COLOMBIA
TO 12N BETWEEN 74W IN COLOMBIA AND THE SOUTHEASTERN COAST
OF NICARAGUA.

THE ATLANTIC OCEAN...
LARGE-SCALE UPPER LEVEL ANTICYCLONIC FLOW COVERS THE AREA TO
THE NORTH OF 20N TO THE WEST OF 30W. THIS ANTICYCLONIC FLOW IS
ON TOP OF THE CYCLONIC FLOW THAT IS MOVING FROM THE ATLANTIC
OCEAN INTO THE CARIBBEAN SEA. WHATEVER IS LEFT OF THE AREA
OF A 700 MB-TO-500 MB VORTICITY MAXIMUM FROM 24 HOURS AGO 
IS NEAR 27N62W. CLOUDS WITH THIS FEATURE ARE FROM 26N TO 28N 
BETWEEN 60W AND 63W. AN EASTERN ATLANTIC OCEAN DEEP LAYER
TROUGH PASSES THROUGH THE MADEIRA ARCHIPELAGO TO THE CANARY 
ISLANDS...TO 23N25W AND 16N28W. A SURFACE TROUGH IS ALONG
32N18W 29N20W TO 24N24W.

$$
MT