[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 262344
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI APR 26 2013

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE COAST OF SIERRA LEONE NEAR
7N12W TO 4N20W. THE ITCZ BEGINS NEAR 4N20W AND CONTINUES ALONG
3N33W 2N41W. SCATTERED MODERATE CONVECTION IS FROM EQ-4N BETWEEN
2W-6W...AND FROM EQ-1N BETWEEN 15W-17W. A CLUSTER OF NUMEROUS
STRONG CONVECTION IS MOVING OFF THE COAST OF AFRICA FROM 4N-7N
BETWEEN 9W-11W.

...DISCUSSION...

GULF OF MEXICO...
BROAD UPPER LEVEL RIDGING REMAINS ACROSS THE GULF OF MEXICO
SUPPORTING SURFACE RIDGING ACROSS THE AREA EXTENDING FROM A 1032
MB HIGH CENTERED OVER WEST VIRGINIA. EAST TO SOUTHEAST SURFACE
WINDS OF 10-15 KT ARE AROUND THE RIDGE ALONG WITH MOSTLY CLEAR
SKIES. A WEAK SURFACE TROUGH PARALLELS THE MEXICAN COAST ALONG
22N97W TO 18N94W. POSSIBLE ISOLATED SHOWERS ARE UP TO 60 NM EAST
OF THE AXIS. LITTLE CHANGE IS EXPECTED OVER THE NEXT 24 HOURS AS
SURFACE RIDGING REMAINS THE DOMINANT FEATURE.

CARIBBEAN SEA...
BROAD UPPER RIDGING ACROSS THE GULF OF MEXICO SPILLS OVER INTO
THE WESTERN CARIBBEAN ACCOMPANIED BY DRY AIR ALOFT. THE DRY AIR
CONTINUES ACROSS THE CENTRAL AND EASTERN CARIBBEAN WRAPPING
AROUND AN UPPER LEVEL TROUGH EXTENDING FROM THE ATLC ALONG 60W
INTO THE FAR EASTERN CARIBBEAN. THE DRY AIR IS PROVIDING MOSTLY
FAIR CONDITIONS AT THE SURFACE WITH ONLY A FEW PATCHES OF
POSSIBLE ISOLATED SHOWERS OVER CENTRAL HISPANIOLA AS WELL AS
ACROSS HONDURAS AND NICARAGUA. ISOLATED SHOWERS ARE ALSO IN THE
FAR SE CORNER OF THE BASIN. A MUCH LARGER AREA OF SCATTERED
SHOWERS IS EAST OF THE WINDWARD ISLANDS ASSOCIATED WITH MOIST
SOUTHWESTERLY FLOW ALOFT AROUND THE UPPER TROUGH. THIS AREA OF
MOIST CONDITIONS EAST OF THE ISLANDS MAY DRIFT WEST OVER THE
WEEKEND POSSIBLY BRINGING HEAVY RAINFALL TO SOME OF THE WINDWARD
ISLANDS. ELSEWHERE ACROSS THE BASIN...TRADEWIND FLOW OF 10-15 KT
DOMINATES WITH A SMALL AREA OF 20 KT WINDS FOCUSED NORTH OF
COLOMBIA.

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH EXTENDS OFF THE EASTERN SEABOARD ALONG 68W
SUPPORTING A COLD FRONT THAT ENTERS THE AREA ALONG 32N74W
30N81W. THE FRONT IS MAINLY DRY...HOWEVER...A SURFACE TROUGH IS
TO THE EAST ALONG 32N68W TO 28N75W WITH SCATTERED
SHOWERS/POSSIBLE THUNDERSTORMS TO THE EAST NORTH OF 29N BETWEEN
64W-67W. AN INVERTED SURFACE TROUGH IS TO THE SOUTH ALONG 27N69W
TO 20N67W. POSSIBLE ISOLATED SHOWERS ARE WITHIN 100 NM TO THE
EAST. BROAD UPPER TROUGH CONTINUES INTO THE CENTRAL ATLC ALONG
60W. HOWEVER...AN UPPER LEVEL RIDGE EXTENDS TO THE NORTH OF THE
AREA ALONG 55W SUPPORTING A SURFACE RIDGE WITH AXIS CONTINUING
INTO THE AREA ALONG 58W. AN UPPER LEVEL LOW NEAR 36N33W
CONTINUES TO SUPPORT A SURFACE LOW NORTH OF THE DISCUSSION AREA.
AN ASSOCIATED COLD FRONT ENTERS THE AREA NEAR 32N27W AND
CONTINUES ALONG 25N33W 24N43W 26N49W. POSSIBLE ISOLATED SHOWERS
ARE WITHIN 60 NM TO EITHER SIDE. A SURFACE TROUGH IS EAST OF THE
FRONT ALONG 31N22W 25N26W 19N34W WITH NO ASSOCIATED SHOWERS.
BROAD UPPER RIDGING COVERS THE MAJORITY OF THE TROPICAL ATLC
PROVIDING GENERALLY FAIR WEATHER ACROSS THE REMAINDER OF THE
EAST ATLC.

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

$$
WALTON


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