000
WTNT44 KNHC 300255
TCDAT4
 
TROPICAL STORM ISAAC DISCUSSION NUMBER  36
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092012
1000 PM CDT WED AUG 29 2012
 
NATIONAL WEATHER SERVICE DOPPLER RADAR IMAGERY SHOWS THAT ISAAC
CONTINUES TO MOVE SLOWLY NORTHWESTWARD AT ABOUT 5 KT OVER
SOUTHEASTERN LOUISIANA.  THE SLOW FORWARD SPEED IS EXPECTED TO
PERSIST OVERNIGHT.  HOWEVER...A SLIGHT INCREASE IS FORWARD SPEED
AND A TURN TOWARD THE NORTH-NORTHWEST SHOULD OCCUR ON THURSDAY 
AS ISAAC MOVES AROUND THE WESTERN PERIPHERY OF A RIDGE THAT MOVES
EASTWARD INTO THE MID-ATLANTIC REGION.  IN 2 TO 3 DAYS...THE
CYCLONE SHOULD TURN NORTHEASTWARD...THEN EASTWARD AS IT ENTERS AN
AREA OF WEAK MID-LATITUDE WESTERLY FLOW. THE OFFICIAL FORECAST IS
CLOSE TO THE PREVIOUS TRACK THROUGH 36 HOURS...BUT IS ADJUSTED
SLIGHTLY WEST AT 48 AND 72 HOURS TO BE CLOSER TO THE LATEST
GUIDANCE.
 
RECENT WIND OBSERVATIONS NEAR THE NORTHERN GULF COAST INDICATE
THAT THE MAXIMUM WINDS ARE ABOUT 50 KT. THESE WINDS ARE PRIMARILY
OCCURRING OVER WATER.  CONTINUED WEAKENING IS EXPECTED AND ISAAC
SHOULD BECOME A TROPICAL DEPRESSION BY THURSDAY EVENING.
 
HEAVY RAINFALL AND A SIGNIFICANT FLOOD THREAT ARE EXPECTED TO SPREAD
INLAND ACROSS PORTIONS OF THE CENTRAL UNITED STATES DURING THE NEXT
SEVERAL DAYS.  WATER LEVELS ALONG THE NORTHERN GULF COAST WILL
REMAIN ELEVATED THROUGH EARLY THURSDAY.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  30/0300Z 30.3N  91.2W   50 KT  60 MPH
 12H  30/1200Z 31.2N  92.0W   40 KT  45 MPH...INLAND
 24H  31/0000Z 32.8N  92.9W   30 KT  35 MPH...INLAND
 36H  31/1200Z 34.9N  93.6W   25 KT  30 MPH...INLAND
 48H  01/0000Z 37.3N  93.4W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  02/0000Z 39.5N  91.3W   15 KT  15 MPH...POST-TROP/REMNT LOW
 96H  03/0000Z 40.0N  87.0W   15 KT  15 MPH...POST-TROP/REMNT LOW
120H  04/0000Z 40.5N  83.0W   15 KT  15 MPH...POST-TROP/REMNT LOW
 
$$
FORECASTER BROWN