000
AXNT20 KNHC 171015
TWDAT 

TROPICAL WEATHER DISCUSSION       
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0945 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 35W/36W S OF 18N MOVING W AT 10 KT. BROAD 
LOW/MID LEVEL INVERTED-V SIGNATURE. CONVECTION IS BEING 
DISPLACED TO THE E BY UPPER LEVEL RIDGE. CLUSTERS OF SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION ARE FROM 10N-17N BETWEEN 
30W-34W. 

TROPICAL WAVE IS ALONG 64W S OF 18N MOVING W 10-15 KT. SHARP LOW 
LEVEL INVERTED-V SIGNATURE. WAVE IS MOVING TOWARD THE LOW/TROUGH 
OVER PUERTO RICO ENHANCING SCATTERED SHOWERS/THUNDERSTORMS 
WITHIN 90 NM OF LINE FROM 15N65W ACROSS THE LEEWARD ISLANDS TO 
20N61W. 

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 12N14W 9N20W 13N33W 7N50W INLAND 
OVER SOUTH AMERICA NEAR 7N61W ACROSS THE SW CARIBBEAN INTO THE E 
PACIFIC REGION NEAR 10N84W. SCATTERED/NUMEROUS STRONG CONVECTION 
IS FROM 10N-15N BETWEEN 24W-29W. CLUSTERS OF SCATTERED MODERATE/ 
ISOLATED STRONG CONVECTION ARE FROM 2N-13N BETWEEN 11W-37W. 
CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 10N-13N 
BETWEEN 37W-49W. 

...DISCUSSION...
GULF OF MEXICO...
A FAIRLY STRONG UPPER TROUGH IS MOVING ACROSS THE MISSISSIPPI 
VALLEY TOWARD THE NE US AROUND THE LARGE UPPER HIGH ANCHORED IN 
THE GULF OF MEXICO. THE ASSOCIATED COLD FRONT EXTENDS FROM A 
1002 MB LOW ALONG THE W COAST OF LOUISIANA SW TO THE COAST OF 
TEXAS NEAR BROWNSVILLE. THE SQUALL LINE PRECEDES THE FRONT AND 
IS NOT AS INTENSE AS 6 HOURS AGO EXTENDING FROM 28N94W TO 
CENTRAL MISSISSIPPI. GALE FORCE WINDS REMAIN ACROSS THE N GULF. 
THE REMAINDER OF THE GULF IS DOMINATED BY THE LARGE UPPER HIGH 
ANCHORED NEAR 26N90W 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 KEEPING THE AREA DRY. AN UPPER 
TROUGH OVER THE W/CENTRAL ATLC DIPS S OVER THE REMAINDER OF THE 
CARIBBEAN WITH A 1008 MB LOW ALONG THE N COAST OF PUERTO RICO 
AND A SURFACE TROUGH EXTENDING S TO 16N68W. SCATTERED SHOWERS/ 
ISOLATED THUNDERSTORMS DOT THE E CARIBBEAN E OF 72W TO OVER THE 
LESSER ANTILLES. 

ATLANTIC OCEAN...
THE LARGE RIDGE ANCHORED IN THE GULF OF MEXICO EXTENDS ACROSS 
THE W ATLC TO 67W KEEPING THE AREA DRY. UPPER LEVEL TROUGH 
EXTENDS INTO THE W/CENTRAL ATLC E OF BERMUDA NEAR 32N59W S  
ALONG 24N62W INTO THE E CARIBBEAN OVER THE VIRGIN ISLANDS WITH 
THE ASSOCIATED WEAKENING COLD FRONT ENTERING THE REGION NEAR 
32N53W EXTENDING S 27N57W. A SURFACE TROUGH EXTENDS FROM 25N62W 
TO A 1008 MB LOW ALONG THE N COAST OF PUERTO RICO. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 75 NM OF LINE FROM 
27N56W TO PUERTO RICO NEAR 19N66W. SCATTERED SHOWERS/ISOLATED 
THUNDERSTORMS ARE E OF THE FRONT WITHIN 125 NM OF LINE FROM 
22N58W TO 33N49W. A SHARP UPPER RIDGE EXTENDS FROM NEAR 16N56W N 
TO BEYOND 32N47W. NARROW UPPER LEVEL TROUGH EXTENDS FROM THE E 
ATLC THROUGH 32N22W SW TO NEAR 20N43W. AT THE SURFACE...A SMALL 
RIDGE COVERS THE AREA N OF 24N FROM 30W-50W WITH A 1020 MB HIGH 
LOCATED NEAR 30N39W. AN UPPER RIDGE COVERS THE FAR E ATLC S OF 
THE CANARY ISLANDS E OF 30W DISPLACING CONVECTION ASSOCIATED 
WITH THE TROPICAL WAVE ALONG 35W/36W.

$$
WALLACE