000 AXNT20 KNHC 272342 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN SEP 27 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 2315 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION IDA IS CENTERED NEAR 24.5N 48.7W AT 27/2100 UTC OR ABOUT 885 NM ENE OF THE NORTHERN LEEWARD ISLANDS MOVING W AT 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB. MAXIMUM SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 KT. ISOLATED MODERATE CONVECTION IS FROM 24N-29N BETWEEN 45W-50W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. A 1007 MB SURFACE LOW IS CENTERED NORTH OF THE YUCATAN PENINSULA COAST NEAR 22N88W THAT LIES BENEATH SOUTHWESTERLY FLOW AND A DIFFLUENT ENVIRONMENT ALOFT. WHILE SCATTERED MODERATE CONVECTION IS OCCURRING GENERALLY TO THE EAST AND NORTHEAST OF THE EXPOSED LOW-LEVEL CIRCULATION CENTER...UPPER LEVEL WIND SHEAR REMAINS A HINDRANCE TO ANY SIGNIFICANT CENTRALLY ORGANIZED CONVECTION IN CLOSE PROXIMITY TO THE SURFACE LOW. ASIDE FROM THE MEDIUM POTENTIAL TO BECOME A TROPICAL CYCLONE IN THE NEXT 48 HOURS... THE PRIMARY IMPACT FROM THIS SYSTEM WILL CONTINUE TO BE HEAVY RAINFALL ACROSS THE EASTERN GULF OF MEXICO AND FLORIDA PENINSULA THROUGH LATE MONDAY. MID-LEVEL ENERGY IS NOTED ON WATER VAPOR IMAGERY IN THE VICINITY OF 26N68W THAT SUPPORTS A 1009 MB SURFACE LOW CENTERED NEAR 27N69W. A SURFACE TROUGH AXIS EXTENDS S-SW TO 24N70W TO 22N74W WITH SCATTERED MODERATE CONVECTION OCCURRING GENERALLY WITHIN THE SOUTHEASTERN SEMICIRCLE OF THE LOW FROM 24N-28N BETWEEN 66W- 70W. ISOLATED MODERATE CONVECTION IS ELSEWHERE FROM 22N-28N BETWEEN 62W-70W. THE SYSTEM HOLDS A MEDIUM CHANCE FOR TROPICAL CYCLONE DEVELOPMENT DURING THE NEXT 48 HOURS AS IT MOVES NORTHWARD AT 5-10 KT. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 10N35W TO 16N39W MOVING W AT 5 KT. THE WAVE COINCIDES WITH SUBTLE 700 MB TROUGHING ALOFT BETWEEN 35W-42W AS WELL AS A LOW-LEVEL MONSOONAL GYRE FOCUSED ON A 1009 MB LOW CENTERED AT THE SOUTHERN EXTENT OF THE WAVE AXIS NEAR 10N35W. SCATTERED MODERATE CONVECTION IS FROM 09N-12N BETWEEN 35W-40W...WITH ISOLATED MODERATE CONVECTION ELSEWHERE FROM 04N- 14N BETWEEN 27W-40W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 14N17W TO 12N31W TO A 1009 MB LOW NEAR 10N35W TO 07N43W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N43W TO 02N51W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 08N-16N BETWEEN 11W-18W. ISOLATED MODERATE CONVECTION IS FROM 04N-14N BETWEEN 27W-40W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL LOW IS NOTED ON WATER VAPOR IMAGERY CENTERED OVER COASTAL TEXAS THIS EVENING NEAR 30N95W PROVIDING MUCH OF THE GULF WITH SOUTHWESTERLY DIFFLUENT FLOW ALOFT. THE ENERGY ALOFT SUPPORTS A 1008 MB SURFACE LOW CENTERED NEAR 28N94W GENERATING WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS N OF 27N BETWEEN 