[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 031836 AAA
TWDAT

TROPICAL WEATHER DISCUSSION...AMENDED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT WED AUG 03 2005

UPDATED FOR T.S. HARVEY...

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...
CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...
NORTHEASTERN 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 1200 UTC SURFACE ANALYSIS AND
SATELLITE IMAGERY THROUGH 1745 UTC.

...SPECIAL FEATURE...
TROPICAL STORM HARVEY WAS NEAR 30.9N 67.7W AT 03/1800 UTC
MOVING NORTHEAST 9 KT...OR ABOUT 200 MILES/320 KM WEST-SOUTHWEST
OF BERMUDA. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 999 MB.
THE MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT.
SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT3/WTNT23 KNHC OR MIATCPAT3/WTNT33 KNHC FOR MORE DETAILS.
SCATTERED MODERATE TO STRONG SHOWERS AND THUNDERSTORMS FROM 24N
TO 30N BETWEEN 61W AND 66W. SCATTERED MODERATE TO ISOLATED
STRONG SHOWERS AND THUNDERSTORMS FROM 30N TO 35N BETWEEN 60W AND
67W. SCATTERED MODERATE SHOWERS AND THUNDERSTORMS FROM 27N TO
31N BETWEEN 68W AND 71W TO THE SOUTH OF HARVEY...CLOSER TO THE
MIDDLE TO UPPER LEVEL CYCLONIC CENTER WHICH IS SOUTH OF HARVEY.
SCATTERED MODERATE TO ISOLATED STRONG SHOWERS AND THUNDERSTORMS
ARE WEST OF HARVEY...FROM 28N TO 31N BETWEEN 74W AND 79W...IN
AN AREA OF BROAD LOW PRESSURE AND A DISSIPATING STATIONARY
FRONT/SURFACE TROUGH...WHICH PASSES THROUGH 32N73W 30N80W TO
FLORIDA 30N85W.

...TROPICAL WAVES...

EASTERN ATLANTIC TROPICAL WAVE NOW ALONG 29W/30W SOUTH OF 17N
MOVING WEST 10 KT. A 1008 MB LOW PRESSURE CENTER IS ALONG THE
WAVE NEAR 11N. THIS LOW CENTER IS FORECAST BY THE GFS MODEL TO
CONTINUE ITS WESTWARD MOVEMENT FOR AT LEAST THE NEXT 96 HOURS
ALONG MORE OR LESS THE SAME LATITUDE. NUMEROUS STRONG SHOWERS
AND THUNDERSTORMS FROM 11N TO 13N BETWEEN 27W AND 28.5W...AND
IN CLUSTERS FROM 8N TO 13N BETWEEN 30W AND 32W.

CARIBBEAN SEA TROPICAL WAVE IS ALONG 70W/71W SOUTH OF 20N MOVING
WEST 10 KT. THE EXISTENCE OF THIS WAVE IS NOT APPARENT IN THE
LOW CLOUD MOVEMENTS ON CURRENT VISIBLE IMAGERY. ISOLATED
MODERATE SHOWERS AND THUNDERSTORMS HAVE BEEN DEVELOPING WITHIN
15 TO 20 NM ON EITHER SIDE OF 15N81W 17N78W...AND FROM THE
JAMAICA CHANNEL TO THE SOUTHERN COAST OF HISPANIOLA TO THE
SOUTHEASTERN DOMINICAN REPUBLIC. THIS PRECIPITATION MAY BE
MORE RELATED TO THE TRADEWIND FLOW RATHER THAN WITH THE WAVE.
DUST IS SEEN ON IN THE ATMOSPHERE ON VISIBLE IMAGERY WEST OF
THIS LINE OF PRECIPITATION.

WESTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 80W SOUTH OF 19N
MOVING WEST 10 KT. 79W/80W S OF 19N MOVING W 10 KT. LOW CLOUDS
CORRELATE WELL WITH THE POSITION OF THIS WAVE. SHOWERS AND
THUNDERSTORMS...NEAR THE ITCZ AND AT THE BASE OF A MIDDLE TO
UPPER LEVEL TROUGH...ARE IN THE SOUTHWESTERN CORNER OF THE
CARIBBEAN SEA.

