[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 180554
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT TUE OCT 18 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...SPECIAL FEATURES...
A BROAD AREA OF LOW PRESSURE THAT COVERS THE FAR NW CARIBBEAN...
SE GULF OF MEXICO AND THE YUCATAN PENINSULA CONTINUES TO PRODUCE
A LARGE AREA OF SHOWERS/THUNDERSTORMS WELL REMOVED FROM THE LOW
LEVEL CENTER. THE POTENTIAL FOR THIS SYSTEM TO DEVELOP APPEARS
TO BE DECREASING AND NOW HAS A LOW CHANCE OF BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS AS IT BEGINS TO MOVE N-NE AT
9-13 KT. REGARDLESS OF DEVELOPMENT...THIS SYSTEM IS EXPECTED TO
CONTINUE TO PRODUCE LOCALLY HEAVY RAINFALL...GUSTY WINDS...AND
POSSIBLE SEVERE WEATHER OVER THE FLORIDA KEYS...THE FLORIDA
PENINSULA...SOUTHERN GEORGIA...AND COASTAL SECTIONS OF THE
CAROLINAS OVER THE NEXT DAY OR SO.

...TROPICAL WAVES...

TROPICAL WAVE IS ANALYZED FROM 14N27W TO 7N33W MOVING W AT NEAR
15 KT. WAVE IS EMBEDDED WITHIN BROAD AREA OF MOISTURE AS
DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. WAVE IS
BENEATH AN UPPER RIDGE ENHANCING SCATTERED MODERATE/STRONG
CONVECTION FROM 13N-16N BETWEEN 22W-30W INCLUDING THE SOUTHERN
MOST CAPE VERDE ISLANDS.

TROPICAL WAVE IS ANALYZED IN THE CENTRAL TROPICAL ATLC FROM
13N45W TO 6N49W MOVING W NEAR 15 KT. SCATTERED MODERATE/STRONG
CONVECTION IS FROM 6N-8N BETWEEN 46W-51W.

TROPICAL WAVE IS ANALYZED IN THE E CARIBBEAN FROM 20N65W TO
10N67W MOVING 10-15 KT. WAVE IS WELL DEFINED IN THE UPPER LEVEL
SATELLITE WINDS S OF 16N AND IN THE LOW LEVEL CLOUD PATTERN ON
SATELLITE IMAGERY ALSO S OF 16N. SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS ARE S OF 14N TO THE COAST OF VENEZUELA BETWEEN
63W-70W.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA TO THE COAST NEAR
18N16W. THE ITCZ IS DISRUPTED BY THE PRESENCE OF THE TROPICAL
WAVES. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION
ARE WITHIN 150 NM ALONG THE COAST OF W AFRICA FROM LIBERIA/
SIERRA LEONE BORDER TO SENEGAL/MAURITANIA BORDER. A PAIR OF 1008
MB LOW ARE ANALYZED BETWEEN THE TROPICAL WAVES NEAR 9N37W AND
9N43W.

...DISCUSSION...

GULF OF MEXICO...
A 1003 MB LOW IS CENTERED ALONG THE N COAST OF THE YUCATAN
PENINSULA NEAR 22N89W. SCATTERED/NUMEROUS STRONG CONVECTION IS
FROM THE COAST OF CUBA TO 25N BETWEEN 83W-86W WITH SCATTERED TO
HEAVY RAINS COVERING THE REMAINDER OF THE AREA S OF 27N E OF 87W
TO OVER FLORIDA AND THROUGH THE STRAITS OF FLORIDA. A BROAD
UPPER RIDGE COVERS THE GULF ANCHORED IN THE YUCATAN CHANNEL.
THERE IS A DISTINCT BOUNDARY BETWEEN THE MOIST TROPICAL AIR TO
THE SE AND STRONG SUBSIDENCE/DRY STABLE AIR TO THE NW THAT
EXTENDS FROM CEDAR KEY FLORIDA ALONG 24N90W TO TUXPAN MEXICO.
THE LOW CENTER IS EXPECTED TO TRACK SLOWLY NE TONIGHT AND LIKELY
WEAKEN REACHING NEAR 24N88W TUE MORNING THEN MOVE INLAND ACROSS
THE FLORIDA BIG BEND REGION TUE NIGHT. A TROUGH WILL TRAIL SW
FROM THE LOW IN ADVANCE OF A STRONG COLD FRONT THAT WILL ENTER
THE NW WATERS EARLY TUE THEN WILL MOVE QUICKLY SE ACROSS THE
GULF WED EVENING. HIGH PRESSURE WILL BUILD OVER THE GULF IN THE
WAKE OF THE FRONT THROUGH SAT.

