000
AXNT20 KNHC 041035
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI MAY 04 2007

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...METEOROLOGICAL ANALYSIS... 
WEATHER OBSERVATIONS...AND RADAR.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1015 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N8W 3N11W 2N18W 3N40W 5N52W. 
SCATTERED MODERATE/STRONG CONVECTION IS FROM 5N TO JUST S OF THE 
EQUATOR BETWEEN THE PRIME MERIDIAN AND 8W. CLUSTERS OF SIMILAR 
CONVECTION ARE FROM 1N-6N BETWEEN 9W-14W. SCATTERED MODERATE/ 
ISOLATED STRONG CONVECTION IS WITHIN 120 NM OF THE AXIS FROM 
440W TO 55W INCLUDING THE COAST OF SOUTH AMERICA. 

...DISCUSSION...

GULF OF MEXICO...
THE STRONG UPPER LOW IS MOVING FROM NE ACROSS ARKANSAS 
GENERATING STRONG THUNDERSTORMS N OF 28N TO INLAND OVER SE 
LOUISIANA AND MISSISSIPPI BETWEEN 88W-91W. THE W GULF IS 
DOMINATED BY A STRONG UPPER RIDGE THAT EXTENDS FROM THE E 
PACIFIC REGION ACROSS MEXICO TO THE N GULF COAST NEAR THE 
TEXAS/LOUISIANA BORDER AND IS PUSHING THE THUNDERSTORMS 
EASTWARD. THE UPPER TROUGH REMAINS OVER THE E GULF ACROSS 
FLORIDA INTO THE W ATLC AND S INTO THE W CARIBBEAN. AS LAST 
NIGHT...STILL NO ASSOCIATED SURFACE REFLECTION. WEAK PRESSURE 
GRADIENT IS ACROSS THE GULF AND WITH THE DRY AIR IN PLACE THE 
REMAINDER OF THE GULF CLEAR SKIES AGAIN THIS MORNING. 

CARIBBEAN SEA...
THE UPPER TROUGH IN THE E GULF OF MEXICO COVERS THE W CARIBBEAN 
TO CENTRAL AMERICA N OF 15N W OF 74W. BROAD UPPER RIDGE 
DOMINATES THE REMAINDER OF THE CARIBBEAN ANCHORED OVER E 
VENEZUELA. THIS UPPER RIDGE IS ADVECTING TROPICAL MOISTURE N 
ACROSS THE CENTRAL CARIBBEAN BETWEEN 67W-80W WITH POSSIBLE 
ISOLATED SHOWERS. THE ITCZ AXIS IN THE E PACIFIC REGION REMAINS 
OVER PANAMA AND COSTA RICA GENERATING SCATTERED SHOWERS/ 
THUNDERSTORMS S OF 14N W OF 75W TO INLAND OVER CENTRAL AMERICA. 
OTHERWISE THE W AND E CARIBBEAN REMAIN DRY WITH CLEAR SKIES AND 
MODERATE EASTERLY TRADE WINDS USHERING IN SOME LOW LEVEL 
ISOLATED SHOWERS OVER THE NE CARIBBEAN N OF 16N E OF 76W.  

ATLANTIC...
UPPER TROUGH OVER THE E GULF OF MEXICO EXTENDS ACROSS FLORIDA 
INTO THE W ATLC W OF 70W. A REMNANT SURFACE TROUGH REMAINS ALONG 
74W FROM 21N-32W WITH A DEVELOPING LOW LEVEL CENTER NEAR 
30N74W. THE UPPER RIDGE FROM THE CARIBBEAN EXTENDS OVER THE 
REMAINDER OF THE W ATLC ALONG 60W ENHANCING CLUSTERS OF 
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS BETWEEN 32N TO THE N 
COAST OF THE GREATER ANTILLES BETWEEN 67W AND THE SURFACE TROUGH 
WITH SOME ISOLATED THUNDERSTORMS BETWEEN THE SURFACE TROUGH AND 
80W. THE REMAINDER OF THE ATLC IS UNDER BENIGN UPPER LEVEL 
TROUGH-RIDGE-TROUGH PRODUCING NO SIGNIFICANT WEATHER. BROAD 
SURFACE RIDGE COVERS THE ATLC E OF 70W ANCHORED BY A 1028 MB 
HIGH S OF THE AZORES NEAR 35N30W. THIS SURFACE RIDGE COUPLED 
WITH THE DRY AIR IN PLACE IS GIVING THE REMINDER OF THE ATLC 
FAIR WEATHER AGAIN THIS MORNING. 

$$
WALLACE