000
AXNT20 KNHC 301054
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT WED JUL 30 2008

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1015 UTC.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 18W/19W SOUTH OF 18N
MOVING WEST ABOUT 15 KT. A 1006 MB LOW PRESSURE CENTER IS ALONG 
THE WAVE NEAR 14.5N. SCATTERED MODERATE SHOWERS TO ISOLATED 
STRONG THUNDERSTORMS ARE FROM 14N TO 17N BETWEEN 18W AND 21W. 
ANY KIND OF DEVELOPMENT OF THIS SYSTEM WILL BE SLOW TO OCCUR.

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 21N49W 15N52W 8N54W. 
THE ENVELOPE OF SURFACE CYCLONIC WIND FLOW COVERS THE ATLANTIC
OCEAN FROM 10N TO 21N BETWEEN 40W AND 60W. ISOLATED MODERATE 
SHOWERS ARE IN THE AREA UNDER THE CYCLONE ENVELOPE.

A CENTRAL CARIBBEAN SEA TROPICAL WAVE IS ALONG 71W/72W SOUTH OF 
19N MOVING WEST 15 KT. ISOLATED MODERATE SHOWERS FROM 14N TO 20N
BETWEEN 64W AND 76W MAY OR MAY NOT BE RELATED TO THIS WAVE.

...THE ITCZ...
9N21W 9N31W 12N50W 10N60W. ISOLATED TO WIDELY SCATTERED MODERATE 
SHOWERS TO LOCALLY STRONG THUNDERSTORMS FROM 5N TO 11N BETWEEN 
18W AND 37W...AND FROM 5N TO 10N BETWEEN 40W AND 50W. ONE SMALL 
CELL OF PRECIPITATION WITHIN A 15 NM RADIUS OF 9N59W ALONG THE 
COASTS OF GUYANA AND VENEZUELA.

...DISCUSSION...

THE GULF OF MEXICO...
A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM THE SOUTHWEST 
LOUISIANA COAST TO THE MEXICO COAST SURROUNDED BY DRY AIR IN 
SUBSIDENCE ON THE WESTERN SIDE. MIDDLE TO UPPER LEVEL CYCLONIC 
FLOW COVERS THE ATLANTIC OCEAN SOUTH OF 29N WEST OF 67W...THE 
SOUTHEASTERN GULF OF MEXICO...AND THE NORTHWESTERN CARIBBEAN SEA 
AND THE NORTH CENTRAL CARIBBEAN SEA. AN UPPER LEVEL RIDGE THAT
WAS IN BETWEEN THE TWO AREAS OF CYCLONIC FLOW IS BEING SQUEEZED 
ON BOTH SIDES AND IT HAS BECOME COMPARATIVELY NARROWER WITH TIME.

THE CARIBBEAN SEA...
A MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS ON TOP
OF THE YUCATAN PENINSULA...BELIZE...AND THE NORTHERN HALF OF 
GUATEMALA. BROAD UPPER LEVEL ANTICYCLONIC WIND FLOW ORIGINATES 
FROM PANAMA TO NICARAGUA...CURVING NORTHEASTWARD IN ORDER TO 
COVER JAMAICA AND SOUTHERN HAITI AND BARELY REACH THE 
SOUTHWESTERN DOMINICAN REPUBLIC. NUMEROUS STRONG SHOWERS AND 
THUNDERSTORMS ARE IN AN AREA OF UPPER LEVEL DIFFLUENT WIND FLOW 
FROM 14N TO 16N BETWEEN 81W AND 83W COVERING THE WATERS FROM 
JUST EAST OF NORTHEASTERN NICARAGUA TO EASTERN HONDURAS. BROAD 
MIDDLE TO UPPER LEVEL CYCLONIC FLOW ALSO COVERS THE NORTH CENTRAL
CARIBBEAN SEA. MIDDLE TO UPPER LEVEL TROUGH THAT HAS BEEN MOVING 
IN UNISON WITH THE 21N49W TO 8N54W TROPICAL WAVE EVENTUALLY 
EXTENDS INTO THE SOUTHEASTERN CORNER OF THE AREA.

THE ATLANTIC OCEAN...
A CYCLONIC CIRCULATION CENTER THAT IS ON TOP OF THE BAHAMAS HAS 
BECOME CUT-OFF FROM THE TROUGH THAT WAS EXTENDING FROM THE 
ATLANTIC OCEAN INTO THE CARIBBEAN SEA. ONE MIDDLE TO UPPER LEVEL 
CYCLONIC CIRCULATION CENTER IS NEAR 31N56W. A SECOND CYCLONIC 
CENTER IS NEAR 32N43W. SHOWERS ARE POSSIBLE IN BETWEEN THE
32N43W CYCLONIC CENTER AND THE BAHAMAS CUT-OFF CYCLONIC CENTER.
MIDDLE TO UPPER LEVEL DRY AIR IN SUBSIDENCE IS NORTH OF 10N WEST 
OF 30W. THE ONLY PRECIPITATION IN THE DRY AIR IS THAT WHICH IS
AROUND THE 21N49W 8N54W TROPICAL WAVE.

$$
MT