CARIBBEAN SEA...
THE UPPER RIDGE ANCHORED OVER THE YUCATAN CHANNEL COVERS MOST OF
THE CARIBBEAN NW OF A LINE FROM GUADELOUPE IN THE LEEWARD
ISLANDS TO THE GUAJIRA PENINSULA OF COLOMBIA. A BROAD E/W UPPER
RIDGE COVERS THE SE CARIBBEAN EXTENDING ACROSS THE TROPICAL
ATLC. EASTERLY SURFACE FLOW COMBINED WITH THE EASTERLY FLOW
ALOFT OVER THE SW CARIBBEAN IS GENERATING SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS S OF 12N BETWEEN 73W-79W TO INLAND OVER
COLOMBIA WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED
THUNDERSTORMS S OF 14N W OF 79W TO INLAND OVER CENTRAL AMERICA.
THE TROPICAL WAVE WILL DAMPEN OUT OVER THE CENTRAL CARIBBEAN BY
MID WEEK. A COLD FRONT WILL PUSH INTO THE NW CARIBBEAN WED
EVENING REACHING FROM CENTRAL CUBA TO E HONDURAS BY LATE THU
WHERE IT WILL STALL.

ATLANTIC OCEAN...
AN UPPER RIDGE AXIS EXTENDS FROM THE YUCATAN CHANNEL ACROSS S
FLORIDA NEAR 25N80W ALONG 26N67W TO 30N50W PROVIDING A DIFFLUENT
ENVIRONMENT TO ENHANCE SCATTERED SHOWERS AND POSSIBLE ISOLATED
THUNDERSTORMS WITHIN 150 NM OF LINE FROM FLORIDA NEAR 27N80W
ALONG 29N70W TO 32N52W. AN UPPER TROUGH EXTENDS ACROSS THE
CENTRAL ATLC FROM AN UPPER LOW 30N30W THROUGH A SECOND WEAKER
UPPER LOW NEAR 20N52W NARROWING INTO THE W TROPICAL ATLC TO NEAR
16N57W. THE NORTHERN UPPER LOW IS SUPPORTING A WEAK 1016 MB LOW
CENTERED NEAR 32N35W WITH A SURFACE TROUGH EXTENDING S ALONG
30N33W TO 27N34W WITH SCATTERED SHOWERS/THUNDERSTORMS FROM
30N-33N BETWEEN 26W-33W. A WEAK SURFACE RIDGE COVERS MOST OF THE
ATLC N OF 20N E OF 75W WITH A WEAKNESS IN THE VICINITY OF THE
ABOVE LOW/TROUGH. A BROAD UPPER RIDGE EXTENDS E/W ACROSS THE
TROPICAL ATLC. THE SURFACE RIDGE OVER THE W ATLC WILL SHIFT E
ALONG 30N THROUGH TUE. THE LOW IN THE GULF OF MEXICO WILL SHIFT
N-NE TUE AND WED AHEAD OF A STRONG COLD FRONT THAT WILL MOVE OFF
THE NE FLORIDA COAST WED EVENING THEN WILL REACH FROM 31N74W TO
CENTRAL CUBA BY EARLY THU WHERE IT WILL WEAKEN AND BECOME
STATIONARY FROM NEAR 31N70W TO CENTRAL CUBA FRI.

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

$$
PAW





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