Severe Thunderstorm Warning 148, NWS New Orleans, LA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
316 PM CDT WED JUN 8 2011

.SYNOPSIS...
SURFACE HIGH CENTERED OVER THE WESTERN ATLANTIC WITH THE RIDGE
AXIS EXTENDING WESTWARD THROUGH THE NORTHERN GULF COAST REGION.
A SURFACE LOW IS CENTERED NEAR THE GREAT LAKES WITH A COLD FRONT
EXTENDING SOUTHWESTWARD INTO NORTHERN TEXAS. A DRY LINE EXTENDS
FROM NORTH CENTRAL OKLAHOMA SOUTHWARD INTO SOUTHWEST TEXAS.

LOCALLY...SCATTERED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED
ACROSS THE AREA...A FEW OF THEM HAVE BEEN STRONG TO BORDERLINE
SEVERE. OUTSIDE OF CONVECTION...TEMPERATURES ARE HOVERING IN THE
LOWER 90S. IN OR NEAR CONVECTION...RAIN COOLED DOWN DRAFTS AND
OUT FLOW HAVE DROPPED TEMPERATURES AS LOW AS THE MID 70S IN SOME
AREAS. DEW POINTS STILL HOVERING IN THE MID 60S TO NEAR 70
DEGREES.

&&

.DISCUSSION...
ONLY MINOR TWEAKS MADE TO THE FORECAST PACKAGE AS MODEL GUIDANCE
REMAINS IN GOOD AGREEMENT AND FORECAST THINKING HAS NOT CHANGED IN
THE LAST 12 HOURS.

WHILE SCATTERED CONVECTION OVER THE LAST SEVERAL DAYS HAS BROUGHT
A WELCOME RESPITE FROM THE OPPRESSIVE HEAT...IT WON/T HANG AROUND
MUCH LONGER. SHOWER AND THUNDERSTORM COVERAGE WILL DIMINISH
OVER THE NEXT FEW DAYS AS THE BROAD UPPER LOW OVER THE GULF MOVES
AWAY FROM THE AREA AND AN UPPER RIDGE BUILDS BACK INTO THE AREA.
THIS WILL RESULT IN WEAKER LAPSE RATES AND THE SUBSIDENCE ALOFT
WILL RESULT IN A STRONGER MID LEVEL CAP THAT COUNTERACTS THE
RISING AIR NEEDED TO DEVELOP CLOUD COVER/THUNDERSTORMS. ISOLATED
SHOWERS AND THUNDERSTORMS WILL STILL REMAIN POSSIBLE MOST
AFTERNOONS THROUGH THE PERIOD.

THE LOWER COVERAGE OF CLOUDS AND THUNDERSTORMS WILL ALSO RESULT
IN HIGHER AFTERNOON TEMPERATURES. THANKFULLY WE ARE NOT EXPECTING
WIDESPREAD TRIPLE DIGITS...THOUGH HEAT INDEX VALUES WILL APPROACH
OR CROSS THE CENTURY MARK ACROSS MUCH OF THE AREA BY SATURDAY.

&&

.AVIATION...
MOSTLY VFR CONDITIONS ARE EXPECTED THROUGH THE DAY...OVERNIGHT AND
THURSDAY. SCATTERED SHRA/TSRA WITH TEMPO RESTRICTED VSBYS/CIGS
WILL OCCUR THIS AFTERNOON...STARTING FROM 18-22Z FOR
HSA...NEW...MSY AND HUM AND 19-23Z FOR MCB AND BTR. CONVECTION
WILL DEVELOP FROM PEARL RIVER COUNTY THE LAKES TO TERREBONNE BAY
AT 18Z AND SLOWLY DRIFT NORTHWEST THROUGH THE AFTERNOON.
CONVECTION THREAT SHOULD END BY 02Z AROUND TAF SITES...ENDING
AROUND MIDNIGHT ALONG THE COAST.

