[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 301749
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI APR 30 2010

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1745 UTC...

...THE ITCZ...

THE ITCZ IS CENTERED FROM THE CENTRAL LIBERIA COAST NEAR 6N10W
WESTWARD ALONG 5N20W 4.5N30W 4N40W INTO THE NORTHEASTERN COAST
OF BRAZIL NEAR 3N51W. SCATTERED MODERATE TO STRONG CONVECTION IS
IN THE COASTAL WATERS OF AFRICA FROM THE WESTERN COAST OF COTE
D'VOIRE...CONTINUING ALONG COASTS OF LIBERIA AND SIERRA LEONE.
MODERATE TO STRONG CONVECTION IS WITHIN 100 NM EITHER SIDE OF
THE AXIS BETWEEN 13W AND 18W. SIMILAR CONVECTION IS BETWEEN 28W
AND 34W. ELSEWHERE WEST OF 34W...SCATTERED MODERATE TO STRONG
CONVECTION IS WITHIN 90 NM NORTH OF THE AXIS.

...DISCUSSION...

THE GULF OF MEXICO...
MARINE OBSERVATIONS SHOW SOUTHERLY WINDS 10 KT TO 20 KT ACROSS
THE BASIN. WATER VAPOR IMAGERY SHOWS STRONG SUBSIDENCE OF DRY
AIR SUPPRESSING ANY AREAS OF DEEP CONVECTION ACROSS THE
BASIN...WITH THE STRONGEST EFFECT SOUTH OF 27W. THE DRY STABLE
AIRMASS WILL BE IN PLACE FOR THE NEXT 12 TO 18 HOURS. IN THE
MEAN TIME...AN UPPER LEVEL TROUGH OF LOW PRESSURE SWINGS BY THE
FAR NORTHERN GULF COAST PROVIDING ENOUGH INSTABILITY TO PRODUCE
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 50 NM ALONG
THE COASTS OF LOUISIANA MISSISSIPPI ALABAMA AND THE FLORIDA
PANHANDLE. LONG RANGE MODELS INDICATE SOME CONVECTION MAY MOVE
ACROSS THE NORTHERN GULF COAST...LINKED TO THE SOUTHERN TIP OF
A FAIRLY STRONG COLD FRONT ASSOCIATED WITH THE UPPER LEVEL
TROUGH...THROUGHOUT THE WEEKEND AND THE BEGINNING OF NEXT WEEK.

THE CARIBBEAN SEA...
ABUNDANT MID TO UPPER LEVEL MOISTURE FROM CENTRAL AMERICA AND
EASTERN TROPICAL PACIFIC CONTINUES TO AFFECT THE SOUTHWESTERN
CORNER OF THE BASIN WEST OF 75W SOUTH OF 16N. FURTHERMORE...PART
OF THE ITCZ IS OVER NORTHWEST COLOMBIA...PANAMA... AND COSTA
RICA...AFFECTING THE WATERS NEAR THE COAST OF THESE COUNTRIES
INCLUDING NICARAGUA AND EASTERN HONDURAS. COMPUTER MODELS
CONTINUE TO SHOW CONVECTION IN THIS REGION OVER THE NEXT 24
HOURS. ELSEWHERE ACROSS THE CARIBBEAN SEA...FAIR WEATHER IS
OBSERVED ACROSS THIS REGION WITH LIGHT TO MODERATE TRADE WINDS.

THE ATLANTIC OCEAN...
AN UPPER LEVEL RIDGE OF HIGH PRESSURE IS OVER THE WESTERN
ATLANTIC. THE SURFACE HIGH PRESSURE SYSTEM IS NEAR 29N67W.
FURTHER EAST INTO THE CENTRAL ATLANTIC...A COLD FRONT ENTERS THE
AREA OF DISCUSSION EXTENDING WEST-SOUTHWEST ALONG 32N43W 25N50W
22N60W BECOMING A STATIONARY THROUGH 21N68W. MODERATE CONVECTION
IS WITHIN 90 NM ON EITHER SIDE OF THE COLD FRONT AND 60 NM ON
EITHER SIDE OF THE STATIONARY FRONT. THIS FRONTAL SYSTEM IS
SUPPORTED BY A BROAD UPPER LEVEL SHORTWAVE TROUGH THAT SWINGS BY
THE CENTRAL ATLANTIC. ANTI-CYCLONIC FLOW COVERS MOST OF THE
EASTERN ATLANTIC SUPPRESSING DEEP CONVECTION OVER MOST OF THE
EASTERN REGION. THE STRONGEST AREA OF SURFACE HIGH PRESSURE IS
NEAR 37N25W. COMPUTER MODELS INDICATE THE COLD FRONT WILL
CONTINUE TO MOVE EASTWARD WITH CONVECTION AHEAD OF IT.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$

GARCIA


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