000 AXNT20 KNHC 281744 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON SEP 28 2015 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1730 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION ELEVEN IS CENTERED NEAR 27.8N 69.6W AT 28/1500...MOVING WNW AT 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SCATTERED MODERATE CONVECTION IS 20N-29N BETWEEN . PLEASE SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLANTIC NEAR 11N15W TO 11N26W TO A 1012 MB SURFACE LOW CENTERED NEAR 11N38W. SCATTERED MODERATE CONVECTION IS FROM 08N-15N BETWEEN 20W-38W WHILE SCATTERED MODERATE TO STRONG CONVECTION PREVAILS E OF 19W. ...DISCUSSION... GULF OF MEXICO... AN UPPER-LEVEL LOW CENTERED ALONG THE COAST OF TEXAS NEAR 29N94W COVERING THE NW GULF MAINLY N OF 22N AND W OF 90W. AT THE SURFACE...A 1007 MB LOW IS CENTERED NEAR 28N94W EXTENDING A SURFACE TROUGH FROM 30N94W TO THE LOW CENTER TO 26N93W. SCATTERED MODERATE CONVECTION IS OBSERVED N OF THE LOW BETWEEN 91W-95W. A DIFFLUENT FLOW PREVAILS ACROSS THE EASTERN HALF OF THE BASIN SUPPORTING CLUSTERS OF MODERATE TO STRONG CONVECTION E OF 87W. ANOTHER 1007 MB LOW IS CENTERED ACROSS THE SE GULF NEAR 25N87W. A SURFACE TROUGH ACCOMPANIES THIS LOW EXTENDING FROM 26N86W TO 23N88W. SCATTEROMETER DATA DEPICTS GENTLE TO MODERATE FLOW ACROSS THE BASIN. EXPECT OVER THE NEXT 24 HOURS FOR THE SURFACE LOW ACROSS THE NW GULF TO DRIFT E ACROSS THE AREA WITH CONVECTION. THE SURFACE LOW CURRENTLY ACROSS THE SE GULF WILL MOVE NE WITH CONVECTION ALSO. ALTHOUGH UPPER-LEVEL WINDS ARE NOT FAVORABLE FOR TROPICAL DEVELOPMENT...THIS SYSTEM COULD PRODUCE LOCALLY HEAVY RAINFALL OVER PORTIONS OF THE NE GULF COAST... FLORIDA..AND THE SE CONUS DURING THE NEXT FEW DAYS. CARIBBEAN SEA... AN UPPER-LEVEL RIDGE COVERS THE W CARIBBEAN W OF 82W AND EXTENDS A RIDGE AXIS FROM THE GULF OF HONDURAS ACROSS W CUBA NEAR 22N84W INTO THE STRAITS OF FLORIDA AND THEN THE W ATLANTIC. WITH THIS...A DIFFLUENT FLOW PREVAILS ACROSS THE W CARIBBEAN SUPPORTING SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS AFFECTING THE W CARIBBEAN AND PORTIONS OF CUBA MAINLY W OF 83W. AN UPPER-LEVEL LOW IS CENTERED E OF THE LEEWARD ISLANDS. THIS LOW IS SUPPORTING ISOLATED CONVECTION ACROSS THE EASTERN CARIBBEAN AFFECTING THE LESSER ANTILLES AND PUERTO RICO...AS DEPICTED IN DOPPLER RADAR IMAGERY. SCATTEROMETER DATA DEPICTS GENTLE TO MODERATE TRADES ACROSS MOST OF THE CARIBBEAN...WITH MODERATE TO FRESH WINDS S OF 14N BETWEEN 70W-78W. OVER THE NEXT 24 HOURS...CONVECTION WILL CONTINUE ACROSS THE NW CARIBBEAN. FRESH TO STRONG TRADE WINDS WILL BE PULSING EACH NIGHT OFF COLOMBIA AND W VENEZUELA. ...HISPANIOLA... CLOUDY SKIES PREVAIL ACROSS THE ISLAND AS T.D. ELEVEN CONTINUES N OF THE AREA. LIMITED MOISTURE COMBINED WITH DAYTIME HEATING COULD GENERATE AFTERNOON ISOLATED SHOWERS/THUNDERSTORMS ACROSS THE INLAND PORTIONS OF THE ISLAND AND POSSIBLY ALONG THE ATLANTIC TODAY AND OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... THE UPPER-LEVEL RIDGE AXIS EXTENDS FROM THE NW CARIBBEAN ACROSS W CUBA AND THE STRAITS OF FLORIDA INTO THE W ATLANTIC COVERING THE AREA OF 67W. TROPICAL DEPRESSION ELEVEN IS JUST TO THE E OF THIS UPPER-LEVEL RIDGE. SEE THE SECTION ABOVE FOR MORE DETAILS. AN UPPER-LEVEL TROUGH PREVAILS OVER THE CENTRAL ATLANTIC N OF 27N BETWEEN 34W-60W SUPPORTING A FRONTAL SYSTEM ANALYZED AS A STATIONARY FRONT FROM 31N65W TO 27N47W AND AS A COLD FRONT FROM THAT POINT TO 31N32W. SCATTERED MODERATE CONVECTION IS OBSERVED ALONG AND N OF THE FRONT BETWEEN 56W-67W AND BETWEEN 31W-48W. A 1012 MB LOW...REMNANTS OF IDA...IS NEAR 24N51W WITH SURFACE TROUGH EXTENDING FROM 26N50W TO 19N51W. ISOLATED MODERATE CONVECTION IS OBSERVED FROM 19N-25N BETWEEN 48W-52W. TO THE E...A SURFACE RIDGE PREVAILS ANCHORED BY A 1019 MB SURFACE HIGH CENTERED NEAR 30N27W. OVER THE NEXT 24 HOURS...TROPICAL DEPRESSION ELEVEN WILL STRENGTHEN TO A TROPICAL STORM BY TONIGHT AS IT MOVES NW. CONVECTION IS STILL EXPECTED ACROSS THE CENTRAL ATLANTIC WITH THE FRONTAL BOUNDARIES. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ ERA