[Tropical] Tropical Weather Discussion

[Nashville EMWIN]

AXNT20 KNHC 091215
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT THU 09 SEP 2004

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN
SECTIONS OF SOUTH 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 0600 UTC SURFACE ANALYSIS AND
SATELLITE IMAGERY THROUGH 1045 UTC.

...SPECIAL FEATURE...

HURRICANE IVAN HAS REACHED THE CATEGORY 5 LEVEL ON THE
SAFFIR-SIMPSON SCALE. IT IS HEADING IN THE GENERAL DIRECTION
OF JAMAICA.

THE CENTER OF HURRICANE IVAN...AT 09/1200 UTC...WAS NEAR 14.2N
70.7W...OR ABOUT 455 MILES/735 KM...SE OF KINGSTON JAMAICA.
MAXIMUM SUSTAINED WIND SPEED 160 KT WITH HIGHER GUSTS.
ESTIMATED MINIMUM CENTRAL PRESSURE 919 MB. SEE LATEST NHC PUBLIC
ADVISORY OR NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCPAT4/WTNT34 KNHC OR MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS.
NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE CONCENTRATED
AROUND THE CIRCULATION CENTER FROM 13N TO 15N BETWEEN 69W AND
71W. SCATTERED MODERATE TO STRONG SHOWERS AND THUNDERSTORMS ARE
ELSEWHERE AROUND THE CENTER FROM 12N TO 18N BETWEEN 67W AND 73W.
THE EYE IS CLEARLY DEFINED. IT IS LOCATED EAST OF A WELL-DEFINED
UPPER-LEVEL WEST CENTRAL CARIBBEAN SEA CYCLONIC CIRCULATION
CENTER. THE CYCLONIC CENTER IS EXPECTED
TO MOVE WESTWARD IN TANDEM WITH IVAN DURING THE NEXT FEW DAYS.
IVAN SHOULD REMAIN A VERY DANGEROUS HURRICANE AS IT MARCHES
WEST-NORTHWESTWARD THROUGH THE CENTRAL CARIBBEAN SEA. THE
UPPER-LEVEL OUTFLOW PATTERN IS IMPRESSIVE AND
WELL-ESTABLISHED...AND IF ANYTHING...WILL ONLY GET BETTER
FOR THE NEXT 72 TO 96 HOURS. THEREFORE...THE FUTURE INTENSITY
WILL LIKELY BE MODULATED BY INNER-CORE CONVECTIVE CHANGES AND
LAND INTERACTION SINCE TH WATER AHEAD OF IVAN IS ONLY FORECAST
TO GET WARMER...AS WARM AS 30C SOUTH OF CUBA AND OVER THE
FLORIDA STRAITS.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 30W SOUTH OF 17N MOVING WEST 10 TO 15 KT.
ISOLATED MODERATE TO LOCALLY STRONG SHOWERS AND THUNDERSTORMS
FROM 9N TO 11N BETWEEN 27W AND 34W.

TROPICAL WAVE ALONG 46W/47W SOUTH OF 18N MOVING WEST 15 KT.
ISOLATED MODERATE TO LOCALLY STRONG SHOWERS AND THUNDERSTORMS
FROM 15N TO 24N BETWEEN 44W AND 49W.

TROPICAL WAVE MOVING INTO THE ISTHMUS OF TEHUANTEPEC ALONG 94W
SOUTH OF 20N...MOVING WEST 10 TO 15 KT. SCATTERED STRONG SHOWERS
AND THUNDERSTORMS IN THE SOUTHWESTERN GULF OF MEXICO AND THE
ISTHMUS OF TEHUANTEPEC FROM 17.5N TO 19N BETWEEN 94W AND 96W.
MORE NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE IN THE
EASTERN PACIFIC OCEAN FROM 13N TO 14.5N BETWEEN 95.5W AND 99W.

...ITCZ...
ITCZ 13N17W 9N29W 9N44W TO TRINIDAD NEAR 11N61W...AND IN THE
SOUTHWESTERN CARIBBEAN SEA ALONG 10N75W 9N83W. NUMEROUS STRONG
SHOWERS AND THUNDERSTORMS FROM 6N TO 7.5N BETWEEN 38W AND 41W.
CELLS OF SHOWERS AND THUNDERSTORMS ARE IN THE COASTAL AREAS OF
COLOMBIA FROM 10N TO 12N BETWEEN 75W AND 77W. WIDELY SCATTERED
TO SCATTERED MODERATE/ISOLATED STRONG SHOWERS AND THUNDERSTORMS
FROM 4N TO 8N BETWEEN 10W AND 20...AND FROM 9N TO 11N BETWEEN
27W AND 38W. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS AREA
APPROACHING THE AFRICA COAST FROM 12N TO 14N BETWEEN 15W AND 17W.

