000 AXNT20 KNHC 270546 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT APR 27 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF GUINEA NEAR 9N13W TO 5N19W. THE ITCZ BEGINS NEAR 4N20W AND CONTINUES ALONG 3N30W 2N40W TO 1N45W. A CLUSTER OF NUMEROUS STRONG CONVECTION IS MOVING OFF THE COAST OF AFRICA FROM 3N-9N BETWEEN 9W-14W. ISOLATED SHOWERS ARE WITHIN 75 NM EITHER SIDE OF THE ITCZ AXIS. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER LEVEL RIDGING CONTINUES ACROSS THE GULF OF MEXICO SUPPORTING SURFACE RIDGING ACROSS THE AREA EXTENDING FROM A 1031 MB HIGH CENTERED NEAR 38N74W. E TO SE SURFACE WINDS OF 5-15 KT SPREAD ACROSS THE GULF AND AROUND THE RIDGE ALONG WITH MOSTLY CLEAR SKIES. A WEAK SURFACE TROUGH IS INLAND ALONG THE W YUCATAN PENINSULA EXTENDING FROM 20N90W TO 16N91W. SCATTERED SHOWERS ARE POSSIBLE IN THE BAY OF CAMPECHE S OF 21N BEING ENHANCED BY THE SURFACE TROUGH AND MOISTURE ADVECTION FROM THE E PACIFIC OCEAN. LITTLE CHANGE IS EXPECTED OVER THE NEXT 24 HOURS AS SURFACE RIDGING REMAINS THE DOMINANT FEATURE. A COLD FRONT IS EXPECTED TO ENTER THE NW GULF SUNDAY MORNING. CARIBBEAN SEA... BROAD UPPER RIDGING ACROSS THE GULF OF MEXICO EXTENDS TO THE WESTERN CARIBBEAN. MOISTURE ADVECTION FROM THE E PACIFIC OCEAN BY NEARLY WESTERLY FLOW IS ENHANCING RAINSHOWERS IN THE YUCATAN CHANNEL AND WITHIN 100 NM FROM THE SOUTHERN COASTLINE OF CUBA. AN UPPER LEVEL TROUGH COVERS THE REMAINDER OF THE CARIBBEAN. VERY DRY AIR IN THE MIDDLE LEVELS ASSOCIATED TO THIS TROUGH IS PROVIDING MOSTLY FAIR CONDITIONS AT THE SURFACE WITH ONLY A FEW PATCHES OF POSSIBLE ISOLATED SHOWERS WITHIN 100 NM S OF LA HISPANIOLA AS WELL AS WITHIN 100 NM NE OF THE HONDURAS COASTLINE. ISOLATED SHOWERS ARE ALSO IN THE FAR SE CORNER OF THE BASIN. A MUCH LARGER AREA OF SCATTERED SHOWERS IS EAST OF THE WINDWARD ISLANDS ASSOCIATED WITH MOIST SOUTHWESTERLY FLOW ALOFT AROUND THE UPPER TROUGH. THIS AREA OF MOIST CONDITIONS EAST OF THE ISLANDS MAY DRIFT WEST OVER THE WEEKEND POSSIBLY BRINGING HEAVY RAINFALL TO SOME OF THE SOUTHERN LESSER ANTILLES. TRADEWIND FLOW OF 10-15 KT DOMINATES THE CENTRAL AND EASTERN CARIBBEAN WHILE WINDS UP TO 25 KT SPREAD OVER THE WESTERN AND SOUTHERN REGIONS OF THE BASIN DUE TO A TIGHTER PRESSURE GRADIENT. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH EXTENDS OFF THE EASTERN SEABOARD ALONG 66W SUPPORTING A COLD FRONT N OF THE DISCUSSION AREA AND A PREFRONTAL SURFACE TROUGH ALONG 30N66W 28N68W. SCATTERED SHOWERS ARE WITHIN 190 NM E OF THE TROUGH N OF 27N. AN INVERTED SURFACE TROUGH IS TO THE SOUTH FROM 25N69W TO 20N69W. ISOLATED SHOWERS ARE POSSIBLE ALONG THIS SECOND SURFACE TROUGH. FARTHER EAST AN UPPER LEVEL LOW LOCATED NEAR 36N34W IS SUPPORTING A 1005 MB SURFACE LOW NEAR 34N32W WITH AN ASSOCIATED COLD FRONT THAT ENTERS THE DISCUSSION AREA ALONG 30N26W 24N32W TO 23N42W. SCATTERED SHOWERS ARE WITHIN 100 NM E OF THE COLD FRONT S OF 28N BETWEEN 27W AND 42W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR