[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 292341
TWDAT

TROPICAL WEATHER DISCUSSION
NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SUN SEP 29 2013

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURE...

TROPICAL DEPRESSION ELEVEN IS CENTERED NEAR 27.2N 47.6W AT
29/2100 UTC OR ABOUT 1012 NM NE OF THE NORTHERN LEEWARD
ISLANDS... OR ABOUT 947 NM ESE OF BERMUDA MOVING NE AT 8 KT.
ESTIMATED MINIMUM CENTRAL PRESSURE IS 1010 MB. MAXIMUM SUSTAIN
WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. PLEASE SEE LATEST NHC
PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 KNHC
AND THE FULL ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21
KNHC FOR MORE DETAILS. SCATTERED MODERATE TO STRONG CONVECTION
IS NE OF THE LOW PRESSURE CENTER FROM 26N-30N BETWEEN 45W-49W.

...TROPICAL WAVES...

A TROPICAL WAVE AXIS EXTENDS WEST OF THE CAPE VERDE ISLANDS FROM
20N29W TO 7N30W MOVING W AT 15 KT. THE WAVE REMAINS EMBEDDED
WITHIN A VERY MOIST ENVIRONMENT AS DEPICTED ON THE TOTAL
PRECIPITABLE WATER IMAGERY. CLUSTERS OF SCATTERED MODERATE
CONVECTION ARE FROM 8N-17N BETWEEN 25W-31W.

TROPICAL WAVE OVER THE E CARIBBEAN EXTENDS FROM 19N65W TO 10N69W
MOVING W-NW AT 20 KT. THE WAVE IS MOVING AROUND THE BROAD
SURFACE RIDGE THAT DOMINATES THE CENTRAL AND E ATLC AND REMAINS
EMBEDDED WITHIN AN AREA OF MODERATE MOISTURE AS DEPICTED ON THE
TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED SHOWERS ARE WITHIN
60 NM OF THE WAVE AXIS.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH PASSES THROUGH THE COASTAL AREAS OF GUINEA-
BISSAU AT 12N15W TO 8N20W. THE ITCZ CONTINUES W OF A TROPICAL
WAVE AT 9N34W AND CONTINUES TO 7N45W TO 8N54W TO THE COAST OF
GUYANA AT 8N59W. BESIDES THE CONVECTION MENTIONED IN THE
TROPICAL WAVE SECTION...SCATTERED MODERATE TO ISOLATED STRONG
CONVECTION IS FROM 5N-11N BETWEEN 17W-21W. ISOLATED MODERATE
CONVECTION IS FROM 6N-10N BETWEEN 34W-60W.

...DISCUSSION...

GULF OF MEXICO...

AS OF 2100 UTC...A COLD FRONT IS ALONG THE COAST OF TEXAS FROM
HOUSTON TO BROWNSVILLE DRIFTING E. ISOLATED MODERATE CONVECTION
IS WITHIN 90 NM OF THE FRONT. SURFACE RIDGING REMAINS OVER N
FLORIDA AND THE NE GULF OF MEXICO. A SMALL CYCLONIC SWIRL IS
NOTED ON VISIBLE SATELLITE IMAGERY JUST W OF THE DRY TORTUGAS
WITH NO PRECIPITATION. MOSTLY FAIR WEATHER IS OVER THE REMAINDER
OF THE GULF. IN THE UPPER LEVELS...AN UPPER LEVEL RIDGE IS OVER
THE GULF WITH UPPER LEVEL MOISTURE OVER THE NW GULF AND STRONG
SUBSIDENCE ELSEWHERE. EXPECT THE COLD FRONT TO BE OVER THE NW
GULF FOR THE NEXT 24 HOURS WITH CONVECTION.

CARIBBEAN SEA...

A DISSIPATING STATIONARY FRONT IS ALL ALONG THE S COAST OF CUBA.
ISOLATED MODERATE CONVECTION IS WITHIN 60 NM OF THE FRONT. A
TROPICAL WAVE IS OVER THE E CARIBBEAN WITH SHOWERS. SEE ABOVE.
A SURFACE TROUGH IS OVER THE CENTRAL CARIBBEAN SEA S OF JAMAICA
FROM 18N78W TO 10N79W. SLOW DEVELOPMENT OF THIS TROUGH IS
POSSIBLE DURING THE NEXT COUPLE OF DAYS WHILE IT MOVES SLOWLY
NORTHWESTWARD. THIS SYSTEM HAS A LOW CHANCE OF BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS. AFTER THAT TIME...
CONDITIONS ARE EXPECTED TO BE MORE CONDUCIVE FOR DEVELOPMENT
WHEN THE SYSTEM MOVES TOWARD THE NORTHWESTERN CARIBBEAN SEA AND
THE SOUTHEASTERN GULF OF MEXICO. THIS SYSTEM HAS A MEDIUM CHANCE
OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS. CLUSTERS
OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE FROM 10N-
18N BETWEEN 71W-78W. ELSEWHERE...AFTERNOON AND EVENING AIRMASS
THUNDERSTORMS ARE OVER HISPANIOLA ...AND JAMAICA. SCATTERED
MODERATE CONVECTION IS INLAND OVER CENTRAL AMERICA FROM COSTA
RICA TO THE YUCATAN PENINSULA WITH STRONGEST CONVECTION OVER
NICARAGUA. A MONSOON TROUGH EXTENDS FROM N COLOMBIA AT 8N75W TO
BEYOND COSTA RICA AT 10N85W. SCATTERED MODERATE TO ISOLATED
STRONG CONVECTION IS FROM 6N-10N BETWEEN 75W-84W. IN THE UPPER
LEVELS...AN UPPER LEVEL TROUGH IS OVER THE NW CARIBBEAN WITH
STRONG SUBSIDENCE. AN UPPER LEVEL RIDGE IS OVER THE CENTRAL
CARIBBEAN WITH SIGNIFICANT MOISTURE. A SMALL UPPER LEVEL LOW IS
OVER THE WINDWARD ISLANDS NEAR 13N61W WITH STRONG SUBSIDENCE.
EXPECT CONTINUED CONVECTION OVER THE CENTRAL AND SW CARIBBEAN
OVER THE NEXT 24 HOURS DUE TO THE SURFACE TROUGH.

HISPANIOLA...

BANDS OF THUNDERSTORMS ARE NOW OVER HISPANIOLA MOVING FROM S TO
N. UPPER LEVEL DIFFLUENCE IS ALSO OVER THE ISLAND.  EXPECT
SHOWERS AND THUNDERSTORMS TO PERSIST FOR THE NEXT 24 HOURS.

ATLANTIC OCEAN...

A QUASI-STATIONARY FRONT IS OVER THE W ATLANTIC FROM 31N63W TO
THE S BAHAMAS AT 22N71W. A DISSIPATING QUASI-STATIONARY FRONT
CONTINUES TO E CUBA AT 20N74W. ISOLATED MODERATE CONVECTION IS
FROM 20N-31N BETWEEN 64W-71W. A TROPICAL DEPRESSION ELEVEN IS
OVER THE CENTRAL ATLANTIC. SEE ABOVE. 1019 MB HIGH IS OVER THE
CENTRAL ATLANTIC NEAR 25N41W. ANOTHER 1019 MB HIGH IS OVER THE E
ATLANTIC NEAR 26N24W.  OF NOTE IN THE UPPER LEVELS...A SMALL
UPPER LEVEL LOW IS CENTERED OVER THE CENTRAL ATLANTIC NEAR
30N50W. UPPER LEVEL DIFFLUENCE IS SE OF THE CENTER CONTRIBUTING
TO THE TROPICAL DEPRESSION ELEVEN CONVECTION. EXPECT OVER THE
NEXT 24 HOURS FOR THE QUASI-STATIONARY FRONT TO DISSIPATE TO A
SURFACE TROUGH... AND FOR TROPICAL DEPRESSION ELEVEN TO MOVE
SLOWLY NE WITH CONVECTION.

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

$$
FORMOSA


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