[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 180554
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT MON OCT 18 2010

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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND
RADAR.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0445 UTC.

...ITCZ...

ITCZ AXIS IS ANALYZED ALONG 9N23W 11N35W THEN RESUMES NEAR 7N40W
6N48W 5N55W. A SURFACE TROUGH IS N OF THE ITCZ BETWEEN W AFRICA
AND THE CAPE VERDE ISLANDS ALONG 19N19W TO 10N22W WITH CLUSTERS
OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION WITHIN 90/120
NM OF A LINE FROM 9N22W TO 24N18W. A SECOND SURFACE TROUGH IS
EMBEDDED WITHIN THE ITCZ FROM 14N35W THROUGH A 1010 MB LOW NEAR
11N36W TO 7N37W WITH SCATTERED MODERATE/STRONG CONVECTION FROM
11N-14N BETWEEN 34W-37W. SCATTERED MODERATE/STRONG CONVECTION IS
S OF THE ITCZ WITHIN 120 NM OF A LINE FROM 4N37W TO 8N32W WITH
CLUSTERS OF SIMILAR CONVECTION FROM 4N-9N BETWEEN 35W-43W.
CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE
FROM 3N-9N BETWEEN 17W-23W.

...DISCUSSION...

GULF OF MEXICO...
BROAD UPPER RIDGE ANCHORED IN THE CARIBBEAN COVERS THE GULF WITH
SOUTHWESTERLY FLOW AND DRY AIR ALOFT...AND THUS MOSTLY CLEAR
SKIES ACROSS THE GULF TONIGHT. A SHORTWAVE UPPER TROUGH IS
MOVING ACROSS E TEXAS BUT IS NOT PRODUCING ANY SIGNIFICANT
WEATHER AT THE MOMENT. A SURFACE ALSO COVERS THE GULF INTO THE W
ATLC ANCHORED BY A 1020 MB HIGH OVER N ALABAMA.

CARIBBEAN SEA...
THE PRIMARY FEATURE FOR THE CARIBBEAN IS A SURFACE TROUGH THAT
EXTENDS FROM 16N76W THROUGH A 1010 MB LOW CENTERED NEAR 12N78W
TO INLAND OVER S NICARAGUA TO NEAR 11N85W...CONDITIONS ARE
BECOMING MORE FAVORABLE FOR POSSIBLE DEVELOPMENT OVER THE NEXT
DAY OR TWO BEFORE BEFORE IT INTERACTS WITH LAND. SCATTERED/
NUMEROUS STRONG CONVECTION IS N OF THE TROUGH AXIS WITHIN 30/45
NM OF LINE FROM 15N80W TO 14N82W WITH SCATTERED MODERATE/STRONG
CONVECTION COVERING THE REMAINDER OF THE AREA WITHIN 180 NM NW
OF THE TROUGH BETWEEN 79W-83W. BROAD UPPER RIDGE COVERS THE
CARIBBEAN ANCHORED NEAR 16N76W ENHANCING THE ACTIVITY ABOVE AND
CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE
REMAINDER OF THE W CARIBBEAN SW OF A LINE FROM COLOMBIA NEAR
12N72W TO 20N82W INCLUDING THE PORTIONS OF CENTRAL AMERICA AND A
SMALL CLUSTER OVER S HAITI AND THE GULF OF GONAVE. ALTHOUGH AN
ELONGATED N/S UPPER LOW IS OVER THE LESSER ANTILLES THE AREA IS
DOMINATED BY DRY AIR ALOFT AND IS NOT PRODUCING ANY SIGNIFICANT
WEATHER AT THIS TIME LEAVING THE CARIBBEAN E OF 70W UNDER RATHER
CLEAR SKIES TONIGHT.

ATLANTIC OCEAN...
BROAD UPPER TROUGH COVERS THE W INTO THE CENTRAL ATLC W OF 45W
SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 32N47W SW
ALONG 25N56W 23N66W ACROSS THE BAHAMAS NEAR 22N73W TO A WEAK
1013 MB LOW ALONG THE N COAST OF CUBA NEAR 21N77W. A PREFRONTAL
SURFACE TROUGH EXTENDS FROM 26N53W ALONG 22N61W TO 21N69W.
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 75 NM BOTH
SIDES OF THE FRONT W OF THE BAHAMA ISLANDS TO INLAND OVER CUBA
WITH SCATTERED SHOWERS BETWEEN THE SURFACE TROUGH AND THE
FRONTAL BOUNDARY. A SURFACE RIDGE COVERS THE W ATLC ANCHORED
OVER THE ALABAMA WITH COLD AIR STRATOCUMULUS CLOUDS DOTTING THE
AREA BEHIND THE FRONT. AN UPPER RIDGE JUST TO THE E OF THE UPPER
TROUGH OVER THE W/CENTRAL ATLC IS GENERATING SCATTERED SHOWERS
WITHIN 45/60 NM OF LINE FROM 25N50W TO BEYOND 32N41W. A SECOND
UPPER TROUGH IS OVER THE E ATLC EXTENDING THROUGH 32N28W TO NEAR
20N30W BECOMING A SHEAR AXIS SW ALONG 15N37W TO 8N43W AND
SUPPORTING A SURFACE TROUGH THAT EXTENDS THROUGH 32N24W ALONG
27N31W 21N39W 20N45W TO 21N49W GENERATING SCATTERED SHOWERS
WITHIN 75 NM E OF THE TROUGH N OF 27N LEAVING THE REMAINDER OF
THE THE E ATLC UNDER FAIR SKIES TONIGHT.


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

$$
PAW





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