[Tropical] Tropical Weather Discussion

[Nashville EMWIN]

AXNT20 KNHC 040507
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT 04 SEP 2004

TROPICAL WEATHER DISCUSSION FOR N AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN  SECTIONS
OF S AMERICA...AND ATLC 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0430 UTC.

...SPECIAL FEATURES...

HURRICANE FRANCES IS CENTERED NEAR 26.1N 77.8 W AT 04/0300 UTC
MOVING WEST NORTHWEST AT 5 KT. MAXIMUM SUSTAINED WIND SPEED IS
90 KT WITH GUSTS TO 110 KT. MINIMUM CENTRAL PRESSURE IS 960 MB.
SEE LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS
MIATCPAT1/WTNT31 KNHC AND THE FORECAST/ADVISORY UNDER HEADERS
MIATCMAT1/WTNT21 KNHC FOR ADDITIONAL INFORMATION. FRANCES
CONTINUES TO WEAKENED SLIGHTLY WITH LESS CONVECTION IN FEEDER
BANDS ESPECIALLY TO THE W OF THE SYSTEM. THE WIND FIELD HAS
BROADENED OVER A GREATER AREA. FRANCES IS NOW A STRONG CAT 2
HURRICANE. OUTFLOW IS MOST PRONOUNCED IN THE EAST SEMICIRCLE DUE
TO WESTERLY SHEAR ALOFT. DRY SUBSIDENCE IS ALSO NOTED ON WATER
VAPOR IMAGERY W OF THE CENTER OVER FLORIDA AND THE EASTERN GULF
OF MEXICO. SCATTERED STRONG CONVECTION IS WITHIN 120 NM IN THE
NE SEMICIRCLE. SCATTERED MODERATE CONVECTION EXTENDS FROM
23N-29N BETWEEN 73W-79W.

TROPICAL STORM IVAN IS CENTERED NEAR 9.1N 35.8W AT 04/0300 UTC
MOVING W AT 15 KT. THE MAXIMUM SUSTAINED WIND SPEED IS 45 KT
WITH GUSTS TO 55 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 999
MB. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. UPPER LEVEL CONDITIONS
WILL REMAIN FAVORABLE FOR CONTINUED STRENGTHENING OF IVAN TO
HURRICANE STATUS IN 36 TO 48 HOURS. NUMEROUS STRONG CONVECTION
WITHIN 60 NM OF THE CENTER IN THE S SEMICIRCLE. SCATTERED
MODERATE/STRONG CONVECTION COVERS THE AREA FROM 6N-10N BETWEEN
34W-40W.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 68W/69W S OF 20N MOVING W 10-15 KT. WAVE
AXIS IS DIFFICULT TO LOCATE DUE TO UPPER LEVEL CLOUDS. CLUSTERS
OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE OVER THE E
CARIBBEAN N OF 13N E OF 67W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 9N10W 11N25W 8N44W 11N62W. OTHER
THAN T.S. IVAN...SCATTERED MODERATE CONVECTION IS WITHIN 75 NM
OF 8N FROM 21W-27W.

...DISCUSSION...

GULF OF MEXICO...
WEAK MID/UPPER LOW IN THE W GULF CENTERED NEAR 22N95W PREVENTING
THE AFTERNOON THUNDERSTORMS OVER E MEXICO FROM ENTERING THE W
GULF. MID/UPPER LEVEL RIDGE AXIS EXTENDS FROM E TEXAS NEAR
28N98W NE ALONG 31N90W THEN N ACROSS CENTRAL ALABAMA BEYOND
32N87W. BROAD UPPER SUBSIDENCE COVERS THE E GULF AND FLORIDA
BETWEEN 81W-87W...BUT IS ERODING ALONG THE EASTERN EDGE WITH THE
APPROACH OF THE MOISTURE PLUME ASSOCIATED WITH HURRICANE FRANCES
ESPECIALLY OVER NE FLORIDA. AT THE SURFACE...EXTENDS FROM S
MISSISSIPPI ACROSS N ALABAMA INTO NW GEORGIA.

W ATLANTIC AND CARIBBEAN...
UPPER LEVEL HIGH CONTINUES JUST SW OF HURRICANE FRANCES NEAR
24N81W WITH BROAD FLOW COVERING THE W ATLC INTO THE CENTRAL/
WESTERN CARIBBEAN W OF 66W. THIS IS CONTRIBUTING TO THE WLY
SHEAR THAT FRANCES IS EXPERIENCING. STRONG UPPER SUBSIDENCE IS
SUPPRESSING SHOWERS AND THUNDERSTORMS. MID/UPPER LEVEL LOW IS
OVER THE WINDWARD ISLANDS NEAR 13N61W WITH FLOW COVERING THE E
CARIBBEAN AND W TROPICAL ATLC FROM 12N-20N BETWEEN 56W-66W.

REMAINDER OF SUBTROPICAL ATLANTIC...
SMALL WEAK UPPER LEVEL LOW IS IN THE CENTRAL ATLC ABOUT 750 NM
SE OF BERMUDA NEAR 26N52W EMBEDDED WITH MID/UPPER LEVEL STRONG
SUBSIDENCE THAT COVERS THE AREA FROM 22N-30N BETWEEN 50W-62W. AN
UPPER LEVEL HIGH IS CENTERED NEAR 22N40W WITH RIDGE AMPLIFYING
NE BEYOND 32N36W. SURFACE 1012 MB LOW IS CENTERED NEAR 21N45W.
ASSOCIATED UPPER DIFFLUENCE IS ENHANCING SCATTERED MODERATE/
STRONG CONVECTION NE OF THE SURFACE LOW WITHIN 120 NM OF LINE
FROM 24N45W-28N40W. IN THE FAR E ATLC...AN UPPER LEVEL TROUGH
EXTENDS THROUGH 32N13W SW TO 17N26W. MID/UPPER LEVEL MODERATE/
STRONG SUBSIDENCE COVERS THE AREA WITHIN 375 NM OF LINE FROM
13N17W-12N32W.

TROPICAL ATLC...
UPPER DIFFLUENCE IS ENHANCING CLUSTERS OF SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS FROM 10N-19N BETWEEN 51W-62W INCLUDING
THE LESSER ANTILLES.

$$
WALLACE


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