000 AXNT20 KNHC 281020 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN APR 28 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0955 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS THE COAST OF LIBERIA NEAR 6N10W TO 1N14W. THE ITCZ BEGINS NEAR 1N14W AND CONTINUES ALONG EQ20W EQ30W 1S40W TO 2S42W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-7N BETWEEN 17W-30W. SCATTERED MODERATE CONVECTION IS FROM 8S-3N BETWEEN 31W-50W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL RIDGING CONTINUES TO COVER MOST OF THE GULF SUPPORTING SURFACE RIDGING EXTENDING FROM A 1028 MB HIGH NEAR 40N70W. THIS PATTERN IS PROVIDING EAST TO SOUTHEAST SURFACE FLOW OF 10-15 KT N OF 22N. A FRONTAL SYSTEM EXTENDING ACROSS MISSISSIPPI...CENTRAL LOUISIANA AND EASTERN TEXAS IS GENERATING NUMEROUS HEAVY RAINSHOWERS WITH ISOLATED THUNDERSTORMS WITHIN 120 NM OFF THE TEXAS COASTLINE. IN THE SOUTHERN GULF...A SURFACE TROUGH EXTENDS FROM 21N92W 18N93W THEN INLAND TO 16N93W. NO RAINSHOWERS ACTIVITY HAS BEEN REPORTED/OBSERVED ASSOCIATED TO THIS TROUGH. OVER THE COURSE OF 24 HOURS...THE FRONT INLAND WILL LIKELY EXTEND A TROUGH INTO THE N GULF THUS ENHANCING RAINSHOWERS/THUNDERSTORMS ALONG THE NORTHERN GULF COAST. CARIBBEAN SEA... A BROAD UPPER LEVEL TROUGH WITH AXIS CROSSING LA HISPANIOLA COVERS THE ENTIRE CARIBBEAN. MOSTLY DRY AIR ALOFT IS PROVIDING FAIR SURFACE WEATHER CONDITIONS WITH CLEAR SKIES EXCEPT FOR A FEW PATCHES OF LOW LEVEL CLOUDS PRODUCING ISOLATED SHOWERS WITHIN 100 NM SOUTH OF THE GREATER ANTILLES. A FEW PATCHES OF CLOUDS WITH POSSIBLE ISOLATED SHOWERS ARE ALSO FROM 17N-20N BETWEEN 83W-87W. A LARGE AREA OF RAINSHOWERS CONTINUES EAST OF THE WINDWARD ISLANDS. MODEL GUIDANCE CONTINUES TO SHOW A GRADUAL SHIFT TO THE WEST OF THIS MOISTURE WITHIN THE NEXT 24 HOURS WHICH MAY CONTINUE TO PRODUCE HEAVY RAINSHOWERS AND THUNDERSTORMS TO THE LESSER ANTILLES IN THE SE CARIBBEAN. TRADEWIND FLOW OF 10-15 KT SPREADS ACROSS THE MAJORITY OF THE BASIN WITH WINDS UP TO 20 KT ALONG THE COAST OF COLOMBIA. ATLANTIC OCEAN... UPPER LEVEL RIDGING OVER THE SE CONUS SUPPORTS SURFACE RIDGING ACROSS THE WEST ATLC ANCHORED BY A 1028 MB HIGH NEAR 40N70W. A NARROW UPPER LEVEL TROUGH TO THE EAST WITH AXIS NEAR 62W SUPPORTS A FRONTAL SYSTEM NORTH OF THE AREA WHICH TAIL TRANSITIONS INTO A SURFACE TROUGH EXTENDING ALONG 30N62W TO 26N64W. THE SAME UPPER LEVEL NARROW ELONGATED TROUGH SUPPORTS A SECOND SURFACE TROUGH ALONG 30N58W TO 26N56W WITH POSSIBLE ISOLATED SHOWERS WITHIN 120 NM EAST OF THE AXIS. A LARGE AREA OF SHOWERS/POSSIBLE THUNDERSTORMS ARE SE OF THE WINDWARD ISLANDS FROM 7N-13N BETWEEN 53W-62W. THE ACTIVITY IS LIKELY LINKED TO MOIST SOUTHWESTERLY FLOW ALOFT AROUND THE WESTERN PERIPHERY OF A BROAD UPPER RIDGE ANCHORED BY A HIGH N OF THE BRAZILIAN COAST NEAR 7N39W. FARTHER NORTH...AN UPPER LEVEL LOW NEAR 37N40W CONTINUES TO SUPPORT 1004 MB SURFACE LOW NEAR 36N39W. A SURFACE TROUGH ASSOCIATED TO THAT LOW EXTENDS INTO THE DISCUSSION AREA ALONG 30N26W TO 25N26W. POSSIBLE ISOLATED SHOWERS ARE ALONG THE TROUGH AS WELL AS WITHIN 100 NM EAST OF THE AXIS. A BROAD UPPER RIDGE COVERS THE REMAINDER OF THE EASTERN TROPICAL ATLC PROVIDING MOSTLY FAIR CONDITIONS ACROSS THE AREA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS