Alert archive / Louisiana / Special Marine Warnings in 2021

Special Marine Warning 310, NWS New Orleans, LA

June 13, 2021

NWS New Orleans, LA issued this special marine warning at Jun 13, 2021, 2:45 PM CDT. It was in force for 45 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
Jun 13, 2021, 2:45 PM CDT (19:45 UTC)
Expired
Jun 13, 2021, 3:30 PM CDT
In force
45 min
Issued by
NWS New Orleans, LA
Area
Storm-based polygon
Hail
0.0 in
Wind
34.0 mph

The radar

The Mobile radar (KMOB), 108 km from the middle of the area, began a volume at 19:45 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 7.8 hours before the alert went out and 41 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 2021-06-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2482 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 2021-06-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 43 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
2482 J/kg
Mixed-layer CIN
-20 J/kg
Mixed-layer LCL
802 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
52 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.3

Open this sounding in Storm Lab

The text

As transmitted.

882 
WHUS54 KLIX 131945
SMWLIX
GMZ532-536-132030-
/O.NEW.KLIX.MA.W.0310.210613T1945Z-210613T2030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service New Orleans LA
245 PM CDT Sun Jun 13 2021

The National Weather Service in New Orleans has issued a

* Special Marine Warning for...
  Chandeleur Sound...
  Mississippi Sound...

* Until 330 PM CDT.

* At 245 PM CDT, a strong thunderstorm was located near Cat Island,
  moving southwest at 5 knots.

  HAZARD...Wind gusts 34 knots or greater.

  SOURCE...Radar.

  IMPACT...Expect wind gusts in excess of 34 knots and suddenly 
           higher waves. Boats could sustain damage or capsize. Make 
           sure all on board are wearing life jackets. Return to 
           safe harbor if possible.

* Locations impacted include...
  Pass Christian.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor immediately as gusty winds and high waves are
expected.

&&

LAT...LON 3034 8927 3033 8929 3030 8929 3035 8914
      3020 8911 3015 8914 3011 8930 3029 8935
      3032 8933 3035 8934 3035 8938 3037 8935
      3038 8931
TIME...MOT...LOC 1945Z 061DEG 7KT 3025 8917 

HAIL...0.00IN
WIND...>34KTS

$$

KLG
2 follow-up statements
855 
FZUS74 KLIX 131957
MWSLIX

Marine Weather Statement
National Weather Service New Orleans LA
257 PM CDT Sun Jun 13 2021

GMZ532-536-132030-
/O.CON.KLIX.MA.W.0310.000000T0000Z-210613T2030Z/
257 PM CDT Sun Jun 13 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 330 PM CDT...

For the following areas...
Chandeleur Sound...
Mississippi Sound...

At 257 PM CDT, a strong thunderstorm was located near Pass Christian,
moving southwest at 5 knots.

HAZARD...Wind gusts to nearly 50 knots and small hail.

SOURCE...Radar indicated.

IMPACT...Expect wind gusts in excess of 34 knots and suddenly higher 
         waves. Boats could sustain damage or capsize. Make sure all 
         on board are wearing life jackets. Return to safe harbor if 
         possible.

Locations impacted include...
Pass Christian.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor immediately as gusty winds and high waves are
expected.

&&

LAT...LON 3034 8927 3033 8929 3030 8929 3035 8914
      3020 8911 3015 8914 3011 8930 3029 8935
      3032 8933 3035 8934 3035 8938 3037 8935
      3038 8931
TIME...MOT...LOC 1957Z 061DEG 7KT 3024 8919 

HAIL...<.75IN
WIND...49KTS

$$

KLG
406 
FZUS74 KLIX 132019
MWSLIX

Marine Weather Statement
National Weather Service New Orleans LA
319 PM CDT Sun Jun 13 2021

GMZ536-132028-
/O.CAN.KLIX.MA.W.0310.000000T0000Z-210613T2030Z/
319 PM CDT Sun Jun 13 2021

...THE SPECIAL MARINE WARNING IS CANCELLED...

The affected areas were...
Chandeleur Sound...

The thunderstorm has moved out of the warned area and no longer 
poses a significant threat to boaters.

A Severe Thunderstorm Watch remains in effect until 700 PM CDT for
southern Mississippi...and the adjacent coastal waters.

LAT...LON 3034 8927 3033 8929 3030 8929 3031 8924
      3014 8924 3011 8930 3029 8935 3032 8933
      3035 8934 3035 8938 3037 8935 3038 8931
TIME...MOT...LOC 2018Z 061DEG 7KT 3022 8923 

$$

GMZ532-132030-
/O.CON.KLIX.MA.W.0310.000000T0000Z-210613T2030Z/
319 PM CDT Sun Jun 13 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 330 PM CDT...

