[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 151103
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SUN JUN 15 2008

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1115 UTC.

...TROPICAL WAVES...

A NEW TROPICAL WAVE APPEARS TO BE ALONG 18.5W FROM 05N TO 13N
BASED ON CYCLONIC TURNING ON THIS MORNINGS VISIBLE SATELLITE
IMAGERY.

A TROPICAL WAVE IS ANALYZED ALONG 33W-34W FROM 06N TO 19N AND
MOVING W AT ESTIMATED 20 KT WITH A CLASSIC INVERTED V CLOUD
PATTERN. DUST IS OBSERVED ON THIS MORNINGS VISIBLE IMAGERY E OF
THE ANALYZED WAVE POSITION. THE WAVE IS CURRENTLY MOVING UNDER
DRY AIR ALOFT...AND THE LARGE AREA OF BROKEN LOW CLOUDS THAT
ACCOMPANIED THE WAVE THE PAST FEW DAYS HAS DIMINISHED
CONSIDERABLY BUT IS STILL EVIDENT WITHIN 120 NM EITHER SIDE OF
OF THE WAVE AXIS FROM 08N-13N.

A TROPICAL WAVE IS ALONG 73W FROM 07N TO 19N MOVING W AT 15-20
KT. BROAD CYCLONIC TURNING CONTINUES ALONG THE WAVE NEAR THE
BORDER OF VENEZUELA AND COLOMBIA. A SMALL CLUSTER OF TSTMS IS
NOTED WITHIN 90 NM OF 17N71W.

...ITCZ...

THE ITCZ AXIS IS ALONG 09N13W TO 05N20W TO 08N34W TO 01S47W.
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN
240 NM N OF THE AXIS BETWEEN 18W AND 26W. SCATTERED MODERATE
ISOLATED STRONG CONVECTION IS NOTED WITHIN 240 NM S OF THE AXIS
BETWEEN 16W AND 28W WITH CYCLONIC TURNING INDICATED AT 06N19.5W
WHICH MAY TURN OUT TO BE THE AXIS OF A NEW TROPICAL WAVE.
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 60
NM EITHER SIDE OF A LINE FROM 09N37W TO 01S45W...AND ELSEWHERE S
OF THE ITCZ TO 03S BETWEEN 34W AND 37W.

...DISCUSSION...

GULF OF MEXICO...
A MID TO UPPER LEVEL CUT OFF CYCLONE IS AT 20.5N96W AND
CONTINUES TO DRIFT WSW WITH TIME. AN UPPER RIDGE EXTENDS N
ACROSS THE YUCATAN PENINSULA AND OVER THE S CENTRAL GULF OF
MEXICO CRESTING AT 23N90W. CLUSTER OF TSTMS WERE ENHANCED
EARLIER NEAR 18N94W WITH THE DEBRIS MOISTURE ADVECTED NE BUT
REMAINING UNDER THE UPPER RIDGE. AN UPPER CYCLONE E OF THE AREA
NEAR THE NW BAHAMAS HAS ITS ENVELOPE CYCLONIC FLOW EXTENDING W
OVER THE EASTERN GULF FROM 29N83W TO 25N83W TO 23N80W. AN UPPER
RIDGE EXTENDS OFF THE TEXAS COAST CRESTING ALONG 29N90W TO
21N97W WITH DRY UPPER AIR INDICATED W OF THE SAME LINE. DRY
UPPER AIR IS ALSO OBSERVED OVER THE CENTRAL GULF BETWEEN 23N AND
27N. OTHERWISE...THE UPPER LEVELS ARE MOIST WITH DENSE MOISTURE
SPREADING S OVER THE GULF WATERS N OF 27N E OF 90W. AT THE LOW
LEVELS A HIGH PRES IS CENTERED NEAR 28N88W. LOCALLY BROKEN LOW
AND MID LEVELS CLOUDS ARE OBSERVED OVER THE GULF WATERS S OF 27N
BETWEEN 89W AND 96W...AND OVER THE NE GULF WATERS.

CARIBBEAN...
AN UPPER CYCLONE NEAR THE NW BAHAMAS HAS AN UPPER TROUGH
EXTENDING SE OVER THE N CARIBBEAN TO A BASE NEAR 17N67W. UPPER
DIFFLUENCE WITHIN THIS TROUGH PROVIDED SUPPORT FOR CONVECTION TO
FLARE ALONG THE NORTHERN EXTENSION OF A TROPICAL WAVE NEAR
17N72W. THE DEBRIS MOISTURE IS NOW ADVECTED NE ACROSS THE
SUBTROPICAL CENTRAL ATLC. TO THE S OF THIS UPPER TROUGH A BROAD
UPPER RIDGE DOMINATES THE CARIBBEAN. DRY UPPER AIR IS INDICATED
OVER THE WATERS FROM 12N TO 17N BETWEEN 80W AND 68W. DEBRIS
MOISTURE ORIGINATING OVER THE YUCATAN PENINSULA AND OVER CENTRAL
AMERICA IS STREAMING E ALONG THE RIDGE OVER THE AREA ELSEWHERE W
OF 78W.

ATLANTIC...
AN UPPER LEVEL CYCLONE IS FILLING NEAR 26N76W BUT CONTINUES TO
TRAIL AN QUASI STATIONARY UPPER TROUGH SE INTO THE NE CARIBBEAN.
INTENSE CONVECTION FLARED OVER THE LARGER N CARIBBEAN ISLANDS
LATE SAT. THE RESULTANT DEBRIS MOISTURE HAS CONCENTRATED IN A
MOISTURE PLUME NOW DISSECTING THE SUBTROPICAL ATLC WITHIN 240 NM
EITHER SIDE OF LINE 19N68W TO 23N55W WHERE THE PLUME NARROWS AND
CONTINUES WELL BEYOND 32N40W. THE SUBTROPICAL CENTRAL ATLC IS
DOMINATED BY THE SOUTHERN END OF A LONGWAVE TROUGH LYING ROUGHLY
N OF POINTS 31N73W 26N58W 31N36W...WITH DRY UPPER AIR INDICATED
WITHIN THIS TROUGH. AN ASSOCIATED COLD FRONT LIES ALONG 31N45W
TO 26N59W TO 28N73W. THE UPPER LEVELS OF THE EASTERN ATLC IS NOW
DOMINATED A BROAD E TO W RIDGE. UPPER DRY AIR IS INDICATED FROM
09N TO 21N BETWEEN 26W AND 36W...AND IS LIKELY RESPONSIBLE FOR
THE LACK OF CONVECTION ALONG THE TROPICAL WAVE IN THE LOWER
LEVELS. LOCALLY BROKEN STRATOCUMULUS IS NOTED OVER EASTERN ATLC
SE OF THE COLD FRONT.

$$
NELSON





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