[Tropical] Tropical Weather Discussion

[EMWIN Server]

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




This weather bulletin was brought to you by:
www.nashvilleweather.net