[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211043 CCA
TWDAT

TROPICAL WEATHER DISCUSSION...COR
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT WED APR 21 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1040 UTC...

...THE ITCZ...

THE ITCZ IS ANALYZED FROM THE COAST OF LIBERIA NEAR
6N10W...WESTWARD ALONG 3N20W 1N30W CONTINUING ALONG THE EQUATOR
LINE TO 52W. WIDELY SCATTERED MODERATE TO STRONG CONVECTION IS
WITHIN 150 NM ON EITHER SIDE OF THE AXIS WEST OF 35W. ISOLATED
PATCHES OF MODERATE TO STRONG CONVECTION ARE WITHIN 80 NM ON
EITHER SIDE OF THE AXIS EAST OF 35W.

...DISCUSSION...

THE GULF OF MEXICO...
AN UPPER LEVEL SHORTWAVE HAS JUST CROSSED THE FLORIDA PENINSULA
LEAVING A DRY AND STABLE AIRMASS ACROSS THE REGION WEST OF 85W.
HOWEVER...WEAK TO MODERATE CONVECTION LINGERS OVER THE STATE OF
FLORIDA AND WITHIN 110 NM WEST OF THE WESTERN COAST OF THE
STATE. THE CONVECTION ASSOCIATED WITH THIS TROUGH IS BETTER
DEPICTED FROM DOPPLER RADAR IMAGERY INDICATING SCATTERED
MODERATE TO HEAVY SHOWERS AND POSSIBLE THUNDERSTORMS FROM 24N TO
32N BETWEEN 80W AND 84W. THIS AREA OF CONVECTION IS EXPECTED TO
MOVE OUT OF THE AREA OF DISCUSSION BY WEDNESDAY LATE MORNING.
HOWEVER...EXPECT INSTABILITY IN THIS REGION WITH SHOWERS
LINGERING THROUGH WEDNESDAY LATE AFTERNOON. FURTHERMORE...THE
SOUTHERN TIP OF A SURFACE TROUGH ENTERS THE FAR NORTHEAST BASIN
NEAR 30N84W CONTINUING SOUTHWEST CROSSING THE FLORIDA PANHANDLE
TO NEAR 28N85W. SCATTERED WEAK TO MODERATE SHOWERS ARE WITHIN 50
NM ON EITHER SIDE OF THE TROUGH. COMPUTER MODELS INDICATED AN
UPPER LEVEL RIDGE OF HIGH PRESSURE BUILDING ACROSS THE REGION
FOR THE REST OF THE WORK WEEK.

THE CARIBBEAN SEA...
WATER VAPOR IMAGERY SHOWS A BROAD AREA OF MID LEVEL MOISTURE
MOVING NORTHEAST ACROSS THE CENTRAL AND EASTERN CARIBBEAN EAST
OF 80W. BEHIND THIS AREA OF MID LEVEL MOISTURE LIES AN UPPER
LEVEL SHORTWAVE THAT SUPPORTS A SURFACE TROUGH THAT ENTERS THE
DISCUSSION ARE THROUGH THE MONA PASSAGE NEAR 18N68W EXTENDING TO
NEAR 14N72W. SCATTERED ISOLATED WEAK SHOWERS ARE WITHIN 30 NM ON
EITHER SIDE OF THE TROUGH...BUT RATHER AFFECTING THE ISLAND OF
HISPANIOLA DUE TO TOPOGRAPHIC EFFECT. MODERATE CONVECTION IS
ALSO FOUND WITHIN 110 NM OFF THE COAST OF PANAMA COLOMBIA AND
VENEZUELA BETWEEN 65W AND 82W. THIS TROUGH IS EXPECTED TO
CONTINUE TO SLOWLY MOVE EASTWARD WITH CONVECTION AFFECTING
MOSTLY THE EASTERN BASIN INCLUDING HISPANIOLA...PUERTO
RICO...AND THE US/UK VIRGIN ISLANDS. COMPUTER MODELS SUGGEST
THIS AREA OF CONVECTION WILL LINGER THROUGH THURSDAY NIGHT.

THE ATLANTIC OCEAN...
WEAK TO MODERATE CONVECTION IS OVER THE FAR WESTERN ATLANTIC
FROM A SURFACE TROUGH ALONG 80W FROM 25N TO 32N. THIS TROUGH IS
SUPPORTED BY AN UPPER LEVEL SHORTWAVE ALIGNED WITH THE SURFACE
TROUGH. FARTHER EAST...AN UPPER LEVEL SHORTWAVE IS MOVING ACROSS
THE CENTRAL ATLANTIC SUPPORTING A COLD FRONT THAT ENTERS THE
DISCUSSION AREA NEAR 32N45W CONTINUING SOUTHWEST ALONG 28N50W
25N58W 25N65W. SHOWERS ARE POSSIBLE WITHIN 120 NM ON EITHER SIDE
OF THE FRONT. TO THE EAST OF THIS FRONT LIES A SURFACE HIGH
PRESSURE SYSTEM NEAR 25N30W DOMINATING THE EASTERN AND PART OF
THE CENTRAL ATLANTIC NORTH OF 18N BETWEEN 20W AND 45W. THIS
SURFACE HIGH IS SUPPORTED BY A BROAD UPPER LEVEL RIDGE THAT
COVERS THE EAST/CENTRAL ATLANTIC FROM 20W TO 50W. A SHEAR
AXIS/REMNANT CLOUD LINE CONTINUES TO GENERATE SCATTERED WEAK TO
MODERATE SHOWERS FROM 14N40W TO 17N52W. COMPUTER MODELS HINT
THIS CONVECTION GENERATED BY THE SHEAR LINE MAY LINGER NEAR THE
MENTIONED AREA THROUGH THURSDAY MORNING. ALSO LOOK FOR MORE
CONVECTION DEVELOPING OVER THE WESTERN ATLANTIC WEST OF 70W AS
THE UPPER LEVEL SHORTWAVE PUSHES THE SURFACE TROUGH ACROSS THIS
REGION.

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

$$

GARCIA




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