...DISCUSSION...

GULF OF MEXICO...
NEARLY STATIONARY MID/UPPER LEVEL TROUGH REMAINS OVER THE
CENTRAL GLFMEX EXTENDING SWD FROM T.D FRANCES NOW OVER THE
EASTERN UNITED STATES TO THE BAY OF CAMPECHE. STRONG SUBSIDENCE
AND DRY AIR IN THE WESTERN FLANK OF THE TROUGH SUPPRESSING
SHOWERS AND THUNDERSTORMS...SAVE A SMALL AREA IN THE SOUTHWESTERN
CORNER. DISSIPATING STATIONARY FRONT FROM NORTHEASTERN CORNER OF
AREA...TO THE NORTH CENTRAL PART...TO 25N96W IN THE WEST CENTRAL
GULF WATERS. THE MID-UPPER RIDGE CURRENTLY OVER FLORIDA WILL
BUILD WESTWARD PROVIDING AN IDEAL ENVIRONMENT FOR THE FORMATION
OF CLOUDINESS AND SHOWERS/THUNDERSTORMS. MAIN BAND OF ACTIVITY
IS EXPECTED TO EXTEND FROM CENTRAL FLORIDA TO THE COAST OF
MEXICO NEAR TAMPICO BY FRI MORNING. A SURFACE TROUGH RUNS FROM
26N84W TO 23N87W TO 20N90W IN THE YUCATAN PENINSULA.

CARIBBEAN SEA...
THE BIGGEST SHOW IN TOWN IS HURRICANE IVAN. THE MID-OCEANIC
TROUGH AND ASSOCIATED FRONTAL BOUNDARY CONTINUE TO CREATE
A WEAKNESS WITHIN THE LOW-LEVEL SUBTROPICAL RIDGE OVER THE
CENTRAL ATLC.

SUBTROPICAL ATLANTIC...
A LARGE SCALE RIDGE-TROUGH-RIDGE PATTERN DOMINATES MOST OF THE
SUBTROPICAL ATLC WITH A STRONG MID-UPPER LEVEL RIDGE OVER THE
WESTERN ATLANTIC OCEAN FROM FLORIDA NEWD ALONG THE UNITED STATES
EAST COAST...MID-OCEANIC TROUGH EXTENDING FROM 35N45W SOUTHWARD
TO THE S BAHAMAS...AND RIDGE OVER THE E ATLC E OF 40W.  ASIDE
FROM CONVECTION OVER FLORIDA...THE BULK OF THE ACTIVITY IS
FOCUSED OVER THE CENTRAL ATLC WHERE UPPER DYNAMICS ASSOCIATED
WITH THE MID-OCEANIC TROUGH IS TRIGGERING SHOWERS/THUNDERSTORMS
NORTH OF 31N63W 23N55W BEYOND 29N38W. BROAD SURFACE ANTICYCLONIC
FLOW IS NORTH OF 20N ON EITHER SIDE THE SURFACE TROUGH. THE
GENERAL UPPER LEVEL PATTERN CURRENTLY IN PLACE WILL REMAIN OVER
THE SUBTROPICAL ATLC DURING NEXT COUPLE OF DAYS WITH THE
TRAILING END OF THE MID-OCEANIC TROUGH GRADUALLY RETROGRADING
WEST AS AN UPPER LOW FORMS NEAR 25N55W AND BECOMES CUT OFF.

TROPICAL ATLANTIC...
UPPER LEVEL TROUGH IS DIGGING SWD OVER THE CAPE VERDE ISLANDS
WITH ASSOCIATED SUBSIDENCE AND DRY AIR COVERING MUCH OF THE AREA
E OF 35W. MID-UPPER LEVEL RIDGE BETWEEN 35W-50W IS PRODUCING
DEEP EASTERLY FLOW...A GENERALLY FAVORABLE ENVIRONMENT FOR
ITCZ/TROPICAL WAVE CONVECTION. FURTHER W...A WEAK MID-UPPER
LEVEL TROUGH ALONG 52W IS PRODUCING STRONG SUBSIDENCE TO ITS
WEST SUPPRESSING ITCZ ACTIVITY AS IT MOVES SLOWLY WEST.

$$
MT


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