[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 190546
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI APR 19 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 10N15W TO
06N20W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
06N20W TO 05N30W TO THE EQUATOR NEAR 45W. SCATTERED MODERATE
CONVECTION IS FROM 03N-05N BETWEEN 06W-10W. ISOLATED MODERATE
CONVECTION IS WITHIN 60 NM EITHER SIDE OF A LINE FROM 04N31W TO
04N45W.

...DISCUSSION...

GULF OF MEXICO...
A VIGOROUS MIDDLE TO UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR
IMAGERY OVER THE UPPER MISSISSIPPI RIVER VALLEY AND CENTRAL
PLAINS THAT SUPPORTS A COLD FRONT ANALYZED INTO THE NW GULF NEAR
30N93W SW TO 27N95W TO THE NE MEXICO COAST NEAR 25N98W. MOSAIC
DOPPLER RADAR AND LIGHTNING DATA INDICATES WIDELY SCATTERED
SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 75 NM EITHER
SIDE OF THE FRONT. EAST OF THE FRONT...SOUTH-SOUTHEASTERLY WINDS
IN THE RANGE OF 10 TO 20 KT ARE FOUND ON THE SOUTHWESTERN
PERIPHERY OF A SURFACE RIDGE ANCHORED OVER THE WESTERN NORTH
ATLC. SKIES REMAIN GENERALLY CLEAR THIS EVENING AS WELL S OF 22N
AND E OF 90W. NW OF THE COLD FRONT...STRONG NORTHERLY WINDS ARE
OCCURRING AND FORECAST TO SPREAD SOUTH AND EAST THROUGH SATURDAY
AS HIGH PRESSURE BUILDS IN FROM THE SOUTHERN PLAINS TO THE GULF
COAST.

CARIBBEAN SEA...
CONDITIONS REMAIN TRANQUIL OVERALL THIS EVENING ACROSS MUCH OF
THE CARIBBEAN BASIN AS DRY AIR AND SUBSIDENCE IS NOTED ON WATER
VAPOR IMAGERY N OF 12N. SCATTERED TO BROKEN CONVECTIVE DEBRIS
MIDDLE TO UPPER LEVEL CLOUDINESS CONTINUES TO STREAM NE
ORIGINATING OVER THE SOUTH AMERICAN CONTINENT. ELSEWHERE...SKIES
REMAIN CLEAR WITH ONLY A FEW ISOLATED SHOWERS NOTED ON SATELLITE
IMAGERY OCCURRING ACROSS THE LESSER ANTILLES AND PORTIONS OF THE
NE CARIBBEAN NORTHEAST OF A LINE FROM SAINT LUCIA TO WESTERN
HISPANIOLA NEAR 18N74W. TRADES PERSIST AND WILL REMAIN QUITE
BRISK THROUGH THE OVERNIGHT HOURS GENERALLY IN THE RANGE OF 15
TO 25 KT AS A RIDGE AND ASSOCIATED STRONG PRESSURE GRADIENT IS
ANCHORED OVER THE SW NORTH ATLC. THIS OVERALL SYNOPTIC PATTERN
IS EXPECTED TO PERSIST THROUGH THE WEEKEND WITH THE RIDGE TO THE
NORTH WEAKENING GRADUALLY AND TRADES RELAXING BY EARLY SUNDAY AS
A RESULT.

ATLANTIC OCEAN...
A DOME OF DRY AND SUBSIDENT MIDDLE TO UPPER LEVEL AIR IS NOTED
ON WATER VAPOR IMAGERY OVER THE SW NORTH ATLC THAT IS PROVIDING
FOR OVERALL CLEAR SKIES AND FAIR CONDITIONS THIS EVENING. LATEST
SURFACE ANALYSIS SHOWS A RIDGE REMAINS ANCHORED OVER THE WESTERN
NORTH ATLC BY A 1033 MB HIGH CENTERED SE OF NOVA SCOTIA NEAR
42N60W. THE ONLY FEATURE TO HIGHLIGHT IS A WEAK SURFACE TROUGH
EMBEDDED WITHIN THE SOUTHERN PERIPHERY OF THE RIDGE ANALYZED
FROM 25N57W TO 30N54W. POSSIBLE ISOLATED SHOWERS ARE NOTED IN
THE VICINITY OF THE TROUGH AXIS FROM 24N-30N BETWEEN 53W-61W.
FARTHER EAST...A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM
37N45W TO 20N55W AND SUPPORTS A WEAK 1020 MB LOW CENTERED NEAR
36N39W AND AN ASSOCIATED COLD FRONT FROM 37N37W TO 32N38W TO
29N40W. ISOLATED SHOWERS AND TSTMS ARE OCCURRING WITHIN 180 NM
EAST OF THE COLD FRONT AS THE LOW CONTINUES TO MOVE NE AND WELL
NORTH OF THE DISCUSSION AREA IN 12 TO 24 HOURS. THE REMAINDER OF
THE EASTERN ATLC IS UNDER THE INFLUENCE OF WEAK SURFACE RIDGING
WITH NORTHEASTERLY TRADES S OF 30N IN THE RANGE OF 10 TO 20 KT.

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

$$
HUFFMAN


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