Alert archive / Louisiana / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 83, NWS New Orleans, LA

May 12, 2019Terrebonne Parish, Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at May 12, 2019, 5:42 AM CDT for Terrebonne Parish, Louisiana. It was in force for 33 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
May 12, 2019, 5:42 AM CDT (10:42 UTC)
Expired
May 12, 2019, 6:15 AM CDT
In force
33 min
Issued by
NWS New Orleans, LA
Area
Storm-based polygon
Tornado
Possible
Hail
1.0 in
Wind
60.0 mph

County Terrebonne Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 10.7 hours before the alert went out and 150 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Slidell Radar S, LA at 00:00Z on 2019-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2328 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Slidell Radar S, LA at 00:00Z on 2019-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 130 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
2328 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
785 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
130 m²/s²
0-3 km storm-relative helicity
130 m²/s²
Significant tornado parameter
1.3
Supercell composite
8.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS New Orleans, LA wrote its last area forecast discussion before this severe thunderstorm warning went out at May 12, 3:39 AM CDT, 2 hours 3 minutes earlier.

Area forecast discussion, May 12, 3:39 AM CDT, 2 hours 3 minutes before
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Hazardous weather outlook, May 12, 4:19 AM CDT, 1 hour 23 minutes before
Hazardous Weather Outlook
National Weather Service New Orleans LA
419 AM CDT Sun May 12 2019

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>082-122130-
Lake Pontchartrain and Lake Maurepas-Mississippi Sound-
Lake Borgne-Chandeleur Sound-Breton Sound-
Coastal Waters from Port Fourchon LA to Lower Atchafalaya River
LA out 20 nm-
Coastal waters from the Southwest Pass of the Mississippi River
to Port Fourchon Louisiana out 20 NM-
Coastal Waters from Boothville LA to Southwest Pass of the
Mississippi River out 20 nm-
Coastal waters from Pascagoula Mississippi to Stake Island out
20 NM-
Coastal waters from Port Fourchon Louisiana to Lower Atchafalaya
River LA from 20 to 60 NM-
Coastal waters from Southwest Pass of the Mississippi River to
Port Fourchon Louisiana from 20 to 60 NM-
Coastal Waters from Stake Island LA to Southwest Pass of the
Mississippi River from 20 to 60 nm-
Coastal waters from Pascagoula Mississippi to Stake Island
Louisiana out 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-
419 AM CDT Sun May 12 2019

This Hazardous Weather Outlook is for portions of Southeast
Louisiana...South Mississippi and the adjacent coastal waters.

.DAY ONE...Today and Tonight

A Flash Flood Watch is in effect through 1pm CDT for Southern and
Coastal Mississippi and southeast Louisiana...except the
immediate Louisiana coast. There is a moderate risk for life
threatening flash flooding. Additional rainfall amounts up to 2 to
4 inches will be possible this morning and early afternoon.

A few of the strong to severe storms will be possible producing
gusty winds, frequent lightning, and heavy downpours of rain.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

No significant hazards are likely through the period.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed through the weekend. Please
report any flooded roadways to local law enforcement.

In the hours before

Special weather statement, May 12, 3:38 AM CDT, 2 hours 4 minutes before
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Special weather statement, May 12, 4:33 AM CDT, 1 hour 9 minutes before
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Local storm report, May 12, 4:46 AM CDT, 56 minutes before
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Special weather statement, May 12, 5:14 AM CDT, 28 minutes before
Special Weather Statement
National Weather Service New Orleans LA
514 AM CDT Sun May 12 2019

LAZ059-065>067-121115-
Lower Terrebonne-Upper Terrebonne-Lower Lafourche-Upper Lafourche-
514 AM CDT Sun May 12 2019

...A STRONG THUNDERSTORM WILL AFFECT EAST CENTRAL TERREBONNE AND
CENTRAL LAFOURCHE PARISHES...

At 514 AM CDT, a strong thunderstorm was located 13 miles southwest
of Bayou Cane, or 13 miles southwest of Houma, moving east at 35 mph.