&&

.MARINE...
GENERALLY TRANQUIL CONDITIONS EXPECTED OVER THE COASTAL WATERS
THROUGH THE PERIOD. THE MAIN EXCEPTION WILL BE IN THE VICINITY OF
THUNDERSTORMS...WHERE WINDS AND SEAS CAN BE SIGNIFICANTLY HIGHER.
THUNDERSTORM ACTIVITY IS EXPECTED TO DIMINISH SIGNIFICANTLY OVER
THE NEXT FEW DAYS AS DEEP HIGH PRESSURE BUILDS OVER THE AREA.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  67  94  69  95 /  20  20  10  10
BTR  71  94  71  95 /  20  20  10  10
ASD  70  92  71  91 /  20  20  10  10
MSY  74  93  73  93 /  20  20  10  10
GPT  71  91  72  91 /  20  20  10  10
PQL  67  92  69  93 /  20  20  10  10

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&

AVIATION...18
REST OF DISCUSSION...95/DM

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1052 AM CDT WED JUN 8 2011

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>082-091200-
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-
1052 AM CDT WED JUN 8 2011

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

SCATTERED THUNDERSTORMS ARE ONCE AGAIN EXPECTED TO DEVELOP THIS
AFTERNOON. AREAS ALONG AND NORTH OF THE INTERSTATE 10/12 CORRIDOR
WILL SEE THE HIGHEST CHANCES OF THUNDERSTORM DEVELOPMENT. A FEW
THUNDERSTORMS WILL HAVE THE POTENTIAL TO PRODUCE HAIL AND STRONG
WIND GUSTS. THESE WINDS COULD DOWN SMALL TREE LIMBS AND BLOW
AROUND UNSECURED OBJECTS LIKE TRASH CANS AND LAWN FURNITURE.
LOCALIZED VERY HEAVY RAINFALL IS ALSO POSSIBLE.

AN OZONE ACTION DAY IS IN EFFECT FOR THE BATON ROUGE AREA THROUGH
MIDNIGHT TONIGHT.

FLOOD WARNINGS WILL REMAIN IN EFFECT FOR SEVERAL POINTS ALONG THE
MISSISSIPPI AND ATCHAFALAYA RIVERS. PLEASE REFER TO THE LATEST
FLOOD WARNINGS AND STATEMENTS FOR DETAILS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

ISOLATED THUNDERSTORMS WILL BE POSSIBLE ON THURSDAY. THESE
THUNDERSTORMS SHOULD REMAIN BELOW SEVERE LIMITS...BUT COULD
PRODUCE STRONG GUSTY WINDS AND FREQUENT LIGHTNING.

AN OZONE ACTION DAY WILL BE IN EFFECT FOR THE BATON ROUGE AREA ON
WEDNESDAY FROM 6 AM UNTIL MIDNIGHT CDT.

FLOOD WARNINGS WILL REMAIN IN EFFECT FOR SEVERAL POINTS ALONG THE
MISSISSIPPI AND ATCHAFALAYA RIVERS. PLEASE REFER TO THE LATEST
FLOOD WARNINGS AND STATEMENTS FOR DETAILS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED. HOWEVER...ANY REPORTS OF
SEVERE WEATHER THIS EVENING OR WEDNESDAY SHOULD BE RELAYED TO THE
NATIONAL WEATHER SERVICE.

LAZ056-082030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
227 PM CDT WED JUN 8 2011

...STRONG THUNDERSTORM MOVING NORTHWEST AFFECTING ASSUMPTION
PARISH...

AT 222 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
STRONG THUNDERSTORM ABOUT 2 MILES SOUTH OF NAPOLEONVILLE...MOVING
NORTHWEST AT 10 MPH.

THE STRONG THUNDERSTORM WILL AFFECT AREAS IN AND AROUND...
NAPOLEONVILLE...PAINCOURTVILLE AND PIERRE PART

THE PRIMARY THREATS FROM THIS STORM ARE PEA TO DIME SIZE HAIL AND
WIND GUSTS TO NEAR 40 MPH...WHICH COULD DOWN TREE LIMBS AND BLOW
AROUND UNSECURED SMALL OBJECTS. SEEK SHELTER IN A SAFE HOME OR
BUILDING UNTIL THIS STORM HAS PASSED.

