[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 262343
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT WED APR 26 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 4N9W 1N22W 2N51W. SCATTERED MODERATE
AND ISOLATED STRONG CONVECTION IS NOTED WITHIN 240 NM EITHER
SIDE OF THE AXIS E OF 17W AND WITHIN 300 NM OF AXIS W OF 17W.

...DISCUSSION...
GULF OF MEXICO...
A SHORTWAVE RIDGE HAS SHIFTED SE OF THE AREA BUT ITS
ANTICYCLONIC FLOW STILLS COVERS THE SE GULF WATERS ALOFT. A BAND
OF DRY UPPER AIR IS INDICATED WITHIN 90 NM EITHER SIDE OF LINE
26N80W 18N91W. AN UPPER ANTICYCLONE IS OVER OLD MEXICO NEAR
17N106W. THE ENVELOPE OF ITS ANTICYCLONIC FLOW COVERS THE GULF
WATERS W OF 88W ADVECTING UPPER MOISTURE ALONG ITS EASTERN
FRINGES. A SHORTWAVE TROUGH IS MOVING THROUGH THE NORTHERN
WATERS WITH ITS AXIS CURRENTLY ALONG 32N93W 29N96W. THE
ASSOCIATED SURFACE COLD FRONT EXTENDS FROM 31N90W TO 26N96W THEN
BECOMES ILL DEFINED AS IT LIES NW ALONG THE E SLOPE OF MEXICAN
MOUNTAINS TO NEAR 29N102W. AN OUTFLOW BOUNDARY HAS MOVED SE OVER
THE N CENTRAL GULF WATERS. DEBRIS MOISTURE FROM THIS CONVECTION
IS SPREADING GENERALLY NE IN RESPONSE TO THE PARENT UPPER
TROUGH...ROUGHLY COVERING THE WATERS N OF 26N E OF 88W.

CARIBBEAN SEA...
ALOFT...A SHORTWAVE RIDGE ORIGINATING FROM AN UPPER ANTICYCLONE
NEAR 6N66W...EXTENDS NW ALONG 11N72W TO 20N83W. ANTICYCLONIC
FLOW DOMINATES THE UPPER LEVELS OF THE CARIBBEAN W OF 66W
WHERE THE FLOW BECOMES NEARLY ZONAL. DEBRIS MOISTURE FROM
CONVECTION S OF 11N BETWEEN 72W AND 83W CONTINUES TO SPREAD NE
ALONG THE PERIPHERY OF THE RIDGE WITH DRY UPPER AIR INDICATED
ALONG 15N E OF 74W.

ATLANTIC OCEAN...
A SHORTWAVE RIDGE EXTENDS N FROM THE CARIBBEAN ALONG 70W WITH
ANTICYCLONIC FLOW COVERING THE WATERS S OF 27N W OF 62W WHERE
THE UPPER FLOW THEN TURNS CYCLONIC INTO A LONGWAVE TROUGH OVER
THE CENTRAL ATLC WITH AXIS N TO S ALONG 50W. UPPER MOISTURE IS
SPREADING E OFF THE N FLORIDA COAST N OF 29N TO NEAR 70W ATTM.
AN EMBEDDED UPPER CYCLONE IS OBSERVED NEAR 29N45W AND SHIFTING
NE WITH TIME. AT THE LOW LEVELS...A STATIONARY FRONT IS
DISSIPATING ALONG 32N31W 27N42W 21N60W. OVERCAST MULTILAYERED
CLOUDS AND SCATTERED SHOWERS ARE NOTED WITHIN 90 NM OF THE
DECAYING FRONT. A SURFACE HIGH 1023 MB IS NEAR 34N48W WITH A
RIDGE EXTENDING SW TO THE STRAITS OF FLORIDA. E OF THE FRONT...
A RIDGE EXTENDS SW ALONG 32N25W 21N46W.

THE E ATLC IS DOMINATED ALOFT BY A LONGWAVE TROUGH WITH AN
EMBEDDED CYCLONE NEAR 32N5E TRAILING A TROUGH SW ALONG 25N7W TO
14N21W. ANOTHER CYCLONE IS WELL N OF THE AREA NEAR 41N34W WITH A
TROUGH EXTENDING S ALONG 32N35W 26N35W. BETWEEN THE TWO CYCLONES
AN ANTICYCLONE IS NEAR 34N14W. A BAND OF DRY UPPER AIR IS NOTED
WITHIN 540 NM EITHER SIDE OF LINE 27N6W 12N28W. A BROAD UPPER
ANTICYCLONE IS NOTED OVER AFRICA NEAR 12N17E WITH A RIDGE
EXTENDING W OFF THE W AFRICAN COAST AT 6N12W. ASSOCIATED UPPER
DIFFLUENCE IS ENHANCING ITCZ CONVECTION E OF 16W.

$$
NELSON



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