Alert archive / Louisiana / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 143, NWS New Orleans, LA

October 22, 2017Plaquemines Parish, Saint Bernard Parish, Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at Oct 22, 2017, 12:37 PM CDT for Plaquemines Parish, Saint Bernard Parish, Louisiana. It was in force for 23 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: Oct 22, 2017, 12:37 PM CDT (17:37 UTC)
Expired: Oct 22, 2017, 1:00 PM CDT
In force: 23 min
Issued by: NWS New Orleans, LA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Plaquemines Parish, LA, Saint Bernard Parish, LA

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 5.6 hours before the alert went out and 291 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 72 J/kg
Mixed-layer CIN: -332 J/kg
Mixed-layer LCL: 1526 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 136 m²/s²
0-3 km storm-relative helicity: 218 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

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 Oct 22, 12:20 PM CDT, 17 minutes earlier.

Area forecast discussion, Oct 22, 12:20 PM CDT, 17 minutes before

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Hazardous weather outlook, Oct 22, 10:59 AM CDT, 1 hour 38 minutes before

Hazardous Weather Outlook
National Weather Service New Orleans LA
1059 AM CDT Sun Oct 22 2017

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>082-230400-
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-
1059 AM CDT Sun Oct 22 2017

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

.DAY ONE...Today and Tonight

Scattered to numerous thunderstorms are expected today and
tonight. Some of the thunderstorms will be capable of producing
frequent lightning, periods of torrential rainfall, and strong
gusty winds. There is a marginal risk of severe weather, primarily
during the afternoon and evening hours.

A Flash Flood Watch is in effect for portions of east central
Louisiana and extreme southwest Mississippi through this
afternoon. Additional rainfall amounts of up to one inch are
possible.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

Small Craft Advisory conditions are likely to develop across the
coastal waters during the first half of the work week.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed this afternoon and evening in
support of severe thunderstorm and flash flood monitoring.

32

In the hours before

Special weather statement, Oct 22, 11:07 AM CDT, 1 hour 30 minutes before

Special Weather Statement
National Weather Service New Orleans LA
1107 AM CDT SUN OCT 22 2017

LAZ039-040-049-050-056>065-071-072-MSZ071-221630-
Orleans-St. Charles-Livingston-Ascension-Upper Terrebonne-Southern
Tangipahoa-St. James-St. Tammany-Washington-Upper St.
Bernard-Northern Tangipahoa-Assumption-St. John The Baptist-Upper
Lafourche-Upper Plaquemines-Upper Jefferson-Walthall-
1107 AM CDT SUN OCT 22 2017

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT NORTHWESTERN ST.
BERNARD...ORLEANS...ST. TAMMANY...NORTHEASTERN TERREBONNE...NORTHERN
LAFOURCHE...JEFFERSON...ST. JOHN THE BAPTIST...EASTERN ST. JAMES...
ST. CHARLES...SOUTHEASTERN LIVINGSTON...SOUTHERN TANGIPAHOA...
NORTHWESTERN PLAQUEMINES...SOUTHEASTERN ASSUMPTION...WASHINGTON
PARISHES IN SOUTHEASTERN LOUISIANA AND WALTHALL COUNTIES...

At 1105 AM CDT, radar indicated strong thunderstorms were located
along a line extending from near Kokomo to 12 miles south of
Springfield to near Labadieville. Movement was southeast at 40 mph.

Winds in excess of 40 mph are possible with these storms.

Locations impacted include...
New Orleans, Houma, Slidell, Hammond, Thibodaux, Bogalusa, Covington,
Franklinton, Reserve, Metairie, Hahnville, Laplace, Marrero,
Chalmette, Avondale, Larose, Sandy Hook, Harvey, East New Orleans and
Timberlane.

LAT...LON 3114 9001 3100 8973 3066 8985 3031 8963
      3017 8972 3039 9020 3014 9043 3002 9013
      3016 8970 2985 8984 2956 9019 2957 9091
      2972 9110 3030 9056 3018 9047 3019 9046
      3022 9044 3032 9043 3031 9056 3134 9004
TIME...MOT...LOC 1605Z 306DEG 42KT 3126 9001 3026 9047 2976 9101

Local storm report, Oct 22, 11:59 AM CDT, 38 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1159 AM CDT SUN OCT 22 2017

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

1130 AM     TSTM WND DMG     LAPLACE                 30.07N 90.47W
10/22/2017                   ST. JOHN THE BAPTI LA   TRAINED SPOTTER

            POWERLINES BLOWN DOWN ALONG LA 51 IN LA PLACE. TIME
            ESTIMATED FROM RADAR

&&

AK

Local storm report, Oct 22, 12:12 PM CDT, 25 minutes before

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Local storm report, Oct 22, 12:23 PM CDT, 14 minutes before

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Local storm report, Oct 22, 12:29 PM CDT, 8 minutes before

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Local storm report, Oct 22, 12:33 PM CDT, 4 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 21, 8:05 PM CDT	Areal Flood Advisory	LIX	Iberville, Pointe Coupee, West Baton Rouge	3 hr
Oct 21, 8:45 PM CDT	Flash Flood Watch	LIX	East Feliciana, Iberville, Pointe Coupee, West Baton Rouge, West Feliciana	19 hr
Oct 21, 10:24 PM CDT	Tornado Warning	LIX	East Baton Rouge, East Feliciana	16 min
Oct 21, 11:08 PM CDT	Special Weather Statement	LIX	East Feliciana	37 min
Oct 21, 11:24 PM CDT	Areal Flood Advisory	LIX	East Feliciana, Pointe Coupee, West Feliciana	2 hr
Oct 22, 1:26 AM CDT	Flash Flood Warning	LIX	East Feliciana, West Feliciana	3 hr
Oct 22, 1:46 AM CDT	Severe Thunderstorm Warning	LIX	East Feliciana	29 min
Oct 22, 2:33 AM CDT	Severe Thunderstorm Warning	LIX	East Feliciana	42 min
Oct 22, 3:31 AM CDT	Areal Flood Advisory	LIX	East Feliciana, Saint Helena	119 min
Oct 22, 4:00 AM CDT	Flash Flood Warning	LIX	East Feliciana	3 hr
Oct 22, 4:24 AM CDT	Tornado Warning	LIX	Saint Helena	51 min
Oct 22, 5:20 AM CDT	Flash Flood Warning	LIX	East Feliciana, Saint Helena	115 min
Oct 22, 7:27 AM CDT	Areal Flood Warning	LIX	East Feliciana, West Feliciana	6 hr
Oct 22, 7:31 AM CDT	Special Weather Statement	LIX	Saint Tammany, Washington	29 min
Oct 22, 7:40 AM CDT	Special Marine Warning	LIX		35 min
Oct 22, 8:14 AM CDT	Special Marine Warning	LIX		61 min
Oct 22, 8:26 AM CDT	Special Weather Statement	LIX	Orleans	34 min
Oct 22, 9:12 AM CDT	Special Marine Warning	LIX		48 min
Oct 22, 9:38 AM CDT	Special Weather Statement	LIX	East Baton Rouge, East Feliciana, West Baton Rouge	82 min
Oct 22, 9:55 AM CDT	Special Marine Warning	LIX		65 min
Oct 22, 10:15 AM CDT	Special Weather Statement	LIX	Ascension, Iberville, Livingston, Saint Helena, Tangipahoa	75 min
