000
AXNT20 KNHC 181729
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN MAY 18 2008

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
WWWW UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 38W S OF 10N MOVING W 10-15 KT. A WEAK 
INVERTED-V SIGNATURE IS OBSERVED ON VISIBLE SATELLITE IMAGERY. 
CONVECTIVE ACTIVITY NEAR THE WAVE IS ASSOCIATED WITH THE ITCZ. 

TROPICAL WAVE IS ALONG 60W S OF 10N MOVING W 10 KT. WAVE 
SIGNATURE REMAINS DISTORTED AS IT CONTINUES ACROSS SOUTH 
AMERICA. THUS...THE POSITION IS LARGELY BASED ON CONTINUITY. A 
CLUSTER OF SCATTERED MODERATE CONVECTION IS FROM 5N-7N BETWEEN 
58W-61W. 

TROPICAL WAVE HAS MOVED OUT OF THE SW CARIBBEAN AND IS NOW 
CENTERED ALONG 83W IN THE E PACIFIC. 

..THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 5N7W 3N20W 4N30W 5N40W AND INTO NE 
BRAZIL NEAR 2N51W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION 
IS N OF THE EQUATOR TO THE AFRICAN COAST EAST OF 9W TO THE PRIME 
MERIDIAN. CLUSTERS OF MODERATE CONVECTION ARE WITHIN 120 NM S OF 
THE AXIS BETWEEN 18W-24W. CLUSTERS OF SCATTERED MODERATE TO 
STRONG CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN 45W AND 
THE COAST OF S AMERICA. 

...DISCUSSION...

GULF OF MEXICO...
A DISSIPATING FRONTAL BOUNDARY REMAINS STRETCHED ACROSS THE GULF 
ENTERING THE REGION NEAR TAMPA BAY AND CONTINUING ALONG 26N90W 
TO THE BAY OF CAMPECHE AND OVER THE MEXICAN COAST NEAR VERACRUZ. 
VISIBLE SATELLITE IMAGERY...DOPPLER RADAR MOSAIC...AND LIGHTNING 
DATA INDICATE A SWATH OF SCATTERED SHOWERS AND THUNDERSTORMS UP 
TO 200 NM BEHIND THE BOUNDARY MOVING QUICKLY TOWARD THE NE IN 
SWLY UPPER FLOW. THIS CONVECTION IS BEING ENHANCED BY 
INSTABILITY ALONG A SHORTWAVE TROUGH OVER THE LOWER MISSISSIPPI 
RIVER VALLEY. AHEAD OF THE BOUNDARY...THE GULF IS MOSTLY CLEAR 
DUE TO MODERATE SUBSIDENCE AROUND AN UPPER RIDGE. EXPECT THE 
FRONT TO COMPLETELY DISSIPATE TONIGHT WITH WEAK HIGH PRESSURE 
BUILDING IN ITS WAKE.

CARIBBEAN SEA...
ISOLATED SHOWERS AND THUNDERSTORMS...REMNANTS OF A DISSIPATED 
SFC TROUGH...REMAIN IN THE CARIBBEAN N OF 17N. MODERATE EASTERLY 
TRADE WINDS DOMINATE THE WEATHER PATTERN ACROSS THE REMAINDER OF 
THE CARIBBEAN...WITH THE ONLY SIGNIFICANT CONVECTION FOUND IN 
THE FAR SW CARIBBEAN ALONG THE COASTS OF PANAMA AND COSTA RICA 
S OF 11N. THIS ACTIVITY IS ASSOCIATED WITH A TROPICAL WAVE IN 
THE E PACIFIC ALONG 83W. ELSEWHERE...DEEP CONVECTION IS LIMITED 
UNDER STRONG SUBSIDENCE AND DRY STABLE AIR AROUND AN UPPER HIGH 
NEAR JAMAICA.

ATLANTIC OCEAN...
A WEAK COLD FRONT ENTERS THE DISCUSSION AREA NEAR 31N64W AND 
CONTINUES ALONG 29N70W TO THE CENTRAL FLORIDA COAST NEAR 28N80W 
WHERE IT BEGINS TO DISSIPATE ACROSS THE GULF. LOW-LEVEL CLOUDS 
AND SCATTERED SHOWERS ARE WITHIN 100 NM AHEAD OF THE FRONT N OF 
28N. A CLUSTER OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS 
IS IN THE W ATLC FROM 29N-31N BETWEEN 72W-76W. FARTHER EAST...A 
DISSIPATING COLD FRONT ENTERS THE REGION NEAR 31N43W AND 
CONTINUES ALONG 24N50W TO 20N58W. A NARROW BAND OF LOW-LEVEL 
CLOUDS...WITH NO INDICATION OF PRECIPITATION...SURROUNDS THE 
FRONT. A WEAK SFC HIGH CENTERED NEAR 25N56W IS EMBEDDED IN A 
MUCH LARGER SFC RIDGE THAT ENCOMPASSES THE CENTRAL AND EAST ATLC.

$$
WADDINGTON