[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201101
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI APR 20 2007

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...METEOROLOGICAL
ANALYSIS...WEATHER OBSERVATIONS...AND RADAR.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1015 UTC.

...THE ITCZ...
8N10W 3N20W 1N30W 1N40W...CROSSING THE EQUATOR AT 50W...GOING
INTO NORTHEASTERN BRAZIL NEAR 1S52W. WIDELY SCATTERED MODERATE
SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE SOUTH OF 2N6W
3N11W 6N18W 4N30W 3N40W 2N48W 2N51W.

...DISCUSSION...

THE GULF OF MEXICO...
AN UPPER LEVEL RIDGE EXTENDS FROM THE YUCATAN PENINSULA BEYOND
THE NORTHWESTERN CORNER OF THE AREA...INTO NORTH TEXAS. AN UPPER
LEVEL RIDGE ALSO RUNS FROM NORTHERN COLOMBIA/EXTREME NORTHWESTERN
VENEZUELA TOWARD THE NORTHWEST CORNER OF THE CARIBBEAN SEA...TO
THE YUCATAN PENINSULA. IT IS POSSIBLE THAT THIS WHOLE AREA
OF UPPER LEVEL ANTICYCLONIC FLOW IS PART OF THE SAME SYSTEM.
UPPER LEVEL MOISTURE IS WITHIN 400 NM ON EITHER SIDE OF 24N90W
BEYOND 32N95W. WEAK SURFACE HIGH PRESSURE IS BUILDING FROM
NORTHWEST-TO-SOUTHEAST ACROSS THE GULF OF MEXICO. THE SURFACE
PRESSURE GRADIENT REMAINS WEAK IN THE AREA. BROKEN MIDDLE TO
HIGH CLOUDS ARE STREAMING NORTHEASTWARD FROM MEXICO INTO
TEXAS...AND INTO THE GULF OF MEXICO WITHIN 200 NM TO 250 NM ON
EITHER SIDE OF 19N103W 25N99W BEYOND 31N96W.

THE CARIBBEAN SEA...
AN UPPER LEVEL RIDGE ALSO RUNS FROM NORTHERN COLOMBIA/EXTREME
NORTHWESTERN VENEZUELA TOWARD THE NORTHWEST CORNER OF THE
CARIBBEAN SEA...TO THE YUCATAN PENINSULA. AN UPPER LEVEL RIDGE
EXTENDS FROM THE YUCATAN PENINSULA BEYOND THE NORTHWESTERN
CORNER OF THE GULF OF MEXICO...INTO NORTH TEXAS. IT IS POSSIBLE
THAT THIS WHOLE AREA OF UPPER LEVEL ANTICYCLONIC FLOW IS PART OF
THE SAME SYSTEM. THE ATLANTIC OCEAN-TO-CARIBBEAN SEA COLD FRONT
GOES FROM THE BAHAMAS NEAR 23N75W TO 22N77W. THE COLD FRONT IS
DISSIPATING FROM 22N77W TO 22N78W TO 20N83W TO THE YUCATAN
PENINSULA NEAR 19N87W. A SURFACE RIDGE IS ALONG 20N50W TO
15N62W JUST WEST OF THE EASTERN CARIBBEAN SEA ISLANDS.
NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE IN EXTREME
NORTHWESTERN VENEZUELA AND NORTHEASTERN COLOMBIA FROM 8N TO
10N BETWEEN 70W AND 74W. THE EARLIER PRECIPITATION IN COASTAL
COLOMBIA HAS DISSIPATED...AND OTHER STRONG SHOWERS AND
THUNDERSTORMS NOW HAVE DEVELOPED IN THE COASTAL SECTIONS TO THE
SOUTH OF THE AREA FROM SIX HOURS AGO...FROM 4N TO 7N BETWEEN 76W
AND 78W. CONVECTIVE DEBRIS CLOUDS...WITH SOME ISOLATED MODERATE
SHOWERS...ARE SOUTH OF 10N BETWEEN 75W AND 78W...INCLUDING IN
THE GULF OF URABA.

THE ATLANTIC OCEAN...
DEEP LAYER CYCLONIC FLOW COVERS THE AREA NORTH OF 20N WEST OF
40W. THIS SYSTEM SUPPORTS AN ATLANTIC OCEAN COLD FRONT THAT
GOES FROM A 1001 MB 31N64W LOW PRESSURE CENTER TO 25N70W...
TO THE BAHAMAS NEAR 22N77W. THE COLD FRONT DISSIPATES FROM
22N77W TO 22N78W TO 20N83W TO THE YUCATAN PENINSULA NEAR 19N83W.
SOUTHWESTWARD TO CUBA NEAR 23N80W AND CUBA NEAR 22N83W.
SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE
FROM 25N TO 27N BETWEEN 52W AND 56W. ISOLATED MODERATE SHOWERS
AND POSSIBLE THUNDERSTORMS ARE ELSEWHERE FROM 22N TO 30N BETWEEN
50W AND 60W...AND FROM 25N TO BEYOND 32N BETWEEN 37W AND 43W.
SHOWERS AND THUNDERSTORMS ALSO ARE POSSIBLE FROM 28N TO 36N
BETWEEN 54W AND 60W...EAST OF THE 1001 MB SURFACE LOW PRESSURE
CENTER. A SURFACE RIDGE STARTS AT A 1022 MB HIGH PRESSURE CENTER
NEAR 33N30W AND IT CONTINUES TO 28N38W 20N50W AND 15N62W IN THE
EASTERN CARIBBEAN SEA. AN UPPER LEVEL TROUGH IS IN THE
TROPICAL JET STREAM. BROAD WESTERLY FLOW FROM VENEZUELA AND
GUYANA/SURINAME/AND FRENCH GUIANA TO 3N45W...TO THE CAPE VERDE
ISLANDS...ACROSS AND BEYOND THE WESTERN SAHARA. MIDDLE TO UPPER
LEVEL DRY AIR/SUBSIDENCE IS WITHIN 300 NM TO 600 NM BETWEEN 30W
AND 54W.

$$
MT


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