Flash Flood Warning 51, NWS New Orleans, LA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
751 PM CDT TUE AUG 28 2012

.SOUNDING DISCUSSION...
NO PROBLEMS WITH THIS EVENINGS 00Z FLIGHT. USED A DE-REALER AND
ADDITIONAL HYDROGEN DUE TO STRONG NORTH-NORTHEASTERLY WINDS WITH THE
APPROACH OF HURRICANE ISAAC. A LIGHT SHOWER AND OVERCAST SKIES
WERE OBSERVED AT RELEASE. MEAN LOW LEVEL WINDS FROM THE SURFACE
THROUGH 5K FEET ARE FROM THE NORTHEAST AT 55KTS. FROM 5K TO 10K
FEET THE WINDS VEER SOME AND ARE FROM THE EAST-NORTHEAST AT
60KTS. NORTHEASTERLY WINDS REMAIN THROUGH NEARLY 46K FEET. STORM
MOTION IS TO THE WEST AT 41KTS. THE COLUMN IS TROPICALLY SATURATED
OR NEARLY SATURATED FROM JUST ABOVE THE SURFACE THROUGH 20K FEET
OR NEAR 470MB. THE PW VALUE WAS AT 2.79 INCHES.

&&

.PREV DISCUSSION... /ISSUED 627 PM CDT TUE AUG 28 2012/

SYNOPSIS...

ISAAC HAS STRENGTHENED INTO A CATEGORY ONE HURRICANE.  AS OF 4 PM CDT
HURRICANE ISAAC HAD MAXIMUM SUSTAINED WINDS OF 80 MPH AND A MINIMUM
CENTRAL PRESSURE OF 975 MB. SOME SLIGHT STRENGTHENING IS POSSIBLE
BEFORE ISAAC MAKES LANDFALL. ISAAC IS CURRENTLY MOVING NORTHWESTWARD
AT 8 MPH. ISAAC IS EXPECTED TO CONTINUE MOVING IN A SIMILAR
DIRECTION BUT SLOW ITS FORWARD SPEED SLIGHTLY OVER THE NEXT 48
HOURS. DUE TO THE SLOW MOVEMENT...HEAVY AMOUNTS OF RAIN AS WELL AS
A LONG DURATION OF TROPICAL STORM FORCE WINDS ARE EXPECTED TO LAST
FOR 36 TO 48 HOURS. WIDESPREAD POWER OUTAGES WITH DOWNED TREES AND
POWER LINES LIKELY TO OCCUR DUE TO STRONG WINDS AND VERY WET SOIL.
ISAAC IS CURRENTLY LOCATED ABOUT 30 MILES SOUTH OF THE MOUTH OF
THE MISSISSIPPI.

SHORT TERM...

HURRICANE ISAAC IS EXPECTED TO MAKE LANDFALL LATE TONIGHT INTO
EARLY TOMORROW MORNING AS A CATEGORY ONE STORM NEAR THE MOUTH OF
THE MISSISSIPPI RIVER. A FLASH FLOOD WATCH CONTINUES UNTIL
THURSDAY MORNING AT 7AM AS ISAAC IS EXPECTED TO TRACK VERY SLOWLY
ACROSS SOUTHEASTERN AND EVENTUALLY INTO CENTRAL LOUISIANA THROUGH
TOMORROW NIGHT. ISOLATED SHORT LASTING QUICK SPIN UP WEAK
TORNADOES POSSIBLE ESPECIALLY ON THE RIGHT FRONT QUADRANT OF THE
STORM AS FRICTION IS CREATED UPON LANDFALL. THEREFORE A TORNADO
WATCH REMAINS IN AFFECT FOR PARTS OF SOUTHEASTERN LOUISIANA AND
PORTIONS OF SOUTHERN LOUISIANA. FOR THE LATEST INFORMATION FOR
TROPICAL STORM ISAAC PLEASE SEE THE LATEST HURRICANE LOCAL
STATEMENTS AND NATIONAL HURRICANE CENTER FORECASTS.

LONG TERM...

A DRYING TREND IS EXPECTED TO TAKE HOLD BEGINNING THURSDAY NIGHT
THROUGH THE WEEKEND AS A LARGE UPPER LEVEL RIDGE BUILDS IN OVER
THE EAST- CENTRAL PART OF THE COUNTRY. ABOVE NORMAL TEMPERATURES
WITH BELOW NORMAL POPS EXPECTED FROM THE WEEKEND INTO EARLY NEXT
WEEK.