THIS STORM COULD PRODUCE RAINFALL AMOUNTS OF ONE TO TWO INCHES IN A
SHORT PERIOD OF TIME...RESULTING IN PONDING OF WATER AROUND LOW LYING
ROADWAYS. REMEMBER...DO NOT DRIVE YOUR VEHICLE INTO WATER COVERED
ROADWAYS. THE DEPTH MAY BE TOO GREAT TO ALLOW A SAFE CROSSING.

LAZ040-082030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
232 PM CDT WED JUN 8 2011

...STRONG THUNDERSTORM MOVING NORTHWEST AFFECTING ST. TAMMANY
PARISH...

AT 227 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
STRONG THUNDERSTORM 7 MILES NORTHEAST OF COVINGTON...OR ABOUT 5 MILES
NORTH OF ABITA SPRINGS...MOVING NORTHWEST AT 15 MPH.

THE STRONG THUNDERSTORM WILL AFFECT AREAS IN AND AROUND...FOLSOM

THE PRIMARY THREATS FROM THIS STORM ARE PEA TO DIME SIZE HAIL AND
WIND GUSTS TO NEAR 40 MPH...WHICH COULD DOWN TREE LIMBS AND BLOW
AROUND UNSECURED SMALL OBJECTS. SEEK SHELTER IN A SAFE HOME OR
BUILDING UNTIL THIS STORM HAS PASSED.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
331 PM CDT WED JUN 08 2011

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

0310 PM     HAIL             3 E DONALDSONVILLE      30.10N 90.95W
06/08/2011  E0.50 INCH       ASCENSION          LA   PUBLIC

            REPORTED AT BEST WESTERN PLANTATION INN.

&&

JS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
337 PM CDT WED JUN 08 2011

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

0310 PM     HAIL             3 NNW CONVENT           30.06N 90.85W
06/08/2011  E0.75 INCH       ST. JAMES          LA   PUBLIC

&&

JS

LAZ050-082130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
359 PM CDT WED JUN 8 2011

...STRONG THUNDERSTORM MOVING WEST AFFECTING LIVINGSTON PARISH...

AT 355 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
STRONG THUNDERSTORM 7 MILES SOUTHEAST OF DENHAM SPRINGS...OR ABOUT 5
MILES SOUTH OF WALKER...MOVING NORTHWEST AT 15 MPH.

THE STRONG THUNDERSTORM WILL AFFECT AREAS IN AND AROUND...WALKER AND
DENHAM SPRINGS

THE PRIMARY THREATS FROM THIS STORM ARE PEA TO DIME SIZE HAIL AND
WIND GUSTS TO NEAR 40 MPH...WHICH COULD DOWN TREE LIMBS AND BLOW
AROUND UNSECURED SMALL OBJECTS. SEEK SHELTER IN A SAFE HOME OR
BUILDING UNTIL THIS STORM HAS PASSED.

LAZ037-050-082130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
406 PM CDT WED JUN 8 2011

...STRONG THUNDERSTORM MOVING NORTHWEST AFFECTING ST. HELENA
PARISH...LIVINGSTON PARISH...

AT 405 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
STRONG THUNDERSTORM 12 MILES SOUTHWEST OF AMITE...OR ABOUT 5 MILES
SOUTH OF MONTPELIER...MOVING NORTHWEST AT 15 MPH.

THE STRONG THUNDERSTORM WILL AFFECT AREAS IN AND AROUND...MONTPELIER

THE PRIMARY THREATS FROM THIS STORM ARE PEA TO DIME SIZE HAIL AND
WIND GUSTS TO NEAR 40 MPH...WHICH COULD DOWN TREE LIMBS AND BLOW
AROUND UNSECURED SMALL OBJECTS. SEEK SHELTER IN A SAFE HOME OR
BUILDING UNTIL THIS STORM HAS PASSED.