[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 170547
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT APR 17 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0550 UTC...

...ITCZ...

FROM THE SOUTHERN COAST OF SIERRA LEONE NEAR 7N12W...WESTWARD
ALONG 5N20W 4.5N30W 3N40W EQ50W. ISOLATED MODERATE CONVECTION IS
WITHIN 100 NM EITHER SIDE OF THE AXIS BETWEEN 20W AND 40W.

...DISCUSSION...

GULF OF MEXICO...
A 1021 MB SURFACE HIGH OVER THE FAR WESTERN ATLANTIC CONTINUES
TO INFLUENCE THE WEATHER OVER THE EASTERN GULF EAST OF 90W.
FURTHERMORE...A 1020 MB HIGH IS ALSO CENTERED OVER THE FLORIDA
PANHANDLE RESULTING IN EAST TO SOUTHEAST SURFACE FLOW OVER THE
GULF NORTH OF 24N. THE HIGH OVER THE PANHANDLE IS FORECAST TO
MERGE WITH THE WESTERN ATLANTIC HIGH AND CONTINUE TO MOVE
EASTWARD BY LATE SATURDAY...AS A WEAK FRONTAL BOUNDARY SKIRTS
THE NORTHERN WATERS AND COASTAL PLAIN. WATER VAPOR IMAGERY SHOWS
AN UPPER LEVEL SHORTWAVE OVER THE FAR SOUTHWEST BASIN SUPPORTING
A MID LEVEL LOW SPINNING NEAR 20N92W. AT SURFACE NEAR THE SAME
AREA...A SURFACE TROUGH IS ANALYZED OVER THE SOUTHWEST BASIN
FROM 26N96W 21N95W 19N91W. THIS SYSTEM IS CREATING NUMEROUS
SHOWERS AND SCATTERED TSTMS OVER THE AREA FROM 20N-25N BETWEEN
85W-95W. AS THIS UPPER LEVEL FEATURE MOVES EASTWARD THROUGH THE
WEEKEND...EXPECT A WEAK LOW OR FRONTAL TROUGH TO DEVELOP OVER
THE SE GULF AND WESTERN CUBA BY LATE SUNDAY.

CARIBBEAN SEA...
AN UPPER LEVEL SHORTWAVE IS NEAR THE WESTERN YUCATAN PENINSULA
SUPPORTING A MID LEVEL LOW SPINNING NEAR 20N92W. THIS FEATURE IS
SUPPORTING NUMEROUS SHOWERS AND SCATTERED TSTMS OVER THE FAR
NORTHWEST NORTH OF 17N WEST OF 82W. COMPUTER MODELS INDICATE
THIS AREA OF CONVECTION WILL MOVE EASTWARD AFFECTING THE WESTERN
CARIBBEAN WEST OF 78W. ELSEWHERE ACROSS THE CENTRAL AND EASTERN
BASIN...A SURFACE TROUGH ENTERS THE FAR SOUTHEAST CORNER OF THE
BASIN NEAR SAINT VINCENT EXTENDING TO CUMANA VENEZUELA. SHOWERS
ARE WITHIN 90 NM ON EITHER SIDE OF THE TROUGH. NORTHEAST WINDS
OVER THE NORTH-NORTHEAST BASIN ARE CONTINUE TO FEED ATLANTIC
MOISTURE AND ISOLATED SHOWERS OVER PUERTO RICO AND HISPANIOLA.
THE REMAINDER OF THE BASIN IS EXPERIENCING TRADES IN THE 15 TO
20 KT RANGE THIS EVENING UNDER GENERALLY FAIR SKIES.

ATLANTIC OCEAN...
A 1021 MB SURFACE HIGH OVER THE FAR WESTERN ATLANTIC NEAR 29N73W
CONTINUES TO BRING FAIR WEATHER WEST OF 64W. HOWEVER...A FEW
ISOLATED SHOWERS EMBEDDED WITHIN EASTERLY FLOW CONTINUE TO
IMPACT THE CENTRAL AND NORTHERN BAHAMAS AS WELL AS PORTIONS OF
THE SOUTHERN FLORIDA PENINSULA. BROAD AND ELONGATED SUBTROPICAL
JET STREAM FLATTENS ACROSS THE ATLANTIC WITH CENTRAL AXIS ALONG
26N. WITHIN THIS UPPER LEVEL FEATURE LIES A STRONG JETSTREAM
COVERING THE WESTERN AND CENTRAL ATLANTIC FROM 34W TO 75W ALONG
THE SAME LATITUDE AXIS. THIS FEATURE IS ENHANCING AN UPPER LEVEL
LOW NEAR 35N45W. THE UPPER LEVEL LOW SUPPORTS A PAIR OF SURFACE
LOW PRESSURE SYSTEMS NEAR 35N48W AND 38N44W. SURFACE BOUNDARIES
FROM THESE TWO SURFACE LOWS EXTEND INTO THE DISCUSSION AREA. A
COLD FRONT ENTERS NEAR 32N38W TO A WEAK 1010 MB LOW CENTERED
NEAR 23N44W. THEN...IT CONTINUES TO NEAR 17N54W...WHERE IT
BECOMES A SURFACE TROUGH THAT EXTENDS TO THE FAR SOUTHEAST
CORNER OF THE CARIBBEAN SEA. SCATTERED SHOWERS ARE WITHIN 200 NM
EAST OF THE COLD FRONT AND WITHIN 200 NM EITHER SIDE OF THE
SURFACE TROUGH. A SECONDARY SURFACE TROUGH IS NW OF THE LEADING
COLD FRONT AND EXTENDS FROM 30N44W TO 25N63W. ISOLATED SHOWERS
ARE WITHIN 60 NM EITHER SIDE OF THE BOUNDARY. FARTHER EAST...A
1018 MB HIGH IS CENTERED NEAR 25N27W AND EXTENDS SURFACE RIDGING
AND GENERALLY FAIR WEATHER OVER THE REMAINDER OF THE EASTERN
ATLC...INCLUDING THE CAPE VERDE ISLANDS.

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

$$

GARCIA


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