000
AXNT20 KNHC 111013
TWDAT 

TROPICAL WEATHER DISCUSSION           
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI AUG 11 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 45W/46W S OF 19N MOVING W 15-20 KT. WAVE 
CONTINUES TO HAVE A WELL DEFINED INVERTED V-SHAPE CURVATURE 
HOWEVER LACKS DEEP CONVECTION DUE A VERY DRY ENVIRONMENT. 
ISOLATED THUNDERSTORMS ARE FROM 11N-16N BETWEEN 43W-48W. 

TROPICAL WAVE IN THE CARIBBEAN IS ALONG 68W/69W S OF 20N MOVING 
W NEAR 20 KT. WAVE IS ON THE WESTERN EDGE OF A BROAD UPPER HIGH 
ENHANCING SCATTERED MODERATE/ISOLATED STRONG CONVECTION WITHIN 
60/75 NM OF LINE 16N67W TO THE COAST OF HISPANIOLA NEAR 18N71W. 
    
TROPICAL WAVE IS NO LONGER IN THE ATLC BASIN. 

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 13N15W 6N31W 13N47W 10N56W 11N66W. 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 150 NM N 
OF THE AXIS FROM 35W-40W AND FROM 50W-55W. CLUSTERS OF SIMILAR 
CONVECTION ARE WITHIN 150/180 NM OF THE AXIS E OF 20W TO THE 
COAST OF AFRICA AND WITHIN 180 NM S OF THE AXIS FROM 37W-42W.  

...DISCUSSION...
GULF OF MEXICO...
THE UPPER LEVEL LOW REMAINS IN THE W GULF NEAR 25N95W COVERING 
THE AREA W OF 86W. AN UPPER RIDGE EXTENDS FROM THE CENTRAL 
MISSISSIPPI VALLEY SE INTO THE W ATLC GIVING THE REMAINDER OF 
THE GULF SE UPPER FLOW AND DRY UPPER AIR. AT THE SURFACE...A 
RIDGE EXTENDS FROM THE W ATLC TO FLORIDA WITH A 1016 MB HIGH IN 
THE NE GULF NEAR 27N84W. SOME UPPER MOISTURE REMAINS OVER THE SW 
GULF BUT IS NOT ENOUGH TO SUPPORT ANY SHOWER ACTIVITY. 
THUS...THE GULF IS RELATIVE QUIET THIS MORNING.
 
CARIBBEAN SEA...
AN UPPER RIDGE EXTENDS FROM NEAR W/CENTRAL PANAMA TO THE YUCATAN 
CHANNEL PRODUCING SHOWERS/THUNDERSTORMS INLAND AND ALONG THE 
COAST FROM W PANAMA THROUGH THE YUCATAN PENINSULA. THE UPPER 
RIDGE OVER THE W ATLC DIPS S OVER CUBA GIVING ENOUGH DIFFLUENCE 
TO DEVELOP WIDELY ISOLATED SHOWERS/THUNDERSTORMS N OF 17N W OF 
75W. THE E CARIBBEAN IS UNDER THE INFLUENCE OF AN UPPER RIDGE 
THAT COVERS THE CENTRAL AND E ATLC ENHANCING CONVECTION 
ASSOCIATED WITH THE TROPICAL WAVE. MODERATE/STRONG TRADEWINDS 
ARE ACROSS THE CENTRAL CARIBBEAN. 

ATLANTIC OCEAN...
UPPER RIDGE EXTENDS FROM OVER THE CENTRAL MISSISSIPPI VALLEY 
INTO THE W ATLC ACROSS THE GEORGIA COAST ESE TO NEAR 27N64W 
BRINGING WITH IT SHOWERS/THUNDERSTORMS N OF 30N W OF 67W TO 
INLAND OVER THE SE US. VERY LARGE UPPER RIDGE COVERS MOST OF THE 
ATLC S OF 30N E OF 55W. A NARROW UPPER TROUGH EXTENDS FROM 
25N61W TO THE MONA PASSAGE. AN DEEP LAYERED TROUGH IS JUST N OF 
THE REGION E OF BERMUDA WITH THE ASSOCIATED STATIONARY FRONT 
BEGINNING TO DIE OUT ALONG 33N. THIS IS STILL GIVING THE AREA 
FROM 30N-33N BETWEEN 55W-67W SCATTERED SHOWERS AND ISOLATED 
THUNDERSTORMS. A SECOND DEEP LAYERED TROUGH IS N OF THE 
E/CENTRAL ATLC N OF 30N FROM 35W-43W WITH A WEAK SURFACE TROUGH 
EXTENDING THROUGH 32N36W SW TO 27N40W. HOWEVER...DUE TO THE 
ABUNDANCE OF DRY AIR...SHOWER ACTIVITY IS SEVERELY LIMITED. THE 
REMAINDER OF THE SURFACE ATLC IS DOMINATED BY A SURFACE RIDGE 
WITH A SERIES OF HIGHS EXTENDING ACROSS THE ATLC TO THE GULF 
OF MEXICO THROUGH A 1020 MB HIGH IN THE E ATLC NEAR 27N30W...A 
1018 MB HIGH IN THE CENTRAL ATLC NEAR 25N52W...AND A 1017 MB 
HIGH IN THE W ATLC NEAR 26N71W. THIS IS GIVING THE ENTIRE AREA 
LITTLE IN THE WAY OF CLOUDS MUCH LESS SHOWER ACTIVITY. 

$$
WALLACE