000 AXNT20 KNHC 112335 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI SEP 11 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2330 UTC. ...SPECIAL FEATURES... THE REMNANTS OF HENRI ARE CENTERED NEAR 40.0N 58.5W AT 11/2100 UTC OR ABOUT 465 NMI SSW OF CAPE RACE NEWFOUNDLAND MOVING NNE AT 21 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 40 KT. SCATTERED MODERATE CONVECTION IS FROM 40N-44N BETWEEN 54W-57W. FOR MORE INFORMATION SEE LAST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE E ATLANTIC WITH AXIS EXTENDING FROM 16N22W TO 08N24W...MOVING W AT 15 KT. THE WAVE COINCIDES WITH LOW AMPLITUDE 700 MB TROUGHING S OF 13N AND E OF 23W. SSMI TPW IMAGERY INDICATES THE WAVE IS EMBEDDED IN A ENVIRONMENT OF MODERATE TO HIGH MOISTURE. NO SIGNIFICANT CONVECTION IS OBSERVED WITH THIS FEATURE AT THIS TIME. A TROPICAL WAVE IS ACROSS THE CENTRAL ATLANTIC WITH AXIS EXTENDING FROM 18N39W TO 10N41W...MOVING W AT 15 KT. THE WAVE COINCIDES WITH A BROAD 700 MB TROUGH BETWEEN 33W-50W. THIS WAVE IS ALSO EMBEDDED IN AN ENVIRONMENT OF MODERATE TO HIGH MOISTURE...WITH HIGHER CONCENTRATIONS S OF 16N. SCATTERED MODERATE CONVECTION IS FROM 08N-14N BETWEEN 39W-43W. A TROPICAL WAVE...INCLUDING THE REMNANTS OF GRACE... IS OVER THE E CARIBBEAN WITH AXIS EXTENDING FROM 20N64W TO 12N64W...MOVING W AT 15 TO 20 KT. THE WAVE COINCIDES WITH A 700 MB TROUGH BETWEEN 60W AND 65W...AND A 850 MB RELATIVE VORTICITY MAXIMUM NEAR 17N63W. SCATTERED TO NUMEROUS MODERATE CONVECTION PREVAILS E OF THE WAVE AXIS AFFECTION THE LESSER ANTILLES FROM 13N-23N BETWEEN 58W-64W. A TROPICAL WAVE EXTENDS ACROSS THE W CARIBBEAN WITH AXIS FROM 17N75W TO 08N77W...MOVING W AT 15 TO 20 KT. THE WAVE COINCIDES WITH SUBTLE 700 MB TROUGHING BETWEEN 70W AND 76W. SCATTERED MODERATE CONVECTION IS FROM 08N TO 16N BETWEEN 73W AND 84W. SOME OF THIS CONVECTION IS ALSO ASSOCIATED WITH THE EASTERN PACIFIC MONSOON TROUGH. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N15W TO 08N24W TO 10N40W. THE ITCZ BEGINS W OF A TROPICAL WAVE NEAR 10N43W AND CONTINUES TO 06N56W. OTHER THAN CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...SCATTERED MODERATE CONVECTION IS FROM 06N-14N BETWEEN 43W-54W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER-LEVEL TROUGH EXTENDS FROM THE CENTRAL AND EASTERN US TO THE N GULF COAST. SHORTWAVE ENERGY ALOFT MOVING AROUND THE BASE OF THIS TROUGH IS SUPPORTING CLUSTERS OF MODERATE TO STRONG CONVECTION OVER THE NORTHERN GULF N OF 25N. A 1016 MB SURFACE HIGH IS CENTERED NEAR 28N86W SUPPORTING MAINLY GENTLE TO MODERATE ANTICYCLONIC WINDS ACROSS THE BASIN...WITH THE EXCEPTION OF VARIABLE AND GUSTY WINDS IN THE VICINITY OF CONVECTION OVER THE N GULF. OVER THE NEXT 24 HOURS...EXPECT FOR THE UPPER-LEVEL TROUGH TO DIG S AND E SUPPORTING CONVECTION ACROSS THE NORTHERN GULF WATERS. CARIBBEAN SEA... TWO TROPICAL WAVES ARE MOVING ACROSS THE CARIBBEAN. PLEASE REFER TO THE TROPICAL WAVES SECTION FOR DETAILS. AN ELONGATED UPPER- LEVEL ANTICYCLONE IS CENTERED OVER THE YUCATAN PENINSULA AND EXTENDS E ACROSS THE W CARIBBEAN MAINLY W OF 76W. ANOTHER AREA OF UPPER-LEVEL DIFFLUENCE PREVAILS OVER CUBA AND THE NW CARIBBEAN SUPPORTING SCATTERED MODERATE CONVECTION ACROSS THE ISLAND AND ADJACENT WATERS. TO THE E...AN UPPER-LEVEL CYCLONE IS CENTERED NEAR 16N70W AND EXTENDS ACROSS THE REMAINDER OF THE BASIN. THESE FEATURES ARE GENERATING UPPER-LEVEL DIFFLUENCE THAT SUPPORTS SCATTERED MODERATE CONVECTION S OF 13N BETWEEN 73W-83W. GENTLE TO MODERATE TRADES COVER THE MAJORITY OF THE CARIBBEAN BASIN EXCEPT A SMALL AREA OF MODERATE TO FRESH ALONG THE NORTHERN PORTION OF THE WAVE CURRENTLY OVER THE EASTERN CARIBBEAN. OVER THE NEXT 24 HOURS...EXPECT FOR THE WAVES TO CONTINUE MOVING W SUPPORTING CONVECTION. CONVECTION IS EXPECTED TO PREVAIL ACROSS THE SOUTHERN CARIBBEAN DUE TO THE PROXIMITY OF THE MONSOON TROUGH. ...HISPANIOLA... ISOLATED CONVECTION IS OBSERVED ACROSS THE CENTRAL PORTION OF THE ISLAND. THIS ACTIVITY WILL DISSIPATE LATER THIS EVENING. A TROPICAL WAVE WILL APPROACH THE ISLAND SUPPORTING SCATTERED MODERATE CONVECTION OVER THE NEXT 24-48 HOURS. LOCALLY HEAVY RAINFALL IS POSSIBLE. ATLANTIC OCEAN... TWO TROPICAL WAVES ARE MOVING ACROSS THE TROPICAL ATLANTIC. PLEASE REFER TO THE SECTION ABOVE FOR DETAILS. A SURFACE RIDGE EXTENDS ACROSS THE WHOLE BASIN ANCHORED BY A 1020 MB HIGH CENTERED NEAR 28N28W. UPPER-LEVEL DIFFLUENCE IS SUPPORTING ISOLATED CONVECTION ACROSS THE ATLANTIC WATERS W OF 50W. A WEAKNESS IN THE RIDGE WAS ANALYZED AS A 1016 MB SURFACE LOW CENTERED NEAR 27N38W. THIS LOW HAS A SURFACE TROUGH THAT EXTENDS FROM 30N36W TO THE LOW CENTER TO 26N40W. ISOLATED CONVECTION IS OBSERVED FROM 27N-30N BETWEEN 37W-40W. THE REMNANTS OF HENRI ARE OVER THE WEST CENTRAL ATLANTIC. PLEASE REFER TO THE SPECIAL FEATURES SECTION FOR MORE DETAILS. SCATTEROMETER DATA DEPICTS A GENTLE TO MODERATE ANTICYCLONIC FLOW PREVAILING ACROSS THE BASIN. EXPECT A SIMILAR WEATHER PATTERN TO PREVAIL OVER THE NEXT 24 HOURS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ ERA