[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 240008
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI SEP 23 2011

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 FEATURES...

TROPICAL STORM OPHELIA IS CENTERED NEAR 15.5N 53.8W AT 23/2100
UTC OR ABOUT 540 MI...870 KM E OF THE LEEWARD ISLANDS MOVING WNW
AT 13 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1001 MB. MAXIMUM
SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. SEE LATEST
NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21
KNHC FOR MORE DETAILS. TROPICAL-STORM-FORCE WINDS EXTEND OUTWARD
UP TO 260 MILES...415 KM...MAINLY NORTH AND EAST OF THE CENTER.
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 13N-20N
BETWEEN 48W-54W.

A 1009 MB LOW IS S OF THE CAPE VERDE ISLANDS NEAR 10N22W.
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 10N-12N
BETWEEN 21W-25W. ENVIRONMENTAL CONDITIONS ARE CURRENTLY
CONDUCIVE FOR ADDITIONAL DEVELOPMENT...AND THE LOW HAS A MEDIUM
CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

...TROPICAL WAVES...

TROPICAL WAVE IS ANALYZED FROM 19N34W TO 13N37 TO 6N37W MOVING
W AT 10 KT. VISIBLE SATELLITE IMAGERY AND LOW-LEVEL STREAMLINE
ANALYSIS INDICATES BROAD CYCLONIC FLOW IN THE VICINITY OF THE
WAVE AXIS. TOTAL PRECIPITABLE WATER IMAGERY INDICATES THAT
ENHANCED DEEP LAYER MOISTURE ACCOMPANIES THE WAVE. NO
SIGNIFICANT DEEP CONVECTION IS NOTED WITH THE WAVE.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 13N17W
TO THE LOW PRESSURE NOTED ABOVE NEAR 10N22W TO 8N32W. IN
ADDITION TO THE CONVECTION MENTIONED WITH THE LOW...WIDELY
SCATTERED MODERATE CONVECTION IS FROM 5N-8N BETWEEN 22W-32W.

...DISCUSSION...

GULF OF MEXICO...
THE TAIL END OF A COLD FRONT IS OVER THE GULF OF MEXICO FROM THE
FLORIDA PANHANDLE AT 30N87W TO THE NW GULF AT 25N95W. SCATTERED
SHOWERS ARE FROM 28N-31N BETWEEN 86W-89W. A SURFACE TROUGH
EXTENDS FROM THE E GULF AT 27N84W TO THE YUCATAN PENINSULA AT
19N89W. SCATTERED MODERATE CONVECTION IS FROM 23N-27N BETWEEN
84W-86W...WHILE SCATTERED MODERATE TO STRONG CONVECTION IS
INLAND OVER THE YUCATAN PENINSULA N OF 17N. AIRMASS RAIN AND
THUNDERSTORMS ARE INLAND OVER FLORIDA E OF 81W FROM JACKSONVILLE
TO MIAMI. IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS
SUPPORTING THE SURFACE FRONT AND TROUGH HOWEVER STRONG
SUBSIDENCE IS SUPPRESSING OVERALL CONVECTION. MOST OF THE W GULF
HAS FAIR WEATHER. EXPECT...THE FRONT TO DRIFT OVER N FLORIDA IN
24 HOURS WITH CONTINUED CONVECTION OVER THE E GULF AND
FLORIDA.

CARIBBEAN SEA...
A SURFACE TROUGH IS OVER THE YUCATAN PENINSULA. SEE ABOVE. A
MONSOON TROUGH EXTENDS FROM N COLOMBIA TO COSTA RICA. SCATTERED
MODERATE TO STRONG CONVECTION IS OVER PANAMA AND THE SW
CARIBBEAN FROM 7N-11N BETWEEN 78W-83W. 10-20 KT TRADEWINDS ARE
OVER THE CARIBBEAN SEA WITH STRONGEST WINDS ALONG THE COAST OF N
COLOMBIA. SCATTERED MODERATE CONVECTION IS OVER THE HIGHER
ELEVATIONS OF HISPANIOLA...JAMAICA...AND CUBA. WIDELY SCATTERED
MODERATE CONVECTION IS ALSO OVER THE CENTRAL CARIBBEAN S OF
JAMAICA FROM 13N-17N BETWEEN 72W-83W. EXPECT THE WESTERN EXTENT
OF THE CONVECTIVE BANDING FROM OPHELIA TO BE OVER THE E
CARIBBEAN WITHIN 24 HOURS. ALSO EXPECT CONTINUED CONVECTION OVER
THE W CARIBBEAN AND CENTRAL AMERICA W OF 80W OVER THE NEXT 24
HOURS.

ATLANTIC OCEAN...
A SURFACE TROUGH IS OVER THE BAHAMAS ALONG 28N78W 23N79W.
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 23N-28N
BETWEEN 72W-78W. A 1027 MB HIGH IS OVER THE W ATLANTIC NEAR
35N60W.  ANOTHER 1021 MB HIGH IS OVER THE E ATLANTIC NEAR
32N26W. SURFACE RIDGING WITH MOSTLY FAIR WEATHER IS OVER THE
ATLANTIC FROM 20N-32N BETWEEN 20W-70W. EXPECT CONTINUED
CONVECTION OVER THE BAHAMAS OVER THE NEXT 24 HOURS.

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

$$
FORMOSA





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