[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 171106
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST FRI JAN 17 2009

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
1030 UTC.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 6N10W 3N20W 2N30W 1N40W AND INTO
NE BRAZIL NEAR THE EQUATOR AND 49W. THE ITCZ IS QUITE ACTIVE
THIS MORNING WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION
ALONG THE AXIS FROM 1N-5N BETWEEN THE COAST OF AFRICA AND 30W.
AN ADDITIONAL CLUSTER OF MODERATE CONVECTION IS WITHIN 50 NM OF
THE AXIS BETWEEN 38W-42W.

...DISCUSSION...

THE GULF OF MEXICO...
A 1036 MB HIGH OVER THE SOUTHEAST CONUS EXTENDS A RIDGE OVER
FLORIDA AND THE ENTIRE GULF MAINTAINING BELOW AVERAGE
TEMPERATURES. WINDS IN THE NW GULF HAVE TURNED SOUTHERLY AND
WEAKENED TO 15 KT IN RESPONSE TO THIS RIDGE BEGINNING TO SHIFT
EASTWARD. NE WINDS 15-20 KT FLOW ACROSS THE REMAINDER OF THE
BASIN. A COLD FRONT IS EXPECTED TO FOLLOW THE RIDGE...ENTERING
THE NW GULF ON SUN. SWLY FLOW ALOFT IS ADVECTING HIGH CLOUDS
OVER THE SW CARIBBEAN AND FAIR WEATHER STRATOCUMULUS CLOUDS ARE
NOTED IN THE CENTRAL GULF. ELSEWHERE...MOSTLY CLEAR SKIES
PERSIST IN THE DRY AIR MASS.

THE CARIBBEAN SEA...
A STATIONARY FRONT LINGERS IN THE NW CARIBBEAN...GENERATING
SCATTERED SHOWERS IN THE VICINITY. AS OF 0900 UTC...THE FRONT
ENTERS THE BASIN OVER CENTRAL CUBA AND EXTENDS ACROSS THE CAYMAN
ISLANDS TO NEAR 16N84W. NE WINDS 20-25 KT COVER THE NW CARIBBEAN
BEHIND THE FRONT. THIS BOUNDARY IS EXPECTED TO MOVE SLOWLY
EASTWARD BEFORE BECOMING DIFFUSE ON SUN. A SFC TROUGH LIES OVER
THE EASTERN CARIBBEAN FROM THE EASTERN TIP OF PUERTO RICO TO
NEAR 12N66W. BROAD CIRCULATION SURROUNDING THIS TROUGH IS
EVIDENT ON SATELLITE IMAGERY. SAN JUAN DOPPLER RADAR SHOWS
SCATTERED SHOWERS MOVING ACROSS THE VIRGIN ISLANDS AND PUERTO
RICO. ADDITIONAL SHOWERS ARE OVER THE E CARIBBEAN WATERS N OF
14N BETWEEN 64W-70W. THIS TROUGH IS EXPECTED TO BECOME DIFFUSE
OVER THE CENTRAL CARIBBEAN NEAR 75W ON MON. STRONG SUBSIDENCE
AND DRY AIR ALOFT PREVENT CONVECTION IN THE CENTRAL CARIBBEAN.
MODERATE TO STRONG TRADE WINDS PERSIST ACROSS THE BASIN.

THE ATLANTIC OCEAN...
A DEEP-LAYER TROUGH OVER THE EASTERN SEABOARD SUPPORTS A FRONTAL
BOUNDARY ACROSS THE W ATLC. THE STATIONARY FRONT ENTERS THE
DISCUSSION AREA NEAR 30N62W AND EXTENDS ACROSS THE BAHAMAS AND
OVER CENTRAL CUBA INTO THE CARIBBEAN. MULTI-LAYER CLOUDS AND
SCATTERED SHOWERS FILL IN THE W ATLC BEHIND THE FRONT. FARTHER
SOUTH...A SFC TROUGH EXTENDS FROM 22N64W SOUTHWARD ACROSS PUERTO
RICO AND INTO THE CARIBBEAN. SCATTERED SHOWERS ASSOCIATED WITH
THE TROUGH ARE SOUTH OF 24N BETWEEN 58W-68W. A STRONG SFC RIDGE
ANCHORED ON A 1033 MB HIGH NEAR 32N33W COVERS THE REMAINDER OF
THE ATLC. ALOFT...A DIFFLUENT PATTERN IN THE TROPICS IS
ENHANCING CONVECTION AROUND THE ITCZ.

$$
WADDINGTON







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