Oct 22, 10:44 AM CDT	Areal Flood Warning	LIX	Pointe Coupee	3 hr
Oct 22, 10:48 AM CDT	Special Marine Warning	LIX		87 min
Oct 22, 10:58 AM CDT	Special Marine Warning	LIX		92 min
Oct 22, 11:07 AM CDT	Special Weather Statement	LIX	Orleans, Saint Charles, Saint James, Saint John the Baptist, Saint Tammany, Washington	23 min
Oct 22, 11:26 AM CDT	Severe Thunderstorm Warning	LIX	Jefferson, Saint Charles, Saint John the Baptist	51 min
Oct 22, 11:57 AM CDT	Severe Thunderstorm Warning	LIX	Orleans, Saint Tammany, Washington	48 min
Oct 22, 12:02 PM CDT	Severe Thunderstorm Warning	LIX	Jefferson, Lafourche, Plaquemines, Saint Bernard, Saint Charles	28 min
Oct 22, 12:11 PM CDT	Severe Thunderstorm Warning	LIX	Jefferson, Lafourche, Plaquemines, Terrebonne	64 min
Oct 22, 12:16 PM CDT	Special Marine Warning	LIX		89 min
Oct 22, 12:30 PM CDT	Special Marine Warning	LIX		90 min
Oct 22, 12:47 PM CDT	Special Marine Warning	LIX		88 min
Oct 22, 1:46 PM CDT	Special Marine Warning	LIX		89 min
Oct 22, 2:11 PM CDT	Special Marine Warning	LIX		2 hr
Oct 22, 2:48 PM CDT	Special Marine Warning	LIX		117 min
Oct 22, 2:50 PM CDT	Special Marine Warning	LIX		115 min
Oct 22, 3:20 PM CDT	Special Marine Warning	LIX		85 min
Oct 22, 3:46 PM CDT	Small Craft Advisory	LIX		26 hr
Oct 22, 1:07 AM CDT	Special Weather Statement	LIX	Wilkinson	53 min
Oct 22, 2:00 AM CDT	Flash Flood Warning	LIX	Wilkinson	3 hr
Oct 22, 2:09 AM CDT	Special Weather Statement	LIX	Amite	51 min
Oct 22, 2:27 AM CDT	Special Weather Statement	LIX	Amite	48 min
Oct 22, 3:04 AM CDT	Special Weather Statement	LIX	Amite	26 min
Oct 22, 3:52 AM CDT	Special Weather Statement	LIX	Amite	53 min
Oct 22, 4:59 AM CDT	Severe Thunderstorm Warning	LIX	Pike	61 min
Oct 22, 5:26 AM CDT	Tornado Warning	LIX	Pike	34 min
Oct 22, 7:37 AM CDT	Tornado Warning	LIX	Hancock, Harrison	23 min
Oct 22, 7:41 AM CDT	Special Weather Statement	LIX	Harrison	34 min
Oct 22, 7:54 AM CDT	Tornado Warning	LIX	Harrison	20 min
Oct 22, 8:41 AM CDT	Tornado Warning	LIX	Harrison	49 min
Oct 22, 9:09 AM CDT	Special Weather Statement	LIX	Hancock	36 min
Oct 22, 9:26 AM CDT	Flash Flood Warning	LIX	Hancock, Harrison	3 hr
Oct 22, 9:58 AM CDT	Special Weather Statement	LIX	Harrison	32 min
Oct 22, 10:52 AM CDT	Flash Flood Warning	LIX	Jackson	3 hr
Oct 22, 11:19 AM CDT	Tornado Warning	LIX	Jackson	10 min
Oct 22, 12:08 PM CDT	Tornado Warning	LIX	Jackson	11 min
Oct 22, 12:38 PM CDT	River Flood Warning	LIX	Harrison	48 hr
Oct 22, 12:38 PM CDT	River Flood Warning	LIX	Harrison	30 hr
Oct 22, 1:02 PM CDT	Special Weather Statement	LIX	Harrison, Jackson	28 min
Oct 22, 1:45 PM CDT	Special Weather Statement	LIX	Harrison, Jackson	60 min
Oct 22, 3:41 PM CDT	Areal Flood Advisory	LIX	Jackson	64 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 2017 Every severe thunderstorm warning in 2017

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.