[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 010548
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SUN OCT 01 2006

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN
SECTIONS OF SOUTH AMERICA...AND THE 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...
HURRICANE ISAAC IS CENTERED NEAR 32.5N 59.9W AT 01/0300 UTC
MOVING NORTH-NORTHWEST AT 9 KT. ESTIMATED MINIMUM CENTRAL
PRESSURE IS 989 MB. MAXIMUM SUSTAINED WIND SPEED IS 70 KT WITH
GUSTS TO 85 KT. SEE THE LATEST NHC FORECAST/ADVISORY UNDER
AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. A BAND
OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WEST OF THE
CENTER FROM 31N-37N BETWEEN 62W-64W. THE HURRICANE WILL BEGIN TO
INTERACT WITH A LARGE MID-LATITUDE TROUGH MOVING OFF THE EAST
COAST OF THE UNITED STATES AND WILL BECOME EXTRATROPICAL IN
ABOUT 36 HOURS.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 37W/38W S OF 21N MOVING W 15 KT. THE WAVE
HAS A WEAK INVERTED-V SIGNATURE AND IS EMBEDDED WITHIN DRY
AIR...THUS ONLY ISOLATED SHOWERS ARE NOTED.

TROPICAL WAVE IS ALONG 63W S OF 18N MOVING W 15 KT. WAVE IS
MOVING ACROSS THE EASTERN CARIBBEAN ENHANCING THE DEVELOPMENT OF
MODERATE TO STRONG CONVECTION OVER VENEZUELA. THE WAVE WILL PASS
MAINLY SOUTH OF THE VIRGIN ISLANDS AND PUERTO RICO TODAY.

TROPICAL WAVE IS ALONG 73W MOVING W AT 10-15 KT. WEAK WAVE
INVERTED-V SIGNATURE WITH SHOWERS AND THUNDERSTORMS FIRING UP
OVER HISPANIOLA AND COLOMBIA IN RESPONSE TO THE PASSING OF THE
WAVE AXIS. THIS WAVE IS ALSO GENERATING A CLUSTER OF SCATTERED
MODERATE/ISOLATED STRONG CONVECTION NEAR LAKE MARACAIBO
VENEZUELA.

TROPICAL WAVE IS ALONG 95W/96W OVER S MEXICO AND THE E PACIFIC
REGION WITH SCATTERED SHOWERS EXTENDING OVER THE BAY OF CAMPECHE
S OF 20N WEST OF 94W.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 11N14W 6N25W 7N36W 11N45W 9N60W.
SCATTERED MODERATE CONVECTION ARE FROM 2N-10N EAST OF 34W.
ISOLATED SHOWERS ARE ELSEWHERE.

...DISCUSSION...
GULF OF MEXICO...
DEEP LAYERED TROUGH COVERS THE E HALF OF THE US INTO THE GULF N
OF 26N WITH THE LEADING EDGE OF THE UPPER TROUGH AND ASSOCIATED
FRONTAL BOUNDARY IN THE W ATLC. A SHORTWAVE TROUGH AND SECOND
FRONTAL SYSTEM ARE MOVING THROUGH THE UPPER MISSISSIPPI
VALLEY. BROAD UPPER RIDGE ANCHORED OVER CENTRAL AMERICA AND IN
THE E PACIFIC REGION COVERS THE REMAINDER OF THE S GULF. DRY AIR
RESULTING IN MODERATE TO STRONG SUBSIDENCE DOMINATES THE
MAJORITY OF THE GULF AND THE STATE OF FLORIDA WHILE ABUNDANT
UPPER LEVEL MOISTURE IS SEEN OVER MEXICO AHEAD OF A SHORT WAVE
TROUGH. AS OF 0300 UTC A 1020 MB HIGH IS OVER THE
FLORIDA/GEORGIA BORDER WITH A RIDGE COVERING THE GULF. THIS IS
GIVING THE ENTIRE AREA FAIR CONDITIONS TONIGHT. HIGH PRESSURE
WILL BUILD OVER THE SOUTHEAST U.S. MONDAY AND TUESDAY WITH
INCREASING EASTERLY WINDS ACROSS THE GULF.

CARIBBEAN SEA...
BROAD UPPER RIDGE ANCHORED OVER CENTRAL AMERICA AND IN THE E
PACIFIC REGION COVERS THE W CARIBBEAN W OF 73W WITH AN EXTENSION
OF THE RIDGE EXTENDING ACROSS E CUBA AND THE BAHAMAS INTO THE W
ATLC. A SURFACE TROUGH IS PRODUCING HEAVY SHOWERS/SCATTERED
THUNDERSTORMS OVER EASTERN CUBA AND CENTRAL BAHAMAS. A 1009 MB
LOW IS IN THE SW CARIBBEAN NEAR 10N80W. AN UPPER LOW IN THE
CARIBBEAN IS S OF THE MONA PASSAGE NEAR 16N68W COVERING THE
REMAINDER OF THE CARIBBEAN. AN UPPER TROUGH EXTENDS FROM THE LOW
TO THE ABC ISLANDS INTO VENEZUELA. SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS ARE OVER THE E CARIBBEAN E OF 67W ASSOCIATED WITH
THE TROPICAL WAVE AND THE UPPER LOW/TROUGH OVER THE AREA.
MODERATE TRADE WINDS ARE BLOWING OVER THE BASIN.

ATLANTIC OCEAN...
DEEP LAYERED TROUGH OVER THE E US EXTENDS INTO THE W ATLC W OF
73W. THE ASSOCIATED FRONTAL SYSTEM ENTERS THE AREA NEAR 32N68W
THEN CONTINUES SW TO THE NORTHERN BAHAMAS. A SURFACE PRE-FRONTAL
TROUGH EXTENDS FROM 26N74W ACROSS THE BAHAMAS TO OVER EASTERN
CUBA...GENERATING SCATTERED MODERATE/ISOLATED STRONG CONVECTION
FROM 20N-25N BETWEEN 72W-78W. SIMILAR CONVECTION IS FOUND BEHIND
THE FRONTAL BOUNDARY NORTH OF 27N. ANOTHER SURFACE TROUGH RUNS
FROM 27N63W TO 20N69W. A DIFFLUENT PATTERN ALOFT IS ENHANCING
THE SHOWER/TSTM ACTIVITY ASSOCIATED WITH THIS TROUGH. A CUT-OFF
UPPER LOW IS IN THE CENTRAL ATLC NEAR 20N46W DRIFTING WESTWARD.
BROAD UPPER RIDGE COVERS THE E ATLC E OF 30W WITH A 1019 MB HIGH
CENTERED W OF THE CANARY ISLANDS NEAR 29N20W. A COLD FRONT IS
APPROACHING THE E-CENTRAL ATLC FROM THE NORTH. WIDELY SCATTERED
MODERATE CONVECTION IS AHEAD OF THE FRONT FROM 27N-31N BETWEEN
20W-34W.

$$
GR







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