Atlantic Tropical Weather Discussion

000
AXNT20 KNHC 201047
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT SEP 20 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...
A TROPICAL WAVE IS ALONG 30W S OF 17N MOVING W NEAR 10 KT. THIS 
WAVE IS BENEATH AN UPPER LEVEL RIDGE AND NO CONVECTION IS NOTED 
WITH THIS FEATURE. 

A TROPICAL WAVE IS ALONG 52W S OF 19N MOVING W NEAR 10 KT. AN 
UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 14N57W E OF THE WAVE 
AXIS AND IS GENERATING SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION FROM 14N-19N BETWEEN 51W-60W.

A TROPICAL WAVE IS ALONG 65W S OF 19N MOVING W NEAR 5-10 KT. 
THIS WAVE IS EMBEDDED WITHIN A BROAD AREA OF LOW PRESSURE ACROSS 
THE ERN CARIBBEAN AND IS GENERATING A LARGE AREA OF CLOUDINESS 
WITH SCATTERED SHOWERS ACROSS THE LESSER ANTILLES. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS FROM 14N-16N BETWEEN 
63W-66W. SIMILAR CONVECTION IS FROM 9N-12N BETWEEN 62W-65W.

A TROPICAL WAVE IS ALONG 77W S OF 19N MOVING W NEAR 10-15 KT. 
SATELLITE IMAGERY INDICATES AN INVERTED-V SIGNATURE ACROSS THE 
WRN CARIBBEAN WITH SCATTERED MODERATE CONVECTION WITHIN 100 NM 
OF A LINE FROM THE WINDWARD PASSAGE NEAR 20N74W SW TO THE 
NICARAGUA AND COSTA RICA BORDER NEAR 11N84W.    

...THE ITCZ...
ITCZ AXIS IS ANALYZED ALONG 11N14W 6N20W 7N27W 8N32W 8N49W 9N54W 
11N64. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 
1N-9N BETWEEN 21W-27W. A SIMILAR AREA OF CONVECTION IS ACROSS 
THE SE CARIBBEAN SEA FROM 9N-12N BETWEEN 61W-64W.

...DISCUSSION...

GULF OF MEXICO...
UPPER LEVEL RIDGING IS ACROSS MUCH OF THE GULF THIS MORNING WITH 
WESTERLY UPPER FLOW DOMINATING FROM NRN MEXICO TO THE FLORIDA 
PENINSULA. A SURFACE TROUGH EXTENDS FROM 27N93W TO 22N97W ACROSS 
THE WRN GULF AND COVERS MUCH OF THE GULF WITH A BROAD AREA OF 
MULTILAYERED CLOUDINESS. EMBEDDED ISOLATED SHOWERS ARE POSSIBLE 
N OF 21N AND W OF 88W. WITH A DIFFLUENT PATTERN ALOFT IN PLACE 
ACROSS THE SW GULF...SCATTERED MODERATE TO STRONG CONVECTION IS 
ACROSS THE SRN BAY OF CAMPECHE AND SRN MEXICO FROM 16N-20N 
BETWEEN 90W-95W. A SURFACE RIDGE IS ACROSS THE SE CONUS AND 
EXTENDS WEAK RIDGING INTO THE NE GULF. AN AMPLE AMOUNT OF UPPER 
LEVEL MOISTURE IS NOTED OVER THE GULF REGION WHILE SUBSIDENCE 
AND DRY AIR IS ACROSS THE FLORIDA PENINSULA AND THE FAR NW GULF 
WATERS.

CARIBBEAN SEA...
TWO TROPICAL WAVES ARE ACROSS THE CARIBBEAN SEA...SEE THE 
TROPICAL WAVE SECTION FOR MORE DETAILS. WIDESPREAD CLOUDINESS 
AND SHOWERS ARE OVER PUERTO RICO AND THE LESSER ANTILLES WITH 
THE NEARBY TROPICAL WAVE ALONG 65W. CLUSTERS OF SCATTERED 
SHOWERS/TSTMS ARE ACROSS THE WRN CARIBBEAN FROM 10N-20N BETWEEN 
74W-83W IN ASSOCIATION WITH THE TROPICAL WAVE ALONG 75W...WHICH 
INCLUDES THE WINDWARD PASSAGE...ERN HISPANIOLA AND JAMAICA. AN 
UPPER LEVEL TROUGH EXTENDS FROM THE FAR W ATLC ACROSS CENTRAL 
CUBA INTO THE WRN CARIBBEAN TO NORTH OF PANAMA AND IS PROVIDING 
UPPER LEVEL DIFFLUENCE E OF 83W TO FURTHER ENHANCE THE SHOWER 
AND TSTM ACTIVITY. UPPER LEVEL RIDGING EXTENDS FROM THE SRN GULF 
OF MEXICO ACROSS THE NW CARIBBEAN W OF 83W PROVIDING UPPER LEVEL 
DIFFLUENCE TO INDUCE SCATTERED SHOWERS ACROSS THE GULF OF 
HONDURAS AND INLAND CENTRAL AMERICA. SIMILAR SCATTERED SHOWERS 
AND TSTMS ARE ACROSS THE SW CARIBBEAN S OF 13N BETWEEN 74W-84W 
DUE TO THE CLOSE PROXIMITY OF THE ITCZ. MODERATE TRADE WINDS ARE 
NOTED ACROSS THE BASIN THIS MORNING.

ATLANTIC OCEAN...
A SURFACE TROUGH EXTENDS SW FROM A 1014 MB LOW CENTERED NEAR 
32N73W TO THE CENTRAL BAHAMAS NEAR 24N77W. SCATTERED SHOWERS ARE 
WITHIN 90 NM EAST OF THE TROUGH. THIS ACTIVITY IS BEING ENHANCED 
BY SOUTHWESTERLY FLOW AND UPPER LEVEL DIFFLUENCE EAST OF AN 
UPPER LEVEL TROUGH ALONG THE ERN SEABOARD OF THE US. THIS UPPER 
TROUGH DIGS INTO THE CARIBBEAN SEA ACROSS ERN CUBA. FARTHER 
EAST...A BROAD UPPER-LEVEL LOW IS SPINNING OVER THE CENTRAL ATLC 
NEAR 26N46W. AN UPPER LEVEL HIGH CENTERED OVER THE CAPE VERDE 
ISLANDS NEAR 17N25W EXTENDS W TO 38W ENVELOPING MUCH OF THE ERN 
ATLC. AT THE SURFACE...A RIDGE OF HIGH PRESSURE COVERS THE 
DISCUSSION AREA N OF 20N AND E OF 65W ANCHORED ON A SERIES OF 
SURFACE HIGHS CENTERED N OF THE REGION.

$$
HUFFMAN