Winds in excess of 30 mph are possible with this storm.

Locations impacted include...
Houma, Larose, Cut Off, Galliano, Golden Meadow, Chauvin, Dulac and
Montegut.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 2933 9035 2934 9035 2934 9043 2935 9043
      2933 9048 2934 9051 2936 9051 2934 9052
      2935 9053 2934 9054 2938 9099 2956 9098
      2959 9023 2932 9024
TIME...MOT...LOC 1014Z 271DEG 29KT 2948 9090

24/RR
Special weather statement, May 12, 5:17 AM CDT, 25 minutes before
Special Weather Statement
National Weather Service New Orleans LA
517 AM CDT Sun May 12 2019

LAZ059>065-069-070-121115-
Orleans-Lower Plaquemines-Upper St. Bernard-St. Charles-Upper
Terrebonne-Lower St. Bernard-Upper Lafourche-Upper Plaquemines-Upper
Jefferson-
517 AM CDT Sun May 12 2019

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT ST. BERNARD...SOUTHERN
ST. CHARLES...ORLEANS...NORTH CENTRAL TERREBONNE...NORTHEASTERN
LAFOURCHE...NORTHERN JEFFERSON AND NORTHWESTERN PLAQUEMINES
PARISHES...

At 517 AM CDT, radar indicated strong thunderstorms were located
along a line extending from near Lake Catherine to near Gray.
Movement was southeast at 15 mph.

Winds in excess of 30 mph are possible with these storms.

Locations impacted include...
New Orleans, Houma, Chalmette, Avondale, Marrero, Harvey, Timberlane,
Belle Chasse, Larose, Jefferson, Gretna, Harahan, Westwego, Lockport,
Jean Lafitte, Mathews, Lake Catherine, Poydras, Raceland and Estelle.

Torrential rainfall is also occurring with these storms, and may
cause localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 2958 9094 3017 8968 3015 8963 3006 8973
      3002 8972 3004 8982 3000 8985 2998 8985
      2993 8981 2996 8973 2992 8975 2987 8970
      2989 8959 2999 8958 3008 8949 3004 8938
      2998 8946 2996 8938 2991 8938 2959 9022
TIME...MOT...LOC 1017Z 310DEG 14KT 3011 8967 2966 9087

24/RR
Local storm report, May 12, 5:42 AM CDT, 0 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
542 AM CDT SUN MAY 12 2019

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

0438 AM     TSTM WND DMG     DESTREHAN               29.96N 90.37W
05/12/2019                   ST. CHARLES        LA   EMERGENCY MNGR

            ST CHARLES PARISH EOC REPORTED POWER OUTAGES ON THE EAST
            BANK, DESTREHAN AND NORCO AREAS. EVENT TIME ESTIMATED
            BASED ON RADAR.

0537 AM     FLASH FLOOD      DESTREHAN               29.96N 90.37W
05/12/2019                   ST. CHARLES        LA   EMERGENCY MNGR

            STREET FLOODING OCCURRING AT THIS TIME IN THE DESTREHAN
            AND NORCO AREAS.

