000
AXNT20 KNHC 151728
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
205 PM EDT THU APR 15 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1645 UTC...

...THE ITCZ...
THE ITCZ AXIS IS CENTERED FROM SRN LIBERIA NEAR 5N8W ALONG 3N20W 
3N30W 3N40W AND INTO NE BRAZIL NEAR EQ50W. SCATTERED 
MODERATE/STRONG CONVECTION IS FROM 1N-5N BETWEEN 7W-15W. SIMILAR 
ACTIVITY IS FROM 1N-5N BETWEEN 28W-32W. NUMEROUS 
MODERATE/SCATTERED STRONG CONVECTION IS ALONG THE NE SOUTH 
AMERICA COASTLINE S OF 10N W OF 50W.

...DISCUSSION...

THE GULF OF MEXICO...
A SURFACE RIDGE CONTINUES TO BUILD ACROSS THE GULF OF MEXICO 
FROM A 1032 MB HIGH OVER N CAROLINA. HOWEVER...A SHORTWAVE UPPER 
LEVEL TROUGH REMAINS OVER THE WRN GULF ENHANCING SCATTERED 
SHOWERS/ISOLATED THUNDERSTORMS IN THE CENTRAL GULF FROM 23N-26N 
BETWEEN 86W-95W. AN UPPER LEVEL RIDGE COVERS THE REMAINDER OF 
THE BASIN WITH AXIS EXTENDING DOWN THE ERN CONUS. A STRONG 
PRESSURE GRADIENT ACROSS THE BASIN IS SUPPORTING MAINLY E WINDS 
OF 20-25 KTS ACROSS THE GULF...REACHING 30 KT ACROSS THE MIDDLE 
AND ERN GULF. EXPECT THE SURFACE RIDGE TO REMAIN AND SHIFT S 
WHILE SHOWERS/THUNDERSTORMS CONTINUE ACROSS THE CENTRAL GULF.
 
THE CARIBBEAN SEA...
SCATTERED SHOWERS CONTINUE TO FALL ACROSS THE NE CARIBBEAN 
ISLANDS WHERE SIGNIFICANT RAINFALL HAS ALREADY FALLEN IN SOME 
AREAS OVER THE PAST SEVERAL DAYS. THIS CONTINUED RAINFALL IS 
ATTRIBUTED TO A DEEP LAYER TROUGH SITUATED OVER THE W ATLC. THE 
ASSOCIATED SURFACE TROUGH EXTENDS FROM NEAR ANTIGUA AND BARBUDA 
AT 18N62W TO NEAR 14N68W. HOWEVER...SCATTERED SHOWERS ARE NOTED 
FARTHER AWAY FROM THE TROUGH ACROSS PUERTO RICO AND NRN 
HISPANIOLA...AS WELL AS WITHIN 90 NM EITHER SIDE OF THE AXIS N 
OF 16N. TOTAL PRECIPITABLE WATER IMAGERY INDICATES ENHANCED 
LOW-LEVEL MOISTURE ACROSS THE LEEWARD ISLANDS WHICH HAS REMAINED 
IN PLACE OVER THE PAST FEW DAYS. SOME OF THIS MOISTURE HAS BEGUN 
TO MOVE NE WITH THE SURFACE FEATURE. SCATTERED SHOWERS/ISOLATED 
THUNDERSTORMS ARE ALSO NOTED ACROSS THE NW CARIBBEAN N OF 85N 
BETWEEN 82W-87W. ALOFT...MAINLY SW FLOW COVERS THE BASIN AROUND 
A BROAD UPPER LEVEL RIDGE CENTERED NE OF S AMERICA. EXPECT THE 
SURFACE TROUGH TO MOVE NE TONIGHT AND TOMORROW DRAWING MOISTURE 
WITH IT.

THE ATLANTIC OCEAN...
THE FAR W ATLC IS INFLUENCED BY A SURFACE RIDGE BUILDING FROM A 
1032 MB HIGH OVER N CAROLINA PROVIDING GENERALLY FAIR WEATHER W 
OF 62W. THE SURFACE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE 
EXTENDING DOWN THE ERN CONUS. A DEEP LAYER TROUGH IMPACTS THE 
CENTRAL ATLC SUPPORTING A 1012 MB LOW N OF THE LESSER ANTILLES 
NEAR 21N61W. A 
SURFACE TROUGH EXTENDS THROUGH THE LOW CENTER FROM THE N TO THE 
LEEWARD ISLANDS ALONG 31N52W 25N55W 23N59W 18N61W CONTINUING 
INTO THE NE CARIBBEAN. SCATTERED SHOWERS ARE WITHIN 150 NM E OF 
THE TROUGH AXIS N OF 25N...AND ALSO FROM 16N-25N BETWEEN 
50W-63W. TOTAL PRECIPITABLE WATER IMAGERY INDICATES SIGNIFICANT 
LOW-LEVEL MOISTURE ASSOCIATED WITH THIS SYSTEM. FARTHER E...A 
WEAK SURFACE RIDGE EXTENDS E OF 48W ANCHORED BY A 1016 MB HIGH 
NEAR THE CAPE VERDE ISLANDS PROVIDING GENERALLY FAIR WEATHER 
ACROSS THE REMAINDER OF THE BASIN. THE RIDGE IS SUPPORTED BY A 
NARROW UPPER LEVEL RIDGE ALONG 40W. AN UPPER LEVEL LOW NEAR 
38N16W CONTINUES TO SUPPORT 989 MB SURFACE LOW NE OF PORTUGAL. 
HOWEVER...NO SIGNIFICANT WEATHER ASSOCIATED WITH THIS SYSTEM 
EXTENDS INTO THE DISCUSSION AREA. ACROSS THE TROPICAL ATLC...A 
BROAD HORIZONTALLY ALIGNED UPPER LEVEL RIDGE EXTENDS ALONG 7N 
FROM THE COAST OF AFRICA TO THE LESSER ANTILLES.

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

$$

WALTON