...THE ITCZ...

ITCZ 14N16W 11N26W...10N33W 9N50W 9N61W. WIDELY SCATTERED TO
SCATTERED MODERATE/ISOLATED STRONG SHOWERS AND THUNDERSTORMS
FROM 9N TO 12N BETWEEN AFRICA AND 27W. ISOLATED MODERATE SHOWERS
AND POSSIBLE THUNDERSTORMS FROM 7N TO 12N BETWEEN 34W AND 46W...
FROM THE COAST OF FRENCH GUIANA TO 12N BETWEEN 50W AND 53W.
THE CLOUDS WITH THIS PRECIPITATION ARE BEING SHEARED BY THE
UPPER LEVEL SOUTHEASTERLY WIND FLOW ACROSS THE CLOUD TOPS.

...DISCUSSION...

THE GULF OF MEXICO...
BROAD MIDDLE TO UPPER LEVEL CYCLONIC FLOW WEST OF 90W...COMING
FROM A MEXICO 28N104W CYCLONIC CIRCULATION CENTER. UPPER LEVEL
MOISTURE FROM THE PACIFIC OCEAN IS MOVING ACROSS INTERIOR MEXICO
INTO THE GULF OF MEXICO WEST OF 90W. ISOLATED MODERATE SHOWERS
AND THUNDERSTORMS ARE INCREASING IN NUMBER IN THE GULF WATERS
NORTH OF 24N...ESPECIALLY IN BETWEEN THE UPPER LEVEL
ANTICYCLONIC FLOW COVERING THE GULF EAST OF 86W AND THE 90W
CYCLONIC FLOW. ISOLATED MODERATE SHOWERS SOUTH OF 23N BETWEEN
94W AND 98W...POSSIBLY ENHANCED BY THE 95W/96W TROPICAL WAVE.
THE SURFACE PRESSURE GRADIENT IN THE GULF OF MEXICO IS WEAK.

THE CARIBBEAN SEA...
A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM EAST-CENTRAL CUBA
TOWARD THE SOUTHWESTERN CORNER OF THE AREA NEAR 10N80W. NUMEROUS
STRONG SHOWERS AND THUNDERSTORMS HAVE FORMED FROM THE PANAMA
COAST TO 10.5N BETWEEN 78W AND 81W...ALSO IN THE ITCZ. ISOLATED
MODERATE SHOWERS AND THUNDERSTORMS ARE ELSEWHERE IN THE
SOUTHWESTERN CORNER OF THE AREA SOUTH OF 13N BETWEEN 82W AND
85W REACHING CENTRAL AMERICA FROM PANAMA TO NICARAGUA.
ANTICYCLONIC FLOW FROM AN UPPER LEVEL RIDGE COVERS THE CENTRAL
CARIBBEAN SEA. MIDDLE TO UPPER LEVEL CYCLONIC FLOW WITH AN
ATLANTIC OCEAN 18N56W CYCLONIC CIRCULATION CENTER REACHES THE
EASTERN CARIBBEAN SEA EAST OF 64W. MIDDLE TO UPPER LEVEL DRY AIR
IS SOUTH OF 16N EAST OF 76W.

THE ATLANTIC OCEAN...
MIDDLE TO UPPER LEVEL TROUGH STRETCHES FROM A CYCLONIC CENTER
NEAR 30N43W TO 24N47W TO AN ATLANTIC OCEAN 18N56W CYCLONIC
CIRCULATION CENTER TO 12N55W. SURFACE TROUGH EXTENDS THROUGH
32N43W TO 27N47W.  THE ONLY SHOWER/THUNDERSTORM ACTIVITY IS
WITHIN 15 TO 30 NM ON EITHER SIDE OF 26N42W 29N40W BEYOND
32N40W. MIDDLE TO UPPER LEVEL DRY AIR IS NORTH OF 16N EAST OF
40W. SURFACE RIDGE RUNS FROM 21N64W TO 24N55W TO BEYOND 32N32W.

$$
MT


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