[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 151144
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT SEP 15 2012

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1115 UTC.

...SPECIAL FEATURES...

HURRICANE NADINE IS CENTERED NEAR 30.7N 51.4W 15/0900 UTC OR
ABOUT ABOUT 690 NM E OF BERMUDA...AND ABOUT 1280 NM WSW OF THE
AZORES. NADINE IS MOVING NE AT 13 KT. ESTIMATED MINIMUM CENTRAL
PRESSURE IS 985 MB. MAXIMUM SUSTAINED WIND SPEED IS 65 KT WITH
GUSTS TO 80 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO
HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. NUMEROUS STRONG
CONVECTION IS FROM 30N-32N BETWEEN 49W-52W. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS ELSEWHERE FROM 27N-34N
BETWEEN 46W-53W.

...TROPICAL WAVES...

TROPICAL WAVE MOVES MOVES CLOSER TO THE LESSER ANTILLES WITH
AXIS ALONG 15N52W TO 9N49W MOVING W NEAR 15 KT. THE WAVE LIES
WITHIN AN AREA OF MAXIMUM MOISTURE EVIDENT IN TOTAL PRECIPITABLE
WATER IMAGERY. AN EARLIER ASCAT SCATTEROMETER PASS ALSO
INDICATED THAT LOW-LEVEL CYCLONIC FLOW IS PRESENT AROUND THE
WAVE AXIS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM
10N-16N BETWEEN 46W-56W.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE COAST OF
SENEGAL AT 14N17W CONTINUING OVER ATLC WATERS ALONG 10N23W
8N34W. THE ITCZ EXTENDS FROM 8N34W TO 9N42W. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS FROM 8N-11N BETWEEN
23W-26W...AND FROM 7N-10N BETWEEN 29W-31W.

...DISCUSSION...

GULF OF MEXICO...
A FEW SHOWERS/THUNDERSTORMS ARE ACROSS THE GULF OF MEXICO THIS
MORNING. RADAR IMAGERY CONTINUES TO SHOW SHOWERS/THUNDERSTORMS
ALONG THE TEXAS COAST ASSOCIATED WITH A STATIONARY FRONT THAT
PARALLELS THE COASTLINE. SOME ISOLATED SHOWERS/THUNDERSTORMS ARE
ALSO OVER THE EASTERN GULF AND THE FLORIDA STRAITS ASSOCIATED
WITH A SURFACE TROUGH ALONG 28N85W TO 24N84W. SOME OF THIS
ACTIVITY IS ALSO SUPPORTED BY DIFFLUENCE ALOFT AROUND AN UPPER
LEVEL TROUGH EXTENDING FROM THE FLORIDA PANHANDLE TO THE SW
GULF. SCATTERED SHOWERS/THUNDERSTORMS ARE ALSO PRESENT IN THE
CENTRAL GULF FROM 25N-26N BETWEEN 89W-92W ASSOCIATED WITH A
SECOND SURFACE TROUGH ALONG 26N91W TO 22N89W. SCATTERED
SHOWERS/THUNDERSTORMS ALSO CONTINUE ALONG THE MEXICO COAST IN
THE SW GULF. THIS ACTIVITY IS LIKELY TIED TO THE UPPER TROUGH AS
WELL. MOIST CONDITIONS ARE EXPECTED TO REMAIN ACROSS THE BASIN
FOR AT LEAST THE NEXT 24 HOURS AS THE UPPER TROUGH REMAINS OVER
THE BASIN.

CARIBBEAN SEA...
THE CARIBBEAN REMAINS MOSTLY CALM THIS MORNING WITH CLEAR SKIES
COVERING THE MAJORITY OF THE AREA. THIS FAIR WEATHER IS RELATED
TO DRY AIR ALOFT AROUND AN UPPER LEVEL RIDGE COVERING THE ENTIRE
CENTRAL AND WESTERN CARIBBEAN. A FEW SHOWERS/THUNDERSTORMS HAVE
POPPED UP OVER CENTRAL AMERICA INCLUDING NICARAGUA...COSTA
RICA...AND PANAMA. MOST OF THIS ACTIVITY IS TIED TO THE MONSOON
TROUGH AXIS EXTENDING FROM THE E PACIFIC THROUGH PANAMA TO
NORTHERN COLOMBIA. A VERY NARROW UPPER TROUGH IS OVER THE
EASTERN CARIBBEAN EXTENDING FROM PUERTO RICO TO VENEZUELA...BUT
IT IS EMBEDDED WITH DRY AIR PREVENTING IT FROM CAUSING ANY
ACTIVE WEATHER AT THIS TIME. TRADEWIND FLOW OF 10-15 KT IS
PRESENT ACROSS THE AREA WITH SOME STRONGER WINDS NORTH OF
COLOMBIA. EXPECT SHOWERS/THUNDERSTORMS ACROSS THE SW CARIBBEAN
AND CENTRAL AMERICA DURING THE DAYTIME HOURS WITH LITTLE
CHANGE ELSEWHERE OVER THE NEXT 24 HOURS.

ATLANTIC OCEAN...
AN UPPER LEVEL RIDGE COVERS THE MAJORITY OF THE SW NORTH
ATLANTIC THIS MORNING PROVIDING MOSTLY FAIR CONDITIONS BESIDES
A FEW SHOWERS/THUNDERSTORMS THAT HAVE FORMED ALONG THE EAST
COAST OF FLORIDA AND ACROSS THE FLORIDA STRAITS. A NARROW
UPPER LEVEL TROUGH EXTENDS FROM 34N63W TO PUERTO RICO
SUPPORTING A WEAK SURFACE TROUGH...REMNANTS OF AN OLD FRONTAL
BOUNDARY...ALONG 31N68W 27N69W 24N72W. POSSIBLE ISOLATED SHOWERS
ARE WITHIN 150 NM E OF THE AXIS. TO THE E...HURRICANE NADINE
DOMINATES THE CENTRAL ATLC. SEE SPECIAL FEATURES ABOVE FOR MORE
DETAILS. A WEAK SURFACE HIGH IS E OF NADINE CENTERED NEAR
27N42W. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED
SOUTH OF NADINE NEAR 23N50W. THE UPPER RIDGE ALONG WITH THE
SURFACE RIDGE ARE PROVIDING FAIR CONDITIONS ACROSS THE REMAINDER
OF THE CENTRAL AND EASTERN ATLC. AN UPPER LEVEL TROUGH COVERS
THE EASTERN ATLC EXTENDING FROM THE AZORES ISLANDS TO NEAR
29N21W 16N38W...BUT IS NOT CAUSING ANY ACTIVE WEATHER IN THE
DISCUSSION AREA. THE FIRST VISIBLE SATELLITE IMAGES OF THE DAY
ALONG WITH GOES-R ENHANCED IMAGERY INDICATE THAT AN AREA OF
SAHARAN DUST EXTENDS S OF 20N FROM THE COAST OF AFRICA TO NEAR
45W.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
WALTON





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