811 
 WTNT44 KNHC 272058
 TCDAT4
  
 TROPICAL STORM ISAAC DISCUSSION NUMBER  27
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092012
 400 PM CDT MON AUG 27 2012
  
 THE MUCH ANTICIPATED INTENSIFICATION PROCESS APPEARS TO HAVE FINALLY
 STARTED BASED ON REPORTS FROM AN AIR FORCE RESERVE RECONNAISSANCE
 AIRCRAFT AND FROM NEARBY NOAA BUOY 42003. THE CENTRAL PRESSURE HAS
 DECREASED BY AT LEAST 7 MB SINCE THE PREVIOUS ADVISORY. THE HIGHEST
 FLIGHT-LEVEL WINDS OBSERVED HAVE BEEN 74 KT IN THE SOUTHWEST
 QUADRANT AND THE HIGHEST BIAS-ADJUSTED SFMR WINDS ARE NEAR 58 KT.
 THESE DATA SUPPORT AN INTENSITY OF 60 KT.
  
 ISAAC WOBBLED WESTWARD THIS AFTERNOON...BUT A REPRESENTATIVE INITIAL
 MOTION ESTIMATE IS 305/10. THE LATEST 12Z NHC MODEL GUIDANCE IS IN
 BETTER AGREEMENT ON A WEST-NORTHWEST TO NORTHWEST MOTION TOWARD THE
 SOUTHEAST LOUISIANA AND MISSISSIPPI COASTAL AREAS OVER THE NEXT
 36-48 HOURS. AFTER 48 HOURS...HOWEVER...THE MODEL GUIDANCE REMAINS
 DIVERGENT ON THE HANDLING OF A SHORTWAVE TROUGH FORECAST TO DIG
 SOUTHEASTWARD FROM THE UPPER MIDWEST AND INTO THE MID-ATLANTIC
 REGION...FOLLOWED BY A RIDGE BUILDING IN BEHIND THE TROUGH. THE GFS
 AND ECMWF...OUR MOST RELIABLE MODELS... NOW HAVE VERY SIMILAR
 SOLUTIONS THROUGH DAY 5...AND THE OFFICIAL FORECAST TRACK IS
 BETWEEN THOSE TWO MODELS.
  
 SATELLITE DATA INDICATE ISAAC HAS BECOME BETTER ORGANIZED OVER THE
 PAST 6 HOURS WITH THE DEVELOPMENT OF A CENTRAL DENSE OVERCAST CLOUD
 PATTERN OVER THE CENTER ALONG WITH A DEVELOPING EYE IN RECON DATA.
 SATELLITE DATA T-NUMBERS HAVE INCREASED TO T4.5/77 KT FROM TAFB AND
 SAB. RECON WIND DATA INDICATE THE RADIUS OF MAXIMUM WINDS HAS ALSO
 PULLED INWARD TO ABOUT 30 N MI. ALTHOUGH ADDITIONAL CONVECTION HAS
 BEEN DEVELOPING IN THE NORTHEASTERN QUADRANT...DRY MID-LEVEL AIR
 STILL LURKS JUST TO THE EAST AND SOUTHEAST OF THE CDO FEATURE...
 WHICH COULD BE ENTRAINED INTO THE INNER CORE AT ANY TIME AND
 DISRUPT THE DEVELOPMENT PROCESS. DUE TO THE PROXIMITY OF DRY
 AIR...THE INTENSITY FORECAST INDICATES ONLY MODEST DEVELOPMENT FOR
 THE NEXT 24 HOURS. HOWEVER...STRENGTHENING IS EXPECTED TO CONTINUE 
 RIGHT UP UNTIL LANDFALL OCCURS DUE TO THE VERY WARM WATERS THE
 CYCLONE WILL BE PASSING OVER AND THE VERY FAVORABLE UPPER-LEVEL
 OUTFLOW REGIME THAT ISAAC IS FORECAST TO DEVELOP BY 24 HOURS. THE
 INTENSITY FORECAST IS JUST SLIGHTLY HIGHER THAN THE MODEL GUIDANCE.
  
 BECAUSE SIGNIFICANT HAZARDS EXTEND WELL AWAY FROM THE CENTER...IT IS
 IMPORTANT NOT TO FOCUS ON THE EXACT FORECAST TRACK. THE SLOW FORWARD
 SPED OF AROUND 5 KT AFTER LANDFALL WILL RESULT IN A HEAVY RAIN AND
 FLOOD SITUATION FOR PORTIONS OF THE CENTRAL GULF COAST AND LOWER
 MISSISSIPPI VALLEY REGIONS.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  27/2100Z 26.4N  86.2W   60 KT  70 MPH
  12H  28/0600Z 27.4N  87.5W   70 KT  80 MPH
  24H  28/1800Z 28.6N  89.0W   80 KT  90 MPH
  36H  29/0600Z 29.5N  90.0W   85 KT 100 MPH...NEAR THE COAST
  48H  29/1800Z 30.3N  90.7W   75 KT  85 MPH...INLAND
  72H  30/1800Z 32.2N  91.8W   35 KT  40 MPH...INLAND
  96H  31/1800Z 35.9N  92.1W   25 KT  30 MPH...INLAND
 120H  01/1800Z 38.7N  89.3W   20 KT  25 MPH...INLAND
  
 $$
 FORECASTER STEWART