000
AXNT20 KNHC 142345
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
805 PM EDT WED OCT 14 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2315 UTC.

...TROPICAL WAVES...

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 62W/63W TO THE SOUTH OF
15N MOVING WEST 15 KT. UPPER LEVEL CYCLONIC FLOW IS ON TOP OF 
THIS WAVE. CONVECTIVE DEBRIS CLOUDS FROM EARLIER AND ALREADY
DISSIPATED PRECIPITATION COVER THE WATERS FROM 12N TO 15N
BETWEEN 60W AND 65W. ISOLATED MODERATE SHOWERS AND POSSIBLE
THUNDERSTORMS ARE IN VENEZUELA FROM 9N TO 11N BETWEEN 63W AND 
65W.

...THE ITCZ...

FROM AFRICA NEAR 11N14W TO 10N20W TO 7N30W 9N50W INTO 
NORTHEASTERN VENEZUELA NEAR 10N62W. SCATTERED STRONG SHOWERS
AND THUNDERSTORMS FROM 7N TO 11N BETWEEN 20W AND 26W. OTHER 
MODERATE SHOWERS ARE ELSEWHERE FROM 6N TO 11N BETWEEN 18W AND 
30W. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE 
FROM 4N TO 10N BETWEEN 33W AND 50W...AND FROM 4N TO 14N BETWEEN 
50W AND 60W. ONE SURFACE TROUGH IN THE ITCZ IS ALONG 30W/31W 
FROM 5N TO 11N. A SECOND TROUGH IS ALONG 50W/51W FROM 6N TO 15N. 

...DISCUSSION...

THE GULF OF MEXICO...
BROAD UPPER LEVEL CYCLONIC FLOW FROM A TROUGH THAT IS MOVING 
ACROSS THE SOUTHEASTERN U.S.A. AND THE NORTHEASTERN GULF COAST
CUTS INTO THE AREA TO THE NORTHEAST OF THE LINE FROM THE FLORIDA 
WEST COAST NEAR 28N83W TO THE UPPER TEXAS COAST. SHOWERS ARE 
POSSIBLE ACROSS THE OPEN WATERS OF THE GULF TO THE NORTH OF 23N
TO THE EAST OF 94W. SHOWERS AND POSSIBLE THUNDERSTORMS ARE OVER
THE COASTAL PLAINS WITHIN 30 NM ON EITHER SIDE OF 30N BETWEEN
WESTERN LOUISIANA AND NORTHEASTERN FLORIDA.

THE CARIBBEAN SEA...
AN UPPER LEVEL TROUGH EXTENDS FROM THE ATLANTIC OCEAN NEAR 
15N58W TO 14N63W TO 12N73W TO THE COAST OF PANAMA NEAR 9N81W.
CLUSTERS OF CLOUDS AND POSSIBLE SHOWERS ARE IN THE CARIBBEAN SEA 
AND ADJACENT ATLANTIC OCEAN AND ACROSS SOME OF THE ISLANDS FROM
16N TO 20N AND CUBA BETWEEN 60W AND THE YUCATAN PENINSULA AND
BELIZE. THE CLOUDS AND PRECIPITATION ARE SURROUNDED COMPLETELY 
BY DRY AIR IN SUBSIDENCE. STRONG SHOWERS AND THUNDERSTORMS ARE 
INLAND FROM COLOMBIA TO PANAMA FROM 8N TO 11N BETWEEN 73W AND 
81W. 

THE ATLANTIC OCEAN...
ONE COLD FRONT PASSES THROUGH 32N56W TO 27N70W BEYOND 31N80W.
THIS FIRST FRONT IS EXPECTED TO RECEIVE A JOLT OF ENERGY WHEN
A SECOND COLD FRONT THAT CURRENTLY IS ABOUT 90 NM TO 120 NM TO 
THE NORTHWEST OF IT MERGES WITH THE FIRST ONE IN ABOUT 12 TO 
24 HOURS. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS 
ARE FROM 29N BEYOND 32N BETWEEN 50W AND 56W. THESE FRONTS ARE 
COMPARATIVELY SHALLOW SINCE THEY HAVE LOST THEIR UPPER LEVEL 
ATMOSPHERIC SUPPORT. AN UPPER LEVEL RIDGE IS ALONG 30N60W TO 
ANDROS ISLAND IN THE BAHAMAS TO THE MEXICO GULF COAST NEAR 
22N97W. A SMALL AREA OF CYCLONIC FLOW IS NEAR 32N56W. AN UPPER 
LEVEL TROUGH PASSES THROUGH 32N28W TO 26N27W TO 17N30W TO 
13N35W. A SURFACE TROUGH STARTS FROM A 1014 MB LOW PRESSURE 
CENTER NEAR 30N32W TO 27N30W AND 24N40W. ISOLATED MODERATE 
SHOWERS AND POSSIBLE THUNDERSTORMS ARE FROM 26N TO 30N
BETWEEN 23W AND 30W. 

$$
MT