&&

BWAGNER

The office that day

Everything else NWS New Orleans, LA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 11, 9:13 PM CDTSpecial Marine WarningLIX47 min
May 11, 10:39 PM CDTSpecial Weather StatementLIXSaint Charles36 min
May 11, 10:41 PM CDTSpecial Marine WarningLIX49 min
May 11, 10:46 PM CDTSpecial Weather StatementLIXAssumption, Saint James44 min
May 11, 10:54 PM CDTSevere Thunderstorm WarningLIXAscension, Assumption, Saint James36 min
May 11, 11:16 PM CDTSpecial Weather StatementLIXOrleans44 min
May 11, 11:23 PM CDTSpecial Marine WarningLIX37 min
May 11, 11:36 PM CDTAreal Flood AdvisoryLIXJefferson, Orleans114 min
May 11, 11:42 PM CDTSpecial Weather StatementLIXOrleans48 min
May 11, 11:51 PM CDTSpecial Marine WarningLIX39 min
May 11, 11:54 PM CDTSpecial Marine WarningLIX36 min
May 12, 12:03 AM CDTSpecial Weather StatementLIXOrleans27 min
May 12, 12:24 AM CDTSpecial Marine WarningLIX51 min
May 12, 12:47 AM CDTFlash Flood WarningLIXJefferson, Orleans, Plaquemines, Saint Bernard118 min
May 12, 1:14 AM CDTSpecial Marine WarningLIX61 min
May 12, 2:14 AM CDTSpecial Marine WarningLIX61 min
May 12, 2:41 AM CDTSpecial Weather StatementLIXLivingston49 min
May 12, 2:44 AM CDTSevere Thunderstorm WarningLIXAscension, East Baton Rouge, Livingston31 min
May 12, 3:01 AM CDTSevere Thunderstorm WarningLIXAscension, Iberville29 min
May 12, 3:12 AM CDTSpecial Weather StatementLIXLivingston, Tangipahoa63 min
May 12, 3:18 AM CDTSpecial Marine WarningLIX27 min
May 12, 3:38 AM CDTSpecial Weather StatementLIXSaint John the Baptist67 min
May 12, 3:47 AM CDTSpecial Marine WarningLIX58 min
May 12, 3:52 AM CDTSpecial Marine WarningLIX38 min
May 12, 4:10 AM CDTSevere Thunderstorm WarningLIXJefferson, Orleans, Saint Bernard, Saint Charles, Saint James, Saint John the Baptist65 min
May 12, 4:27 AM CDTSpecial Marine WarningLIX33 min
May 12, 4:29 AM CDTSpecial Marine WarningLIX61 min
May 12, 4:33 AM CDTSpecial Weather StatementLIXSaint Tammany57 min
May 12, 5:10 AM CDTSpecial Marine WarningLIX65 min
May 12, 5:14 AM CDTSpecial Weather StatementLIXLafourche61 min
May 12, 5:17 AM CDTSpecial Weather StatementLIXSaint Charles58 min
May 12, 5:20 AM CDTSpecial Marine WarningLIX25 min
May 12, 5:35 AM CDTFlash Flood WarningLIXJefferson, Orleans, Plaquemines, Saint Bernard, Saint Charles3 hr
May 12, 5:48 AM CDTSpecial Marine WarningLIX87 min
May 12, 5:54 AM CDTSpecial Marine WarningLIX96 min
May 12, 6:10 AM CDTSpecial Marine WarningLIX35 min
May 12, 6:31 AM CDTSevere Thunderstorm WarningLIXJefferson, Lafourche, Terrebonne44 min
May 12, 7:16 AM CDTSpecial Marine WarningLIX29 min
May 12, 8:13 AM CDTSpecial Marine WarningLIX92 min
May 12, 8:42 AM CDTFlash Flood WarningLIXJefferson, Orleans, Saint Charles2 hr
May 12, 9:42 AM CDTSpecial Marine WarningLIX63 min
May 12, 9:52 AM CDTSpecial Marine WarningLIX53 min
May 12, 10:49 AM CDTSpecial Marine WarningLIX86 min
May 11, 7:15 PM CDTFlash Flood WarningLIXHancock, Harrison12 hr
May 11, 8:09 PM CDTSpecial Weather StatementLIXJackson36 min
May 11, 8:24 PM CDTRiver Flood WarningLIXHarrison44 hr
May 11, 8:42 PM CDTSpecial Weather StatementLIXJackson33 min
May 11, 9:06 PM CDTRiver Flood WarningLIXJackson9 days
May 11, 11:02 PM CDTFlash Flood WarningLIXPearl River6 hr
May 12, 7:52 AM CDTFlash Flood WarningLIXHancock, Harrison, Pearl River3 hr
May 12, 10:58 AM CDTAreal Flood WarningLIXHancock, Harrison, Pearl River6 hr
May 12, 4:56 PM CDTAreal Flood WarningLIXHarrison6 hr

Nearby

Severe Thunderstorm Warnings in Louisiana, 2019Every severe thunderstorm warning in 2019

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive.