Alert archive / Louisiana / Special Weather Statements in 2021

Special Weather Statement, NWS New Orleans, LA

July 10, 2021Orleans Parish, Louisiana

NWS New Orleans, LA issued this special weather statement at Jul 10, 2021, 4:40 PM CDT for Orleans Parish, Louisiana. It was in force for 35 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 10, 2021, 4:40 PM CDT (21:40 UTC)
Expired
Jul 10, 2021, 5:15 PM CDT
In force
35 min
Issued by
NWS New Orleans, LA

County Orleans Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 9.7 hours before the alert went out and 32 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 12:00Z on 2021-07-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2543 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 12:00Z on 2021-07-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 square meters per square second.1939Sfc1 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
2543 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
615 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
26 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement 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 special weather statement went out at Jul 10, 3:57 PM CDT, 43 minutes earlier.

Area forecast discussion, Jul 10, 3:57 PM CDT, 43 minutes before
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In the hours before

Special weather statement, Jul 10, 12:31 PM CDT, 4 hours 9 minutes before
Special Weather Statement
National Weather Service New Orleans LA
1231 PM CDT Sat Jul 10 2021

LAZ075-MSZ077-080-101800-
Northwest St. Tammany-Hancock-Pearl River-
1231 PM CDT Sat Jul 10 2021

...A STRONG THUNDERSTORM WILL AFFECT EAST CENTRAL ST. TAMMANY
PARISH...NORTHWESTERN HANCOCK AND SOUTHWESTERN PEARL RIVER
COUNTIES...

At 1231 PM CDT, a strong thunderstorm was located over Picayune,
moving northeast at 10 mph.

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

Locations impacted include...
Picayune and Mcneil.

This includes the following Interstates...
 Interstate 59 in Louisiana between mile markers 8 and 11.
 Interstate 59 in Mississippi between mile markers 1 and 18.

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 3038 8970 3054 8987 3072 8958 3049 8942
TIME...MOT...LOC 1731Z 238DEG 9KT 3053 8967

MSW
Special weather statement, Jul 10, 1:44 PM CDT, 2 hours 56 minutes before
Special Weather Statement
National Weather Service New Orleans LA
144 PM CDT Sat Jul 10 2021

MSZ081-082-101915-
Jackson-Harrison-
144 PM CDT Sat Jul 10 2021

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN HARRISON AND
NORTHERN JACKSON COUNTIES...

At 144 PM CDT, a strong thunderstorm was located 9 miles north of
Latimer, or 13 miles north of St. Martin, moving northeast at 25 mph.

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

Locations impacted include...
Hurley, Wade, Latimer and Vancleave.

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 3061 8845 3049 8889 3066 8896 3068 8893
      3067 8889 3071 8889 3074 8885 3074 8854
TIME...MOT...LOC 1844Z 239DEG 20KT 3063 8884

MSW
Special weather statement, Jul 10, 2:54 PM CDT, 1 hour 46 minutes before
Special Weather Statement
National Weather Service New Orleans LA
254 PM CDT Sat Jul 10 2021

LAZ072-102030-
Southern Tangipahoa-
254 PM CDT Sat Jul 10 2021

...A STRONG THUNDERSTORM WILL AFFECT SOUTHERN TANGIPAHOA PARISH...

At 254 PM CDT, a strong thunderstorm was located over Ponchatoula, or
near Hammond. The storm is nearly stationary.

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

Locations impacted include...
Hammond, Ponchatoula, Robert and Natalbany.

This includes the following Interstates...
 Interstate 12 between mile markers 36 and 51.
 Interstate 55 in Louisiana between mile markers 18 and 32.

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 3062 9041 3046 9024 3040 9024 3032 9040
      3045 9055 3046 9055
TIME...MOT...LOC 1954Z 227DEG 4KT 3044 9042

MSW
Local storm report, Jul 10, 3:07 PM CDT, 1 hour 33 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
307 PM CDT SAT JUL 10 2021

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

0153 PM     MARINE TSTM WIND 6 WSW EAST NEW ORLEANS  30.05N 90.03W
07/10/2021  M39 MPH          ORLEANS            LA   ASOS

            KNEW MEASURED A WIND GUST OF 39 MPH.

&&
Special weather statement, Jul 10, 3:09 PM CDT, 1 hour 31 minutes before
Special Weather Statement
National Weather Service New Orleans LA
309 PM CDT Sat Jul 10 2021

LAZ072-075-102045-
Northwest St. Tammany-Southern Tangipahoa-
309 PM CDT Sat Jul 10 2021

...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN ST. TAMMANY AND
SOUTHEASTERN TANGIPAHOA PARISHES...

At 309 PM CDT, a strong thunderstorm was located near Covington. The
storm is nearly stationary.

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

Locations impacted include...
Covington, Abita Springs and Madisonville.

This includes Interstate 12 between mile markers 50 and 67.

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 3046 8990 3036 9012 3039 9019 3038 9022
      3047 9032 3066 9014
TIME...MOT...LOC 2009Z 225DEG 3KT 3046 9019

MSW
Special weather statement, Jul 10, 4:40 PM CDT, 0 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Jul 10, 7:17 AM CDTSpecial Marine WarningLIX28 min
Jul 10, 7:33 AM CDTSpecial Marine WarningLIX27 min
Jul 10, 7:58 AM CDTSpecial Marine WarningLIX47 min
Jul 10, 9:20 AM CDTSpecial Marine WarningLIX55 min
Jul 10, 1:59 PM CDTSpecial Marine WarningLIX24 min
Jul 10, 2:54 PM CDTSpecial Weather StatementLIXTangipahoa36 min
Jul 10, 3:09 PM CDTSpecial Weather StatementLIXSaint Tammany36 min
Jul 10, 3:53 PM CDTSpecial Marine WarningLIX67 min
Jul 10, 5:12 PM CDTSpecial Marine WarningLIX48 min
Jul 10, 5:53 PM CDTAreal Flood AdvisoryLIXLivingston, Saint Helena, Tangipahoa111 min
Jul 10, 6:35 AM CDTSpecial Weather StatementLIXHancock25 min
Jul 10, 6:54 AM CDTRiver Flood WarningLIXHarrison13 hr
Jul 10, 7:18 AM CDTSpecial Weather StatementLIXHarrison27 min
Jul 10, 7:55 AM CDTSpecial Weather StatementLIXHarrison50 min
Jul 10, 12:28 PM CDTSpecial Weather StatementLIXWilkinson32 min
Jul 10, 12:31 PM CDTSpecial Weather StatementLIXHancock29 min
Jul 10, 1:44 PM CDTSpecial Weather StatementLIXJackson31 min

Nearby

Special Weather Statements in Louisiana, 2021Every special weather statement in 2021

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.