For the following areas...
Mississippi Sound...

At 318 PM CDT, a severe thunderstorm was located near Pass Christian,
moving southwest at 5 knots.

HAZARD...Wind gusts to 40 knots and large hail.

SOURCE...Radar indicated.

IMPACT...Expect wind gusts in excess of 34 knots and suddenly higher 
         waves. Boats could sustain damage or capsize. Make sure all 
         on board are wearing life jackets. Return to safe harbor if 
         possible. Large hail could result in injury and damage to 
         boats...vessels and oil rigs.

The severe thunderstorm will remain over mainly open waters.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor immediately as gusty winds and high waves are
expected.

&&

LAT...LON 3034 8927 3033 8929 3030 8929 3031 8924
      3014 8924 3011 8930 3029 8935 3032 8933
      3035 8934 3035 8938 3037 8935 3038 8931
TIME...MOT...LOC 2018Z 061DEG 7KT 3022 8923 

HAIL...>.75IN
WIND...40KTS

$$

KLG

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 13, 12:12 AM CDTSpecial Marine WarningLIX48 min
Jun 13, 12:58 AM CDTSpecial Marine WarningLIX62 min
Jun 13, 1:43 AM CDTSpecial Marine WarningLIX62 min
Jun 13, 9:38 AM CDTSpecial Marine WarningLIX52 min
Jun 13, 11:34 AM CDTSpecial Marine WarningLIX56 min
Jun 13, 1:04 PM CDTSpecial Weather StatementLIXJefferson41 min
Jun 13, 1:10 PM CDTSpecial Marine WarningLIX65 min
Jun 13, 2:05 PM CDTSpecial Marine WarningLIX55 min
Jun 13, 2:52 PM CDTSpecial Weather StatementLIXSaint Tammany23 min
Jun 13, 3:11 PM CDTSpecial Marine WarningLIX64 min
Jun 13, 4:03 PM CDTSevere Thunderstorm WarningLIXSaint Tammany42 min
Jun 13, 4:10 PM CDTSpecial Marine WarningLIX65 min
Jun 13, 4:18 PM CDTSpecial Marine WarningLIX57 min
Jun 13, 4:28 PM CDTSevere Thunderstorm WarningLIXSaint Tammany, Washington32 min
Jun 13, 4:33 PM CDTSpecial Weather StatementLIXSaint Bernard42 min
Jun 13, 4:44 PM CDTSpecial Weather StatementLIXSaint Tammany46 min
Jun 13, 4:55 PM CDTSpecial Weather StatementLIXJefferson35 min
Jun 13, 5:13 PM CDTSpecial Marine WarningLIX62 min
Jun 13, 5:23 PM CDTSpecial Weather StatementLIXWashington52 min
Jun 13, 5:25 PM CDTSpecial Marine WarningLIX35 min
Jun 13, 5:28 PM CDTSpecial Weather StatementLIXPlaquemines62 min
Jun 13, 5:47 PM CDTSpecial Marine WarningLIX58 min
Jun 13, 5:53 PM CDTSevere Thunderstorm WarningLIXWashington65 min
Jun 13, 5:59 PM CDTSpecial Weather StatementLIXTangipahoa31 min
Jun 13, 6:17 PM CDTSpecial Weather StatementLIXTangipahoa28 min
Jun 13, 6:19 PM CDTSpecial Marine WarningLIX56 min
Jun 13, 6:35 PM CDTSevere Thunderstorm WarningLIXSaint Tammany54 min
Jun 13, 6:41 PM CDTSpecial Weather StatementLIXSaint Helena, Tangipahoa64 min
Jun 13, 6:42 PM CDTSpecial Weather StatementLIXLafourche63 min
Jun 13, 6:48 PM CDTSpecial Weather StatementLIXTangipahoa27 min
Jun 13, 6:54 PM CDTSpecial Weather StatementLIXSaint Charles51 min
Jun 13, 6:56 PM CDTSpecial Marine WarningLIX64 min
Jun 13, 1:07 PM CDTSpecial Weather StatementLIXJackson38 min
Jun 13, 1:57 PM CDTSpecial Weather StatementLIXJackson63 min
Jun 13, 2:40 PM CDTSpecial Weather StatementLIXHancock65 min
Jun 13, 2:48 PM CDTSpecial Weather StatementLIXHancock57 min
Jun 13, 2:56 PM CDTSevere Thunderstorm WarningLIXHancock, Harrison28 min
Jun 13, 3:30 PM CDTSpecial Weather StatementLIXHancock60 min
Jun 13, 4:23 PM CDTSpecial Weather StatementLIXPearl River67 min

Nearby

Special Marine Warnings in Louisiana, 2021Every special marine warning 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; radar from the NEXRAD Level II archive.