[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 272338
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT TUE APR 27 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2300 UTC...

...THE ITCZ...
THE ITCZ IS CENTERED FROM SIERRA LEONE NEAR 8N12W ALONG 6N20W
4N30W 3N40W AND INTO NE BRAZIL NEAR 2N52W. NUMEROUS STRONG
CONVECTION IS INLAND OVER SIERRA LEONE. SCATTERED
MODERATE/STRONG CONVECTION IS FROM 5N-8N BETWEEN 15W-20W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 45 NM
EITHER SIDE OF THE AXIS BETWEEN 38W52W.

...DISCUSSION...

THE GULF OF MEXICO...
MUCH OF THE GULF OF MEXICO IS EXPERIENCING GENERALLY FAIR
WEATHER UNDER THE INFLUENCE OF MID AND LOW-LEVEL DRY AND STABLE
AIR. MAINLY ZONAL WLY FLOW ALOFT COVERS THE BASIN DRAWING SOME
UPPER LEVEL MOISTURE ACROSS THE NW GULF SUPPORTING A FEW HIGH
CLOUDS. AN UPPER LEVEL TROUGH TO THE N OVER THE ERN CONUS
CONTINUES TO SUPPORT A DISSIPATING COLD FRONT THAT AS OF 2100
UTC EXTENDS ACROSS NRN FLORIDA FROM N OF JACKSONVILLE TO THE BIG
BEND OF FLORIDA CONTINUING TO NEAR 27N90W. RADAR IMAGERY
INDICATES A LINE OF SHOWERS/THUNDERSTORMS ALONG THE PORTION OF
THE FRONT OVER LAND. THIS FRONT SHOULD CONTINUE TO DISSIPATE AS
A SECOND SURGE OF ENERGY SHOULD MOVE SWIFTLY ACROSS NRN FLORIDA
OVERNIGHT. SURFACE RIDGING IS FORECAST TO BUILD BEHIND IT ACROSS
THE NW GULF EXTENDING FROM HIGH PRESSURE OVER TEXAS KEEPING MUCH
OF THE BASIN UNDER FAIR CONDITIONS.

THE CARIBBEAN SEA...
A STATIONARY FRONT CONTINUES TO LINE THE NW CARIBBEAN FROM WRN
CUBA NEAR 23N80W TO THE YUCATAN PENINSULA AT 20N88W. ISOLATED
SHOWERS ARE WITHIN 45 NM EITHER SIDE OF THE FRONT. A CLUSTER OF
STRONGER SHOWERS/POSSIBLE THUNDERSTORMS ARE OVER THE YUCATAN
PENINSULA FROM 20N-21N BETWEEN 86W-88W. NUMEROUS
SHOWERS/THUNDERSTORMS ARE ALSO ACROSS MUCH OF CENTRAL AMERICA.
THIS MAY BE DUE TO SURFACE CONVERGENCE NEAR THE E PACIFIC ITCZ
WHICH CROSSES OVER COSTA RICO INTO THE SW CARIBBEAN. TOTAL
PRECIPITABLE WATER IMAGERY ALSO INDICATES SIGNIFICANT MOISTURE
ACROSS THE FAR E PACIFIC AND SW CARIBBEAN. THE REMAINDER OF THE
BASIN IS EXPERIENCING GENERALLY FAIR WEATHER UNDER THE INFLUENCE
OF DRY AIR AND SUBSIDENCE ALOFT IN MAINLY ZONAL WLY FLOW.
MODERATE TO FRESH TRADEWINDS ARE ACROSS MUCH OF THE BASIN.
EXPECT THE STATIONARY FRONT TO DISSIPATE DURING THE NEXT 24 HRS.

THE ATLANTIC OCEAN...
A DEEP LAYER TROUGH IMPACTS THE WRN ATLC THIS EVENING WITH A
COLD FRONT ENTERING THE DISCUSSION AREA NEAR 32N71W ALONG 28N74W
ACROSS THE CENTRAL BAHAMAS NEAR 24N76W TO W CUBA WHERE IT
BECOMES STATIONARY ACROSS THE NW CARIBBEAN. A FEW ISOLATED
SHOWERS ARE BETWEEN CUBA AND THE BAHAMAS. HOWEVER...AN UPPER
LEVEL SHORTWAVE TROUGH OVER THE W ATLC SUPPORTING THE FRONTAL
SYSTEM IS PROVIDING DIFFLUENCE ALOFT TO THE E OF THE FRONT
SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS N OF 25N BETWEEN
56W-65W. EXPECT THIS FRONT TO DISSIPATE AS A SECONDARY FRONT
PUSHES INTO THE AREA OVERNIGHT. FARTHER E...A SURFACE RIDGE
DOMINATES ANCHORED BY A 1027 MB HIGH NEAR 34N38W PROVIDING
GENERALLY FAIR WEATHER ACROSS MUCH OF THE REMAINDER OF THE
BASIN. HOWEVER...A STATIONARY FRONT PROTRUDES INTO THE RIDGE
ALONG 32N23W 24N32W 15N44W. SCATTERED SHOWERS ARE WITHIN 45 NM
EITHER SIDE OF THE FRONT. ALOFT...AN UPPER LEVEL RIDGE EXTENDS
FROM THE LESSER ANTILLES TO NEAR 45N38W SUPPORTING THE SURFACE
RIDGE ACROSS THE CENTRAL/E ATLC. AN UPPER LEVEL TROUGH EXTENDS
FROM THE AZORES ISLANDS TO THE NE BRAZIL COAST NEAR 5N51W
SUPPORTING THE STATIONARY FRONT. THIS UPPER LEVEL TROUGH IS MOST
LIKELY ENHANCING CONVECTION ALONG THE ERN PORTION OF THE ATLC
ITCZ.

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

$$
WALTON



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