Alert archive / Louisiana / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 14, NWS New Orleans, LA

January 21, 2017Tangipahoa Parish, Washington Parish, Louisiana; Walthall County, Mississippi

NWS New Orleans, LA issued this severe thunderstorm warning at Jan 21, 2017, 2:28 AM CST for Tangipahoa Parish, Washington Parish, Louisiana; Walthall County, Mississippi. It was in force for 32 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: Jan 21, 2017, 2:28 AM CST (08:28 UTC)
Expired: Jan 21, 2017, 3:00 AM CST
In force: 32 min
Issued by: NWS New Orleans, LA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Tangipahoa Parish, LA, Washington Parish, LA, Walthall County, MS

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jan 20, 11:00 PM CST	Tornado Watch	SPC	8 hr

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 8.5 hours before the alert went out and 91 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: 628 J/kg
Mixed-layer CIN: -28 J/kg
Mixed-layer LCL: 857 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 85 m²/s²
0-3 km storm-relative helicity: 150 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.6

Open this sounding in Storm Lab

The text

As transmitted.

047 
WUUS54 KLIX 210828
SVRLIX
LAC105-117-MSC147-210900-
/O.NEW.KLIX.SV.W.0014.170121T0828Z-170121T0900Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service New Orleans LA
228 AM CST SAT JAN 21 2017

The National Weather Service in New Orleans has issued a

* Severe Thunderstorm Warning for...
  Western Washington Parish in southeastern Louisiana...
  Northeastern Tangipahoa Parish in southeastern Louisiana...
  Southern Walthall County in southern Mississippi...

* Until 300 AM CST

* At 228 AM CST, a severe thunderstorm was located near Franklinton,
  moving northeast at 40 mph.

  HAZARD...60 mph wind gusts and quarter size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees. 

* Locations impacted include...
  Franklinton, Dexter and Wilmer. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

A tornado watch remains in effect until 700 AM CST for southeastern
Louisiana...and southern Mississippi.

LAT...LON 3111 8993 3109 8993 3109 8992 3107 8992
      3108 8984 3100 8984 3100 8978 3070 9028
      3077 9040 3100 9027 3100 9026 3101 9026
      3110 9021 3111 8994
TIME...MOT...LOC 0828Z 234DEG 37KT 3081 9024 

HAIL...1.00IN
WIND...60MPH
 
$$

AK

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 Jan 21, 12:30 AM CST, 1 hour 58 minutes earlier.

Area forecast discussion, Jan 21, 12:30 AM CST, 1 hour 58 minutes before

Area Forecast Discussion
National Weather Service New Orleans LA
1230 AM CST Sat Jan 21 2017

....SOUNDING DISCUSSION...
The profile has modified from just 6 hrs ago. It is supportive of
a large hail and increasing tornado threat. A low level jet is
developing with winds 30kts from the south by 850 mb. Winds then
veer southwest... 55 kts at 500 mb. Peak wind is 125 kts at 250
mb. Sfc to 6km shear is 60 kts. There is not a significant
inversion aloft and lapse rates are favorable at about 7 C/KM...
leading to an area of most unstable CAPE of 1500 J/KG. Worth
noting that we have fog developing out ahead of the storms and as
such the first 2000 ft are saturated under a weak cap. This will
keep too many showers from developing ahead.

Krautmann

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  77  55  68  46 /  60  60  50  30
BTR  79  56  68  47 /  50  60  50  20
ASD  78  60  69  49 /  70  60  50  20
MSY  79  60  70  52 /  70  50  40  20
GPT  75  60  69  50 /  70  60  50  30
PQL  76  60  70  51 /  60  60  50  30

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Gale Watch from Sunday morning through late Sunday night for
     LAZ068>070.

GM...Gale Watch from Sunday morning through late Sunday night for
     GMZ536-538-550-552-555-557-570-572-575-577.

     Dense Fog Advisory until 3 AM CST early this morning for GMZ532-
     534.

MS...Dense Fog Advisory until 3 AM CST early this morning for
     MSZ080>082.

GM...Gale Watch from Sunday morning through late Sunday night for
     GMZ538-550-552-555-557-570-572-575-577.

     Dense Fog Advisory until 3 AM CST early this morning for GMZ534.

