000 AXNT20 KNHC 300604 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU AUG 30 2012 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. ...SPECIAL FEATURES... THE CENTER OF TROPICAL STORM ISAAC AT 30/0600 UTC IS NEAR 30.5N 91.3W. ISAAC HAS BEEN INLAND FOR AT LEAST THE LAST 24 HOURS OR SO. ISAAC MADE LANDFALL AROUND 28/2345 UTC IN SOUTHEASTERN LOUISIANA. THIS POSITION IS NEAR GALLIANO LOUISIANA. THIS IS ALSO ABOUT 20 MILES SOUTHEAST OF HOUMA LOUISIANA AND ABOUT 50 MILES SOUTH-SOUTHWEST OF NEW ORLEANS LOUISIANA. ISAAC HAS BEEN STATIONARY DURING THE PAST HOUR...BUT A GENERAL MOTION TOWARD THE NORTHWEST NEAR 5 KT IS EXPECTED TO RESUME LATER THIS MORNING. THE MINIMUM CENTRAL PRESSURE IS 981 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 70 KT WITH GUSTS TO 85 KT. PLEASE READ THE NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC AND THE PUBLIC ADVISORY...MIATCPAT4/ WTNT34 KNHC FOR MORE DETAILS. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 29N TO 30N BETWEEN 90W AND 91W...SCATTERED MODERATE TO ISOLATED STRONG ELSEWHERE FROM 27N IN THE GULF OF MEXICO TO NORTHERN MISSISSIPPI BETWEEN THE FLORIDA PANHANDLE AND ALABAMA NEAR 86W AND 93W IN WESTERN LOUISIANA. ALL RESIDENTS IN LOUISIANA AND MISSISSIPPI AND SURROUNDING STATES SHOULD CONTINUE TO MONITOR ALL BULLETINS THAT ARE ISSUED BY THE NATIONAL HURRICANE CENTER AND THE LOCAL NATIONAL WEATHER SERVICE OFFICES FOR UPDATES ABOUT TROPICAL STORM ISAAC. THE CENTER OF TROPICAL STORM KIRK AT 30/0300 UTC IS NEAR 24.3N 45.3W. KIRK IS MOVING WEST-NORTHWESTWARD 8 KNOTS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1002 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 50 KT WITH GUSTS TO 60 KT. PLEASE READ THE NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC AND THE PUBLIC ADVISORY...MIATCPAT1/ WTNT31 KNHC FOR MORE DETAILS. SCATTERED MODERATE TO STRONG CONVECTIVE PRECIPITATION IS FROM 26N TO 27N BETWEEN 47W AND 49W. COMPARATIVELY DRIER AIR IN SUBSIDENCE IN WATER VAPOR IMAGERY COVERS THE ATLANTIC OCEAN TO THE SOUTH OF 20N TO THE WEST OF 50W...AND TO THE NORTH OF 20N TO THE WEST OF 50W. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 20N35W 16N38W TO A 1008 MB LOW PRESSURE CENTER THAT IS ALONG THE WAVE NEAR 13.5N38W. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 12.5N TO 15.5N BETWEEN 40W AND 43W...SCATTERED STRONG FROM 10N TO 12N BETWEEN 42W AND 48W. THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... NO OTHER TROPICAL WAVES ARE INCLUDED IN THE 30/0000 UTC SURFACE MAP ANALYSIS. PLEASE REFER TO THE SPECIAL FEATURES SECTION FOR DETAILS ABOUT THE 20N35W 13.5N38W TROPICAL WAVE AND THE ACCOMPANYING 1008 MB LOW PRESSURE CENTER. