[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211032
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT MON AUG 21 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 35W/36W S OF 17N MOVING W 10-15 KT. BROAD
MID LEVEL ROTATION IS OBSERVED ON INFRARED SATELLITE IMAGERY
ALONG THE ITCZ. CONVECTION IS CONFINED TO WITHIN THE ITCZ AREA.

TROPICAL WAVE IS ALONG 52W/53W S OF 19N MOVING W NEAR 15-20 KT.
WELL DEFINED INVERTED-V CURVATURE IS OBSERVED ON INFRARED
SATELLITE IMAGERY. SCATTERED MODERATE/STRONG CONVECTION IS FROM
8N-14N BETWEEN 34W-39W.

TROPICAL WAVE IN THE E CARIBBEAN IS ALONG 70W S OF 18N MOVING W
10-15 KT. WAVE IS BENEATH THE E EDGE OF AN UPPER RIDGE WITH ONLY
ISOLATED SHOWERS FROM 15N-18N BETWEEN 67W-72W.

TROPICAL WAVE IN THE W CARIBBEAN IS ALONG 85W S OF 18N MOVING W
10-15 KT. WAVE IS MOSTLY INLAND OVER CENTRAL AMERICA AND ALONG
AND BENEATH AN UPPER RIDGE MASKING THE CLASSIC SATELLITE
SIGNATURE. NO ASSOCIATED SHOWERS/CONVECTION.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 14N16W 7N25W 9N34W 8N40W 12N55W
10N62W ACROSS THE N PORTION OF SOUTH AMERICA AND PANAMA INTO THE
E PACIFIC REGION. A TROPICAL WAVE IS ALONG THE COAST OF AFRICA
WITH A BROAD MID LEVEL ROTATION OBSERVED ON INFRARED SATELLITE
IMAGERY BUT WAS NOT ANALYZED AS SUCH DUE TO THE LACK OF
SUPPORTING SURFACE AND UPPER AIR DATA. SCATTERED MODERATE TO
STRONG CONVECTION COVERING THE AREA FROM 9N-15N BETWEEN 18W-22W.
CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE WITHIN
120/150 NM OF THE ITCZ AXIS FROM 16W-24W. CLUSTERS OF SCATTERED
MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 120/150 NM OF THE
AXIS FROM 41W-62W.

...DISCUSSION...
GULF OF MEXICO...
BROAD UPPER RIDGE ANCHORED OVER NE TEXAS EXTENDS OVER THE N GULF
N OF 27N. AN UPPER TROUGH EXTENDS ACROSS THE S GULF FROM THE SW
COAST OF FLORIDA NEAR NAPLES TO AN UPPER LOW ALONG THE COAST OF
MEXICO JUST BETWEEN TAMPICO AND VERACRUZ PROVIDING ENOUGH
DIFFLUENCE OVER THE S GULF TO GENERATE CLUSTERS OF SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS OVER THE AREA S OF A LINE FROM
NEAR TAMPA FLORIDA TO THE COAST OF MEXICO JUST N OF TAMPICO.

CARIBBEAN SEA...
BROAD UPPER RIDGE EXTENDS ACROSS THE CARIBBEAN FROM NICARAGUA/
HONDURAS BORDER ALONG 16N77W ACROSS HISPANIOLA INTO THE W ATLC.
THIS IS PROVIDING ENOUGH DIFFLUENCE OVER W CARIBBEAN TO GENERATE
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF A LINE FROM THE
PANAMA/COSTA RICA BORDER NW TO THE WINDWARD PASSAGE WITH THE
SCATTERED MODERATE/STRONG CONVECTION FROM 14N-18N BETWEEN
78W-82W. SCATTERED STRONG CONVECTION IS S OF 10N W OF 79W TO
INLAND OVER COLOMBIA AND E PANAMA ASSOCIATED WITH THE ITCZ AXIS
THAT EXTENDS ALONG 8N ACROSS THAT AREA. MODERATE/STRONG
TRADEWINDS ARE ACROSS THE AREA.

ATLANTIC OCEAN...
SMALL UPPER LOW IS IN THE W ATLC CENTERED NEAR 29N80W AND IS
GENERATING THE SCATTERED SHOWERS/THUNDERSTORMS FROM 23N-29N
BETWEEN 75W-80W. AN UPPER LOW REMAINS SE OF BERMUDA NEAR 31N62W
WITH AN ASSOCIATED SURFACE TROUGH EXTENDING FROM 22N67W-29N64W.
HOWEVER...WITH DRY AIR IN PLACE THIS FEATURE IS ONLY ABLE TO
GENERATE SCATTERED SHOWERS FROM 22N-28N BETWEEN 60W-68W. THE
UPPER RIDGE EXTENDS FROM THE CARIBBEAN ACROSS HISPANIOLA TO NEAR
24N66W IN THE W ATLC. THE REMAINDER OF THE ATLC IS DOMINATED BY
MOSTLY BENIGN FEATURES WHICH INCLUDE AN UPPER LOW NEAR 23N42W
AND AN UPPER HIGH NEAR 27N24W BUT WITH DRY AIR IN PLACE OVER THE
E ATLC NO SIGNIFICANT CLOUDS OR SHOWERS ARE ASSOCIATED WITH
THESE FEATURES. A SURFACE RIDGE DOMINATES THE MUCH ATLC WITH THE
SURFACE HIGHS N OF THE REGION. SIGNIFICANT AMOUNTS OF AFRICA
DUST COVER THE E TROPICAL ATLC FROM THE ITCZ TO 24N BETWEEN THE
CAPE VERDE ISLANDS TO 55W WITH CLEARING E OF THE ISLANDS.

$$
WALLACE



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