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Hurricane ISAAC


ZCZC MIATCPAT4 ALL
TTAA00 KNHC DDHHMM
 
BULLETIN
HURRICANE ISAAC INTERMEDIATE ADVISORY NUMBER  31A
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092012
600 PM CDT TUE AUG 28 2012
 
...CENTER OF ISAAC NEARING THE COAST OF SOUTHEAST LOUISIANA...STORM
SURGE FLOODING ALREADY OCCURRING...
 
 
SUMMARY OF 600 PM CDT...2300 UTC...INFORMATION
----------------------------------------------
LOCATION...28.9N 89.2W
ABOUT 15 MI...25 KM SSW OF THE MOUTH OF THE MISSISSIPPI RIVER
ABOUT 95 MI...150 KM SE OF NEW ORLEANS LOUISIANA
MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H
PRESENT MOVEMENT...NW OR 315 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...970 MB...28.64 INCHES
 
 
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...
 
NONE.
 
SUMMARY OF WATCHES AND WARNINGS IN EFFECT...
 
A HURRICANE WARNING IS IN EFFECT FOR...
* EAST OF MORGAN CITY LOUISIANA TO THE MISSISSIPPI-ALABAMA BORDER...
INCLUDING METROPOLITAN NEW ORLEANS...LAKE PONTCHARTRAIN...AND LAKE
MAUREPAS
 
A HURRICANE WATCH IS IN EFFECT FOR...
* INTRACOASTAL CITY TO MORGAN CITY LOUISIANA
 
A TROPICAL STORM WARNING IS IN EFFECT FOR...
* THE MISSISSIPPI-ALABAMA BORDER TO DESTIN FLORIDA
* MORGAN CITY TO CAMERON LOUISIANA
 
A TROPICAL STORM WATCH IS IN EFFECT FOR...
* EAST OF HIGH ISLAND TEXAS TO JUST WEST OF CAMERON LOUISIANA
 
FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE
INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED BY
YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST OFFICE. 
 
 
DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 600 PM CDT...2300 UTC...THE CENTER OF HURRICANE ISAAC WAS LOCATED
BY NOAA DOPPLER RADARS NEAR LATITUDE 28.9 NORTH...LONGITUDE 89.2
WEST. ISAAC IS MOVING TOWARD THE NORTHWEST NEAR 8 MPH...13 KM/H. A
NORTHWESTWARD MOTION AT A SLIGHTLY SLOWER SPEED IS EXPECTED OVER
THE NEXT DAY OR TWO. ON THE FORECAST TRACK...THE CENTER OF
HURRICANE ISAAC SHOULD REACH THE COASTLINE OF SOUTHEASTERN
LOUISIANA DURING THE NEXT FEW HOURS...AND CONTINUE MOVING 
FARTHER INLAND OVER SOUTHEASTERN LOUISIANA DURING THE NEXT 
DAY OR SO.

MAXIMUM SUSTAINED WINDS ARE NEAR 80 MPH...130 KM/H...WITH HIGHER
GUSTS. ISAAC IS A CATEGORY ONE HURRICANE ON THE SAFFIR-SIMPSON
HURRICANE WIND SCALE. SOME SLIGHT STRENGTHENING IS POSSIBLE
BEFORE ISAAC MAKES LANDFALL. GRADUAL WEAKENING IS EXPECTED AFTER
LANDFALL OCCURS.
 
HURRICANE-FORCE WINDS EXTEND OUTWARD UP TO 60 MILES...95 KM...
MAINLY TO THE NORTHEAST AND EAST OF THE CENTER. TROPICAL-STORM-FORCE
WINDS EXTEND OUTWARD UP TO 185 MILES...295 KM. TROPICAL STORM
CONDITIONS ARE OCCURRING ALONG THE COASTAL AREAS OF SOUTHEASTERN
LOUISIANA...MISSISSIPPI...AND ALABAMA. A SUSTAINED WIND OF 45 MPH
WITH A GUST TO 58 MPH WAS OBSERVED WITHIN THE PAST HOUR AT
LAKEFRONT AIRPORT IN NEW ORLEANS. 
 
THE MINIMUM CENTRAL PRESSURE REPORTED BY RECONNAISSANCE AIRCRAFT WAS
970 MB...28.64 INCHES.
 
 
HAZARDS AFFECTING LAND
----------------------
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...6 TO 12 FT
* ALABAMA...4 TO 8 FT
* SOUTH-CENTRAL LOUISIANA...3 TO 6 FT
* FLORIDA PANHANDLE...3 TO 6 FT
* APALACHEE BAY...2 TO 4 FT
* REMAINDER OF FLORIDA WEST COAST...1 TO 3 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.

A STORM SURGE OF 8.0 FEET WAS RECENTLY REPORTED AT A NATIONAL
OCEAN SERVICE TIDE GAUGE AT SHELL BEACH LOUISIANA.  A STORM SURGE
OF 5.3 FEET WAS OBSERVED AT A NATIONAL OCEAN SERVICE TIDE GAUGE IN
WAVELAND MISSISSIPPI. A STORM SURGE OF 3.1 FEET WAS ALSO REPORTED IN
PENSACOLA FLORIDA. 
 
WIND...TROPICAL STORM CONDITIONS WILL CONTINUE TO SPREAD ACROSS THE
WARNING AREA THIS EVENING...AND HURRICANE CONDITIONS SHOULD SPREAD
ONSHORE ACROSS SOUTHEASTERN LOUISIANA DURING THE NEXT FEW HOURS.
 
WINDS AFFECTING THE UPPER FLOORS OF HIGH-RISE BUILDINGS WILL BE
SIGNIFICANTLY STRONGER THAN THOSE NEAR GROUND LEVEL. AT ABOUT THE
30TH STORY...WINDS WOULD LIKELY BE ONE SAFFIR-SIMPSON CATEGORY
STRONGER THAN AT THE SURFACE.  A WIND GUST TO 106 MPH WAS RECENTLY
REPORTED OFF THE SOUTHEAST LOUISIANA COAST AT OIL RIG AT AN
ELEVATION OF 279 FEET...THE EQUIVANENT OF THE 28TH FLOOR. 
 
RAINFALL...ISAAC IS EXPECTED TO PRODUCE TOTAL RAINFALL AMOUNTS OF
7 TO 14 INCHES...WITH POSSIBLE ISOLATED MAXIMUM AMOUNTS OF 20
INCHES...OVER MUCH OF LOUISIANA...SOUTHERN MISSISSIPPI...SOUTHERN
ALABAMA...AND THE EXTREME WESTERN FLORIDA PANHANDLE. THESE RAINS
COULD RESULT IN SIGNIFICANT LOWLAND FLOODING.
 
TORNADOES...TORNADOES ARE POSSIBLE ALONG THE NORTHERN GULF COAST
THROUGH TONIGHT.
 
SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL CONTINUE TO
AFFECT THE WEST COAST OF FLORIDA AND PORTIONS OF THE NORTHERN GULF
COAST FOR THE NEXT DAY OR SO.
 
 
NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...800 PM CDT.
NEXT COMPLETE ADVISORY...1000 PM CDT.
 
$$
FORECASTER BROWN
 
NNNN


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Page last modified: Monday, 31-Dec-2012 12:09:25 UTC