87W-95W. OVER THE EASTERN GULF...THE UPPER LEVEL DIFFLUENCE IS MAXIMIZED DUE TO A SHARP RIDGE AXIS ALONG 80W. THE DIFFLUENCE ALONG WITH A 1007 MB SURFACE LOW CENTERED OFF THE COAST OF THE NORTHERN YUCATAN PENINSULA NEAR 22N88W CONTINUES TO GENERATE SCATTERED TO NUMEROUS SHOWERS AND SCATTERED TSTMS ACROSS THE EASTERN GULF WATERS AND MUCH OF THE FLORIDA PENINSULA THIS EVENING. THIS LOW IS EXPECTED TO DRIFT NORTHWARD DURING THE NEXT 24-36 HOURS WITH PLENTY OF CONVECTIVE PRECIPITATION OCCURRING AS A RESULT ACROSS THE FAR EASTERN GULF WATERS AND FLORIDA PENINSULA THROUGH LATE MONDAY INTO EARLY TUESDAY. CARIBBEAN SEA... AN UPPER LEVEL RIDGE AXIS EXTENDS FROM OVER GUATEMALA NEAR 17N89W TO OVER CENTRAL CUBA AND BEYOND TO THE NORTH OVER THE SW NORTH ATLC WATERS. MIDDLE TO UPPER LEVEL DIFFLUENCE IS MAXIMIZED OVER THE NW CARIBBEAN AND PORTIONS OF CUBA GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING GENERALLY W OF 79W THIS EVENING. FARTHER SOUTH...ISOLATED SHOWERS AND TSTMS ARE OCCURRING ACROSS PORTIONS OF COSTA RICA AND PANAMA DUE TO THE CLOSE PROXIMITY OF THE MONSOON TROUGH AXIS ALONG 10N/11N. CONDITIONS ACROSS THE EASTERN CARIBBEAN REMAIN FAIRLY QUIET AND TRANQUIL THIS EVENING WITH ONLY ISOLATED SHOWERS OCCURRING ACROSS HISPANIOLA AND A WEAK SURFACE TROUGH ANALYZED FROM 16N62W SE TO 13N54W IN ASSOCIATION WITH A BROAD UPPER LEVEL LOW CENTERED NEAR 16N60W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 75 NM EITHER SIDE OF THE BOUNDARY. OTHERWISE...MAINLY FRESH TO OCCASIONAL STRONG TRADES PERSIST WITH THE STRONGEST WINDS NOTED ACROSS SOUTH-CENTRAL PORTIONS. BY MID-WEEK...THE TRADES ARE EXPECTED TO RELAX SOMEWHAT INTO MODERATE TO FRESH BREEZE LEVELS AS BROAD FRONTAL TROUGHING IS EXPECTED TO OCCUPY MUCH OF THE SW NORTH ATLC REGION TO THE NORTH. ...HISPANIOLA... CURRENTLY LINGERING LATE AFTERNOON AND EARLY EVENING ISOLATED SHOWERS CONTINUE TO GRADUALLY DIMINISH WITH MOSTLY FAIR SKIES EXPECTED FOR THE OVERNIGHT HOURS INTO EARLY MONDAY. NORTHERLY FLOW ALOFT PREVAILS OVER THE ISLAND PROVIDING MOSTLY STABLE CONDITIONS AT THIS TIME. ATLANTIC OCEAN... ASIDE FROM THE SPECIAL FEATURES LOW CENTERED NEAR 27N69W...THE REMAINDER OF THE SW NORTH ATLC IS UNDER THE INFLUENCE OF A RELATIVELY DIFFLUENT ENVIRONMENT ALOFT WITH ISOLATED SHOWERS AND TSTMS OCCURRING GENERALLY W OF 78W THIS EVENING. FARTHER EAST ACROSS THE CENTRAL ATLC IS TROPICAL DEPRESSION IDA...WITH A COLD FRONT ANALYZED TO THE NORTH FROM 32N40W TO 29N51 THAT BECOMES STATIONARY TO 30N61W TO BEYOND 32N65W TO THE COAST OF THE CAROLINAS. ISOLATED SHOWERS AND TSTMS ARE OCCURRING WITHIN 180 NM EAST OF THE COLD FRONT AND WITHIN 120 NM EITHER SIDE OF THE STATIONARY FRONT W OF 55W. OTHERWISE...THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1018 MB HIGH CENTERED NEAR 30N29W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN