000
AXNT20 KNHC 290541
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN JUL 29 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 
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...METEOROLOGICAL ANALYSIS... 
WEATHER OBSERVATIONS...AND RADAR.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...SPECIAL FEATURE...
SURFACE TROUGH IS LOCATED FROM 29N72W INTO THE CENTRAL BAHAMAS 
TO 22N76W. ENVIRONMENTAL CONDITIONS ARE FORECAST TO BECOME MORE 
FAVORABLE FOR TROPICAL CYCLONE DEVELOPMENT AS THE SYSTEM MOVES 
NORTH-NORTHEASTWARD OVER THE NEXT DAY OR TWO. RIDGING ALOFT 
COVERS THE AREA SURROUNDING THE TROUGH AND SCATTERED SHOWERS AND 
TSTMS ARE LOCATED FROM 24N-30N E OF TROUGH TO 71W.

...TROPICAL WAVES...
TROPICAL WAVE IS OVER THE E ATLC FROM 4N-18N ALONG 23W MOVING W 
10-15 KT. CONVECTION IS CONFINED TO THE AREA ALONG THE ITCZ.    

TROPICAL WAVE FROM 5N-18N ALONG 43W MOVING W 10 KT. MODERATE 
TO ISOLATED STRONG CONVECTION IS WITHIN 120 NM E OF WAVE FROM 
7N-9N.

TROPICAL WAVE S OF 19N ALONG 57W/58W MOVING W 10-15 KT. NO 
CONVECTION ASSOCIATED WITH THE WAVE.

TROPICAL WAVE LOCATED OVER THE FAR WESTERN CARIBBEAN S OF 19N 
ALONG 88W MOVING W 10 KT. NO CONVECTION OVER THE CARIBBEAN BUT 
STRONG THUNDERSTORMS COVER SOUTHERN HONDURAS AND EL SALVADOR.  

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 11N15W 9N30W 11N45W 9N61W. SCATTERED 
MODERATE CONVECTION IS WITHIN 110 NM S OF AXIS FROM 21W-26W. 
SCATTERED MODERATE TO STRONG CONVECTION WITHIN 60 NM EITHER SIDE 
OF AXIS FROM 33W-35W.

...DISCUSSION...
GULF OF MEXICO
UPPER LEVEL RIDGE EXTENDS FROM CENTRAL MEXICO INTO THE NW GULF 
OF MEXICO TO LOUISIANA. ANTICYCLONIC FLOW COVES MUCH OF THE GULF 
OF MEXICO. EARLIER CONVECTIVE ACTIVITY HAS DISSIPATED WITH ONLY 
MID TO UPPER LEVEL DEBRIS CLOUDS LEFT ACROSS THE AREA. 

CARIBBEAN
AN INVERTED UPPER LEVEL TROUGH WITH AXIS FROM THE NICARAGUA
HONDURAS BORDER NE ACROSS JAMAICA TO EASTERN CUBA. EARLIER 
STRONG TSTMS OVER CUBA HAVE DISSIPATED BUT A FEW TSTMS REMAIN 
OVER THE NW CARIBBEAN JUST S OF CUBA. AN ANTICYCLONIC 
CIRCULATION IS CENTERED OVER THE CENTRAL CARIBBEAN NEAR 14N76W 
WITH ANOTHER TROUGH E OF ANTICYCLONE IN THE EASTERN CARIBBEAN. 
DRY STABLE AIR WITH MID/UPPER LEVEL SUBSIDENCE COVERS THE E 
CARIBBEAN...HOWEVER
A FEW SHOWERS ARE MOVING INTO THE WINDWARD ISLANDS WITH AN 
APPROACHING TROPICAL WAVE.

ATLANTIC
DEEP LAYER TROUGH EXTENDS FROM 31N74W ACROSS THE NORTHERN 
BAHAMAS INTO THE STRAITS OF FLORIDA. DOWNSTREAM UPPER LEVEL
ANTICYCLONE IS LOCATED NEAR 24N67W WITH RIDGE N TO 31N67W.
DIFFLUENCE ALOFT BETWEEN THE TROUGH AND ANTICYCLONE IS ENHANCING 
CONVECTIVE ACTIVITY ASSOCIATED WITH TROUGH DISCUSSED IN SPECIAL 
FEATURES SECTION. A WELL-DEFINED ELONGATED MIDDLE/UPPER LEVEL 
CYCLONIC CIRCULATION IS CENTERED NEAR 32N62W AND IS DRIFTING NE. 
TROUGH EXTENDS SOUTHWARD FROM THE CIRCULATION TO NEAR 22N60W. 
BROAD RIDGING ALOFT COVERS MOST OF THE EASTERN ATLC WITH 
MODERATE TO STRONG SUBSIDENCE AND DRY STABLE AIR N OF THE ITCZ. 
AN UPPER LEVEL TROUGH EMBEDDED IN THE RIDGE EXTENDS FROM 
CYCLONIC CIRCULATION NEAR 31N37W TO 27N43W.

$$
DGS