000
AXNT20 KNHC 170518
TWDAT 

TROPICAL WEATHER DISCUSSION       
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT TUE OCT 17 2006

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN 
SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0445 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 34W/35W S OF 18N MOVING W AT 10-15 KT. 
BROAD MID LEVEL INVERTED-V SIGNATURE. CONVECTION IS BEING 
DISPLACED TO THE E BY UPPER LEVEL RIDGE. CLUSTERS OF SCATTERED 
MODERATE/STRONG CONVECTION ARE FROM 10N-16N BETWEEN 25W-34W. 

TROPICAL WAVE IS ALONG 62W/63W S OF 17N MOVING W 15-20 KT. SHARP 
LOW LEVEL INVERTED-V SIGNATURE. WAVE IS EMBEDDED IN AN AREA OF 
RELATIVELY DRY AIR WITH ANY SHOWERS/CONVECTION ASSOCIATED WITH 
UPPER LEVEL FEATURES.  

TROPICAL WAVE IS ALONG 90W/91W IS INLAND OVER S MEXICO AND IN 
THE E PACIFIC REGION. 

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 12N15W 9N26W 10N36W INLAND OVER 
SOUTH AMERICA NEAR 6N59W ACROSS THE SW CARIBBEAN INTO THE E 
PACIFIC REGION NEAR 10N84W. CLUSTERS OF SCATTERED MODERATE/ 
STRONG CONVECTION ARE FROM 7N-12N BETWEEN 17W-24W. CLUSTERS OF 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 2N-9N 
BETWEEN 10W-37W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE 
FROM 10N-15N BETWEEN 37W-46W. 

...DISCUSSION...
GULF OF MEXICO...
A FAIRLY STRONG UPPER TROUGH IS MOVING ACROSS THE CENTRAL PLAIN 
STATES TO THE MISSISSIPPI VALLEY WITH AN ASSOCIATED COLD FRONT 
EXTENDING FROM ARKANSAS ACROSS NW LOUISIANA TO A 998 MB LOW 
ALONG THE COAST OF TEXAS NEAR CORPUS CHRISTI CONTINUING S ALONG 
THE TEXAS COAST INTO MEXICO JUST S OF BROWNSVILLE. A SQUALL LINE 
IS TO THE E EXTENDING FROM 27N95W ACROSS CENTRAL LOUISIANA AND 
MISSISSIPPI. GALE FORCE WINDS ARE ACROSS THE N GULF N OF 27N 
FROM 88W-95W. THE REMAINDER OF THE GULF IS DOMINATED BY A LARGE 
UPPER HIGH ANCHORED NEAR 23N90W AND EXTENDING OVER THE W ATLC 
AND CARIBBEAN. REMAINDER OF THE GULF REMAINS SHOWER FREE 
TONIGHT. 

CARIBBEAN SEA...
THE LARGE UPPER RIDGE ANCHORED IN THE GULF OF MEXICO EXTENDS E 
ACROSS THE CARIBBEAN TO 67W DRYING OUT THE AREA EXCEPT SOME 
REMAINING AFTERNOON SHOWERS THAT DEVELOPED OVER CUBA AND HAITI. 
AN UPPER TROUGH OVER THE W/CENTRAL ATLC DIPS S OVER THE 
REMAINDER OF THE CARIBBEAN WITH A 1008 MB LOW REMAINS N OF 
PUERTO RICO AND A SURFACE TROUGH EXTENDING S ACROSS PUERTO RICO 
TO 14N69W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS DOT THE E 
CARIBBEAN WITHIN 120 NM OF A LINE FROM THE ABC ISLANDS TO ACROSS 
THE VIRGIN ISLANDS. 

ATLANTIC OCEAN...
THE LARGE RIDGE ANCHORED IN THE GULF OF MEXICO EXTENDS ACROSS 
THE W ATLC TO 67W DRYING OUT THE AREA. UPPER LEVEL TROUGH 
EXTENDS INTO THE W/CENTRAL ATLC E OF BERMUDA NEAR 32N60W S  
ALONG 24N62W INTO THE E CARIBBEAN OVER THE VIRGIN ISLANDS WITH 
THE ASSOCIATED WEAKENING COLD FRONT ENTERING THE REGION NEAR 
32N54W EXTENDING S 27N57. A SURFACE TROUGH EXTENDS FROM 25N61W 
TO A 1008 MB LOW N OF PUERTO RICO NEAR 19N66W. SCATTERED 
SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 225 NM E OF THE FRONT 
AND THE SURFACE TROUGH. A SHARP UPPER RIDGE EXTENDS FROM NEAR 
16N56W N TO BEYOND 32N48W. NARROW UPPER LEVEL TROUGH EXTENDS 
FROM THE E ATLC THROUGH 32N23W SW TO NEAR 18N47W. AT THE 
SURFACE...A 1020 MB HIGH IS LOCATED NEAR 31N40W WITH A RIDGE 
COVERING THE AREA N OF 20N FROM 25W-50W. AN UPPER HIGH IS IN THE 
E TROPICAL ATLC NEAR 12N22W WITH A RIDGE EXTENDING N TO THE 
CANARY ISLANDS DISPLACING CONVECTION ASSOCIATED WITH THE 
TROPICAL WAVE ALONG 34W/35W.

$$
WALLACE