[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 311029
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI AUG 31 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN
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...METEOROLOGICAL ANALYSIS...
WEATHER OBSERVATIONS...AND RADAR.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0945 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 29W/30W S OF 21N DRIFTING W WITH A 1011
MB LOW ALONG THE WAVE NEAR 14.5N. BROAD ELONGATED LOW/MID LEVEL
CYCLONIC ROTATION COVERING THE AREA FROM 12N-19N BETWEEN 28W-37W
WITH SEVERAL POSSIBLE ILL-DEFINED LOW LEVEL CIRCULATIONS.
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 13N-17N
BETWEEN 30W-35W.

TROPICAL WAVE IS ALONG 55W/56W S OF 16W MOVING W 15 KT WITH A
1010 MB LOW ALONG THE WAVE NEAR 11N. BROAD BUT LOW AMPLITUDE
LOW/MID LEVEL CYCLONIC ROTATION COVERS THE AREA FROM 9N-14N
BETWEEN 53W-59W. THIS WAVE/LOW CONTINUES TO BECOME BETTER
ORGANIZED AND COULD BECOME A TROPICAL DEPRESSION LATER TODAY.
SCATTERED MODERATE/STRONG CONVECTION IS FROM 9N-13N BETWEEN
52W-59W.

TROPICAL WAVE IS ALONG 78W S OF 23N MOVING W NEAR 10 KT. NARROW
INVERTED-V CURVATURE REMAINS WEAK IN THE CARIBBEAN AND IS
PRODUCING LIMITED SHOWER ACTIVITY DUE TO THE RATHER DRY STABLE
AIR.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 12N15W 14N28W 8N42W 12N52W 11N64W.
IN ADDITION TO SHOWERS/CONVECTION ASSOCIATED WITH THE TROPICAL
WAVES...CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 200
NM ALONG THE COAST OF SW AFRICA S OF 10N ACROSS THE PRIME
MERIDIAN AND WITHIN 90/120 NM OF THE ITCZ AXIS FROM 38W-53W.

DISCUSSION...
GULF OF MEXICO...
UPPER TROUGH EXTENDS FROM SE LOUISIANA TO THE COAST OF MEXICO
NEAR TAMPICO. BROAD UPPER RIDGE EXTENDS FROM S MEXICO ACROSS THE
BAY OF CAMPECHE AND THE REMAINDER OF THE GULF TO OVER GEORGIA TO
ALONG THE COAST OF THE CAROLINAS. AT THE SURFACE...THE WEAK 1011
MB LOW PREVIOUSLY ALONG THE COAST OF MEXICO IS NOW A SURFACE
TROUGH EXTENDING FROM VERACRUZ MEXICO TO NEAR 23N93W...A FRONTAL
BOUNDARY REMAINS INLAND OVER THE SE US FROM E TENNESSEE TO
CENTRAL TEXAS...AND A WEAK SURFACE RIDGE EXTENDS FROM THE
CENTRAL PLAIN STATES OVER THE W GULF AND NE MEXICO WITH A 1017
MB HIGH CENTERED OVER THE RIO GRANDE NEAR 27N99W. SCATTERED
MODERATE/STRONG CONVECTION IS INLAND AND WITHIN 90 NM ALONG THE
COAST OF MEXICO S OF 22N W OF 92W. SCATTERED
SHOWERS/THUNDERSTORMS COVER THE REMAINDER OF THE AREA S OF 26N W
OF 87W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ALONG THE N
AND E GULF COASTS FROM GALVESTON TEXAS TO THE FLORIDA STRAITS.

CARIBBEAN SEA...
AN UPPER RIDGE OVER THE GULF OF MEXICO COVERS THE W CARIBBEAN W
OF 87W. AN UPPER TROUGH EXTENDS FROM OVER HAITI SW TO AN UPPER
LOW IN THE SW CARIBBEAN NEAR 13N80W CONTINUING TO OVER PANAMA
AND COSTA RICA. AN UPPER RIDGE COVERS THE E CARIBBEAN EXTENDING
FROM AN UPPER HIGH OVER VENEZUELA TO THE MONA PASSAGE. ALTHOUGH
ITCZ AXIS EXTENDS ACROSS THE N PORTION OF SOUTH AMERICA AND THE
SW CARIBBEAN FROM COLOMBIA TO PANAMA/COSTA RICA INTO THE E
PACIFIC REGION IT IS ONLY AMBLE TO GENERATE SOME ISOLATED
SHOWERS/THUNDERSTORMS S OF 13N W OF 70W DUE TO THE ABUNDANCE OF
DRY AIR. SCATTERED CLUSTERS OF SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS DOT THE N CARIBBEAN N OF 16N FROM 70W-82W.
SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 75 NM OF LINE FROM
THE WINDWARD ISLANDS NEAR 12N61W NW TO OVER PUERTO RICO NEAR
18N66W. MODERATE/STRONG EASTERLY TRADE WINDS REMAIN ACROSS THE
CARIBBEAN.

ATLANTIC OCEAN...
BROAD UPPER RIDGE COVERS THE W ATLC W OF 77W WITH A NARROW UPPER
TROUGH EXTENDING THROUGH 32N72W S ACROSS THE CENTRAL BAHAMA
ISLANDS TO THE N COAST OF CUBA NEAR 21N75W. A WEAK 1010 MB LOW
IS IN THE W ATLC NEAR 30N74W WITH A SURFACE TROUGH EXTENDING S
TO OVER THE N BAHAMA ISLANDS NEAR 24N78W GENERATING SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 25N TO OVER THE GREATER
ANTILLES BETWEEN 72W-79W. AN UPPER HIGH IS JUST TO THE E NEAR
27N68W GIVING THE AREA ENOUGH DIFFLUENCE TO GENERATE CLUSTERS OF
SCATTERED MODERATE/ISOLATED STRONG CONVECTION N OF 25N BETWEEN
60W-74W. BROAD UPPER TROUGH EXTENDING FROM 27N44W TO 17N53W AND
AN UPPER HIGH CENTERED NEAR 23N29W ARE BOTH RATHER BENIGN
FEATURES AND COUPLED WITH THE DRY STABLE AIR THAT COVERS THE
ATLC E OF 60W WITH A WEAK SURFACE RIDGE ALSO COVERING THE ATLC E
OF 65W GIVES THE REMAINDER OF THE ATLC FAIR WEATHER CLOUDS WITH
LIGHT TO MODERATE TRADE WINDS.

$$
WALLACE



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