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH IS INDISTINCT TO THE EAST OF THE 20N35W 13.5N38W TROPICAL WAVE. THE MONSOON TROUGH HAS BEEN DISRUPTED BY THE LARGE-SCALE WIND FLOW THAT IS MOVING AROUND THE WAVE AND LOW CENTER FEATURE. THE ITCZ AXIS IS ALONG 12N52W 14N56W TO 14N61W NEAR SAINT LUCIA. ISOLATED MODERATE RAINSHOWERS ARE ELSEWHERE FROM 10N TO 16N BETWEEN 50W AND 60W. ...DISCUSSION... THE GULF OF MEXICO... THE UPPER LEVEL ANTICYCLONIC OUTFLOW FROM ISAAC COVERS THE SOUTHEASTERN U.S.A. AND MUCH OF THE GULF OF MEXICO... EXCEPT FOR THE SOUTHWESTERN CORNER OF THE AREA. COMPARATIVELY DRIER AIR IN SUBSIDENCE SHOWS UP IN WATER VAPOR IMAGERY IN THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO. THE SURFACE PRESSURE PATTERN IN THE EASTERN GULF OF MEXICO IS MADE UP OF THE CLOSED ISOBARS THAT SURROUND ISAAC. THESE ISOBARS COVER THE AREA THAT IS TO THE NORTH OF 26N. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT4...FOR MORE DETAILS ABOUT HURRICANE ISAAC. FROM THE FLORIDA KEYS AND THE STRAITS OF FLORIDA... INTO THE CARIBBEAN SEA... A MIDDLE LEVEL TO UPPER LEVEL TROUGH IS ALONG 23N82W IN WESTERN CUBA...TO 16N8W...INTO NORTHWESTERN COLOMBIA. NUMEROUS STRONG CONVECTIVE PRECIPITATION IS FROM 7N TO 9N BETWEEN 74W AND 78W. ISOLATED MODERATE CONVECTIVE PRECIPITATION IS ELSEWHERE IN THE CARIBBEAN SEA TO THE WEST OF 79W. THE REST OF THE CARIBBEAN SEA... THE MONSOON TROUGH IS ALONG 8N75W IN COLOMBIA...THROUGH 9N80W IN PANAMA...BEYOND NORTHWESTERN COSTA RICA. NUMEROUS STRONG CONVECTIVE PRECIPITATION IS FROM 7N TO 9N BETWEEN 74W AND 78W. THE BASE OF THE MIDDLE LEVEL TO UPPER LEVEL TROUGH THAT PASSES OVER NORTHWESTERN CUBA IS IN THE GULF OF URABA. BROAD UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE CARIBBEAN SEA THAT IS TO THE EAST OF THE CUBA-TO-GULF OF URABA MIDDLE LEVEL TO UPPER LEVEL TROUGH. UPPER LEVEL NORTHEASTERLY WIND FLOW IS ON THE WESTERN SIDE OF THE TROUGH. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR MORE DETAILS ABOUT THE 20 TO 25 KNOT WINDS AND 8 TO 11 FOOT SEA HEIGHTS FROM 11N TO 18N BETWEEN 68 AND 80W. THE REST OF THE ATLANTIC OCEAN... BROAD MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN TO THE SOUTH OF 20N BETWEEN 20W AND 70W. MIDDLE LEVEL NORTHERLY WIND FLOW COVERS THE AREA TO THE NORTH OF 20N BETWEEN T.S. KIRK AND 60W. COMPARATIVELY DRIER AIR IN SUBSIDENCE COVERS THE AREA...EXCEPT FOR THE CONVECTIVE PRECIPITATION THAT ACCOMPANIES T.S. KIRK. BROAD SURFACE ANTICYCLONIC WIND FLOW MOVES AROUND A 1019 MB HIGH PRESSURE CENTER THAT IS NEAR 27N62W. PLEASE READ THE HIGH SEAS FORECASTS...MIAHSFAT2...FOR DETAILS ABOUT TROPICAL STORM KIRK. A SECOND FEATURE OF INTEREST IS A 1009 MB LOW PRESSURE CENTER THAT STARTS AS A POSSIBLE TROPICAL CYCLONE 12 HOURS FROM NOW NEAR 13N37W...AT 24 HOURS 1008 MB POSSIBLE TROPICAL CYCLONE NEAR 13N41W...AND AT 48 HOURS 1008 MB POSSIBLE TROPICAL CYCLONE NEAR 14N46W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT