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Tropical Storm ISAAC


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BULLETIN
TROPICAL STORM ISAAC ADVISORY NUMBER  38
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092012
1000 AM CDT THU AUG 30 2012
 
...ISAAC SLOWLY WEAKENING OVER CENTRAL LOUISIANA BUT STILL
PRODUCING HEAVY RAINS...SEVERE WEATHER...AND HIGH WATER LEVELS
ALONG THE NORTHERN GULF COAST...
 
 
SUMMARY OF 1000 AM CDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...31.7N 92.1W
ABOUT 50 MI...80 KM S OF MONROE LOUISIANA
ABOUT 165 MI...270 KM NW OF NEW ORLEANS LOUISIANA
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...NNW OR 330 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...987 MB...29.15 INCHES
 
 
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...
 
THE TROPICAL STORM WARNING HAS BEEN DISCONTINUED WEST OF MORGAN CITY
LOUISIANA.
 
SUMMARY OF WATCHES AND WARNINGS IN EFFECT...
 
A TROPICAL STORM WARNING IS IN EFFECT FOR...
* MORGAN CITY LOUISIANA TO THE MISSISSIPPI-ALABAMA BORDER...
INCLUDING LAKE PONTCHARTRAIN AND LAKE MAUREPAS
 
FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST
OFFICE.
 
 
DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1000 AM CDT...1500 UTC...THE CENTER OF TROPICAL STORM ISAAC WAS
LOCATED NEAR LATITUDE 31.7 NORTH...LONGITUDE 92.1 WEST. ISAAC IS
MOVING TOWARD THE NORTH-NORTHWEST NEAR 9 MPH...15 KM/H. A TURN
TOWARD THE NORTH IS EXPECTED BY FRIDAY. ON THE FORECAST TRACK...THE
CENTER OF ISAAC WILL CONTINUE TO MOVE OVER LOUISIANA TODAY...OVER
ARKANSAS ON FRIDAY...AND OVER SOUTHERN MISSOURI FRIDAY NIGHT.
 
MAXIMUM SUSTAINED WINDS HAVE DECREASED TO NEAR 40 MPH...65
KM/H...WITH HIGHER GUSTS. FURTHER WEAKENING IS FORECAST DURING THE
NEXT 48 HOURS AS THE STORM CONTINUES TO MOVE OVER LAND...AND ISAAC
IS EXPECTED TO BECOME A TROPICAL DEPRESSION BY TONIGHT.
 
TROPICAL-STORM-FORCE WINDS EXTEND OUTWARD UP TO 195 MILES...315
KM...MAINLY TO THE SOUTHEAST OF THE CENTER OVER WATER AND ALONG THE
COASTS OF MISSISSIPPI AND SOUTHEASTERN LOUISIANA.
 
THE ESTIMATED MINIMUM CENTRAL PRESSURE BASED ON NEARBY SURFACE
OBSERVATIONS 987 MB...29.15 INCHES.
 
 
HAZARDS AFFECTING LAND
----------------------
EVEN THOUGH ISAAC IS NO LONGER A HURRICANE...LIFE-THREATENING
HAZARDS FROM STORM SURGE...INLAND FLOODING...AND TORNADOES ARE STILL
OCCURRING.
 
STORM SURGE...THE COMBINATION OF A STORM SURGE AND THE TIDE WILL
CAUSE NORMALLY DRY AREAS NEAR THE COAST TO BE FLOODED BY RISING
WATERS. THE WATER COULD REACH THE FOLLOWING DEPTHS ABOVE GROUND IF
THE PEAK SURGE OCCURS AT THE TIME OF HIGH TIDE...
 
* MISSISSIPPI AND SOUTHEASTERN LOUISIANA...4 TO 8 FT
* ALABAMA...2 TO 4 FT
* SOUTH-CENTRAL LOUISIANA...1 TO 3 FT
* FLORIDA PANHANDLE...1 TO 2 FT
 
THE DEEPEST WATER WILL OCCUR ALONG THE IMMEDIATE COAST IN AREAS OF
ONSHORE WINDS.  SURGE-RELATED FLOODING DEPENDS ON THE RELATIVE
TIMING OF THE SURGE AND THE TIDAL CYCLE...AND CAN VARY GREATLY OVER
SHORT DISTANCES.  FOR INFORMATION SPECIFIC TO YOUR AREA...PLEASE
SEE PRODUCTS ISSUED BY YOUR LOCAL WEATHER SERVICE OFFICE.  NEAR THE
COAST...THE SURGE WILL BE ACCOMPANIED BY LARGE AND DANGEROUS WAVES.
 
BASED ON OBSERVATIONS FROM NATIONAL OCEAN SERVICE TIDE GAUGES...AT
NEW CANAL STATION LOUISIANA...A STORM SURGE OF NEAR 6 FEET IS STILL
OCCURRING ON THE SOUTHERN SHORE OF LAKE PONTCHARTRAIN...AND A STORM
SURGE VALUE OF NEAR 5 FEET IS OCCURRING AT WAVELAND MISSISSIPPI.
 
WIND...TROPICAL STORM CONDITIONS WILL CONTINUE ACROSS THE WARNING
AREA THROUGH THIS MORNING.
 
RAINFALL...ISAAC IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS
OF 7 TO 14 INCHES...WITH ISOLATED MAXIMUM AMOUNTS OF 25 INCHES
POSSIBLE...OVER NORTHERN AND EASTERN LOUISIANA....MUCH OF
MISSISSIPPI...SOUTHWESTERN ALABAMA...ARKANSAS AND INTO SOUTHERN
MISSOURI THROUGH FRIDAY. THESE RAINS COULD RESULT IN SIGNIFICANT
LOWLAND FLOODING. THE HEAVY RAIN POTENTIAL WILL BE SPREADING
EASTWARD THIS WEEKEND INTO PORTIONS OF THE MID-WEST AND OHIO VALLEY
REGIONS.
 
TORNADOES...TORNADOES ARE POSSIBLE ALONG THE CENTRAL GULF COAST
REGION AND PARTS OF THE LOWER MISSISSIPPI RIVER VALLEY THROUGH
TODAY.
 
SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL CONTINUE TO
AFFECT THE WEST COAST OF FLORIDA AND THE NORTHERN GULF COAST FOR THE
NEXT DAY OR SO.
 
 
NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...100 PM CDT.
NEXT COMPLETE ADVISORY...400 PM CDT.
 
$$
FORECASTER STEWART
 
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