AVIATION...

HAZARDOUS WEATHER CONDITIONS EXPECTED TO CONTINUE THROUGH THE
FORECAST PERIOD.

MARINE...

TROPICAL STORM CONDITIONS WILL CONTINUE OVERNIGHT WITH HURRICANE
CONDITIONS LIKELY AS WELL AS ISAAC CONTINUES TO TRACK NORTHWESTWARD
TOWARDS THE LOUISIANA COAST. EXPECT TROPICAL STORM TO HURRICANE
CONDITIONS TO LAST THROUGH TOMORROW EVENING. FOR MORE INFORMATION SEE
COASTAL WATERS FORECAST AND HURRICANE LOCAL STATEMENT.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  76  82  75  86 / 100 100 100  80
BTR  77  83  76  88 / 100 100  90  70
ASD  80  83  78  88 / 100 100  90  80
MSY  80  84  78  88 / 100 100  90  70
GPT  80  83  78  86 / 100 100  90  70
PQL  80  83  76  86 / 100 100  90  70

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH UNTIL 7 AM THURSDAY FOR THE FOLLOWING ZONES:
     ASCENSION...ASSUMPTION...EAST BATON ROUGE...EAST
     FELICIANA...IBERVILLE...LIVINGSTON...LOWER
     JEFFERSON...LOWER LAFOURCHE...LOWER PLAQUEMINES...LOWER ST.
     BERNARD...LOWER TERREBONNE...NORTHERN
     TANGIPAHOA...ORLEANS...POINTE COUPEE...SOUTHERN
     TANGIPAHOA...ST. CHARLES...ST. HELENA...ST. JAMES...ST.
     JOHN THE BAPTIST...ST. TAMMANY...UPPER JEFFERSON...UPPER
     LAFOURCHE...UPPER PLAQUEMINES...UPPER ST. BERNARD...UPPER
     TERREBONNE...WASHINGTON...WEST BATON ROUGE...AND WEST
     FELICIANA.

     HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES:
     ASCENSION...ASSUMPTION...LIVINGSTON...LOWER
     JEFFERSON...LOWER LAFOURCHE...LOWER PLAQUEMINES...LOWER ST.
     BERNARD...LOWER TERREBONNE...NORTHERN
     TANGIPAHOA...ORLEANS...SOUTHERN TANGIPAHOA...ST.
     CHARLES...ST. JAMES...ST. JOHN THE BAPTIST...ST.
     TAMMANY...UPPER JEFFERSON...UPPER LAFOURCHE...UPPER
     PLAQUEMINES...UPPER ST. BERNARD...UPPER TERREBONNE...AND
     WASHINGTON.

     TROPICAL STORM WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING
     ZONES: EAST BATON ROUGE...EAST
     FELICIANA...IBERVILLE...POINTE COUPEE...ST. HELENA...WEST
     BATON ROUGE...AND WEST FELICIANA.

GM...HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES:
     BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM
     BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI
     RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO
     STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM
     PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS
     FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60
     NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA
     RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO
     THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60
     NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE
     MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60
     NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE
     MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE
     BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND
     MISSISSIPPI SOUND.

MS...FLASH FLOOD WATCH UNTIL 7 AM THURSDAY FOR THE FOLLOWING ZONES:
     AMITE...HANCOCK...HARRISON...JACKSON...PEARL
     RIVER...PIKE...WALTHALL...AND WILKINSON.

     TROPICAL STORM WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING
     ZONES: AMITE...PIKE...WALTHALL...AND WILKINSON.

     HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES:
     HANCOCK...HARRISON...JACKSON...AND PEARL RIVER.

GM...HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES:
     BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM
     BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI
     RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO
     STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM
     PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS
     FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60
     NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA
     RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO
     THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60
     NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE
     MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60
     NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE
     MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE
     BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND
     MISSISSIPPI SOUND.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NEW ORLEANS LA
705 PM CDT TUE AUG 28 2012

GMZ530-532-534-536-538-550-552-555-557-570-572-575-577-LAZ034>037-
039-040-046>050-056>072-MSZ068>071-077-080>082-300015-
LAKE PONTCHARTRAIN AND LAKE MAUREPAS-MISSISSIPPI SOUND-
LAKE BORGNE-CHANDELEUR SOUND-BRETON SOUND-
COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT
20 NM-
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER
TO PORT FOURCHON OUT 20 NM-
COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER OUT 20 NM-
COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM-
COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM
20 TO 60 NM-
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER
TO PORT FOURCHON FROM 20 TO 60 NM-
COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER FROM 20 TO 60 NM-
COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO
60 NM-POINTE COUPEE-WEST FELICIANA-EAST FELICIANA-ST. HELENA-
WASHINGTON-ST. TAMMANY-IBERVILLE-WEST BATON ROUGE-
EAST BATON ROUGE-ASCENSION-LIVINGSTON-ASSUMPTION-ST. JAMES-
ST. JOHN THE BAPTIST-UPPER LAFOURCHE-ST. CHARLES-UPPER JEFFERSON-
ORLEANS-UPPER PLAQUEMINES-UPPER ST. BERNARD-UPPER TERREBONNE-
LOWER TERREBONNE-LOWER LAFOURCHE-LOWER JEFFERSON-
LOWER PLAQUEMINES-LOWER ST. BERNARD-NORTHERN TANGIPAHOA-
SOUTHERN TANGIPAHOA-WILKINSON-AMITE-PIKE-WALTHALL-PEARL RIVER-
HANCOCK-HARRISON-JACKSON-
705 PM CDT TUE AUG 28 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST
LOUISIANA...SOUTH MISSISSIPPI AND THE ADJACENT COASTAL WATERS.

.DAY ONE...TONIGHT

WINDS IN ADVANCE OF HURRICANE ISAAC WILL REACH TROPICAL
STORM FORCE ACROSS MOST AREAS IN OUR CWA BY LATE TONIGHT.
CONDITIONS WILL CONTINUE TO DETERIORATE RAPIDLY FROM SOUTH TO
NORTH ACROSS SOUTHEASTERN LOUISIANA AND SOUTHERN MISSISSIPPI
OVERNIGHT. STAY TUNED TO THE LATEST FORECAST UPDATES AND HURRICANE
LOCAL STATEMENTS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY
THE LATEST FORECAST FROM THE NATIONAL HURRICANE CENTER CALLS FOR
ISAAC TO MAKE LANDFALL AS A CATEGORY ONE HURRICANE NEAR THE MOUTH OF
THE MISSISSIPPI RIVER LATE TONIGHT INTO EARLY WEDNESDAY MORNING.

A HURRICANE WARNING REMAINS IN EFFECT FOR COASTAL MISSISSIPPI AND
MUCH OF SOUTHEAST LOUISIANA SOUTH AND EAST OF A MCCOMB TO BATON
ROUGE LINE. A TROPICAL STORM WARNING IS IN EFFECT FOR THE
REMAINDER OF SOUTHEAST LOUISIANA...ALONG AND NORTHWEST OF A
MCCOMB TO BATON ROUGE LINE. STAY TUNED TO THE LATEST FORECASTS
AND ADVISORIES ISSUED BY THE NATIONAL HURRICANE CENTER ON
HURRICANE ISAAC.

A FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH
THROUGH 7 AM THURSDAY. 10 TO 15 INCHES OF RAINFALL POSSIBLE WITH
LOCALLY UP TO 20 INCHES AS ISAAC SLOWLY DRAGS NORTHWESTWARD ACROSS
SOUTHERN LOUISIANA TUESDAY NIGHT THROUGH WEDNESDAY AFTERNOON.

A TORNADO WATCH IS NOW IN AFFECT UNTIL 7 AM CDT TOMORROW MORNING
FOR PORTIONS OF EXTREME SOUTHEASTERN LOUISIANA AND PARTS OF
EXTREME SOUTHERN MISSISSIPPI.

.SPOTTER INFORMATION STATEMENT...

THE ACTIVATION OF AMATEUR RADIO WEATHER NETWORKS WILL LIKELY BE
NEEDED THROUGH THURSDAY MORNING.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
210 AM CDT WED AUG 29 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0140 AM     HURRICANE        BELLE CHASSE            29.85N 90.00W
08/29/2012                   PLAQUEMINES        LA   AMATEUR RADIO

            BELLE CHASSE FERRY DOCK MEASURED 113 MPH WIND GUST.

&&

24/RR