&&

Hazardous weather outlook, Jan 20, 4:30 PM CST, 9 hours 58 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NEW ORLEANS LA
430 PM CST FRI JAN 20 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>082-211400-
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-
430 PM CST FRI JAN 20 2017

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

.DAY ONE...TONIGHT

AN ENHANCED RISK OF SEVERE THUNDERSTORMS EXISTS TONIGHT BEGINNING
LATE THIS EVENING. DAMAGING WINDS...LARGE HAIL AND TORNADOES WILL
ALL BE POSSIBLE ALONG WITH HEAVY RAINFALL. PLEASE STAY CURRENT ON
FORECASTS CONCERNING THIS SEVERE WEATHER SCENARIO.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

A SLIGHT RISK OF SEVERE THUNDERSTORMS WILL EXIST SATURDAY AND
SATURDAY NIGHT. ALL MODES OF SEVERE WEATHER...DAMAGING WINDS...LARGE
HAIL AND TORNADOES WILL BE POSSIBLE ALONG WITH HEAVY RAINFALL.
PLEASE STAY CURRENT ON FORECASTS CONCERNING THIS SEVERE WEATHER
SCENARIO.

A GALE WATCH HAS BEEN POSTED STARTING SUNDAY MORNING THROUGH
SUNDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

THE ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND
EMERGENCY MANAGEMENT PERSONNEL IN SUPPORT OF SEVERE WEATHER
OPERATIONS MAY BE NEEDED TONIGHT THROUGH SATURDAY NIGHT.

11

In the hours before

Special weather statement, Jan 21, 12:51 AM CST, 1 hour 37 minutes before

Special Weather Statement
National Weather Service New Orleans LA
1251 AM CST SAT JAN 21 2017

LAZ034-035-MSZ068-210730-
West Feliciana-Pointe Coupee-Wilkinson-
1251 AM CST SAT JAN 21 2017

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN WEST FELICIANA...
NORTHWESTERN POINTE COUPEE PARISHES IN SOUTHEASTERN LOUISIANA AND
CENTRAL WILKINSON COUNTIES...

At 1251 AM CST, a strong thunderstorm was located near Fort Adams, or
11 miles northeast of Simmesport, moving east at 40 mph.

Wind gusts up to 50 mph and dime size hail are possible with this
storm.

Locations impacted include...
Woodville, Dolorosa, Wakefield, Lettsworth and Fort Adams.

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 3137 9122 3088 9131 3087 9180 3100 9178
      3104 9172 3104 9165 3097 9166 3104 9156
      3107 9156 3111 9163 3123 9157 3124 9154
      3122 9153 3123 9149 3126 9148 3128 9150
      3129 9147 3132 9146 3131 9142 3136 9130
TIME...MOT...LOC 0651Z 255DEG 35KT 3106 9164

AK

Special weather statement, Jan 21, 1:48 AM CST, 40 minutes before

Special Weather Statement
National Weather Service New Orleans LA
148 AM CST SAT JAN 21 2017

MSZ069-210815-
Amite-
148 AM CST SAT JAN 21 2017

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN AMITE COUNTY...

At 148 AM CST, a strong thunderstorm was located 7 miles north of
Gloster, or 16 miles northwest of Liberty, moving east at 45 mph.

Wind gusts up to 50 mph and dime size hail are possible with this
storm.

Locations impacted include...
Gloster, Smithdale and Crosby.

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 3135 9063 3128 9063 3115 9106 3128 9106
      3129 9108 3132 9109 3134 9107 3133 9106
      3134 9104 3133 9103 3135 9102 3134 9099
      3135 9098
TIME...MOT...LOC 0748Z 251DEG 37KT 3130 9103

AK

Special weather statement, Jan 21, 1:51 AM CST, 37 minutes before

Special Weather Statement
National Weather Service New Orleans LA
151 AM CST SAT JAN 21 2017

LAZ039-050-071-072-210830-
Livingston LA-Southern Tangipahoa LA-Northern Tangipahoa LA-
Washington LA-
151 AM CST SAT JAN 21 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN WASHINGTON...CENTRAL
TANGIPAHOA AND NORTHEASTERN LIVINGSTON PARISHES UNTIL 230 AM CST...

At 151 AM CST, Doppler radar was tracking a strong thunderstorm near
Albany, or 8 miles northwest of Hammond, moving northeast at 45 mph.

Nickel size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Hammond, Franklinton, Amite, Amite City, Independence, Roseland,
Albany, Wilmer, Mount Herman, Natalbany and Tickfaw.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

&&

A tornado watch remains in effect until 700 AM CST for southeastern
Louisiana.

LAT...LON 3099 8999 3044 9054 3052 9067 3065 9058
      3065 9057 3068 9057 3100 9035
TIME...MOT...LOC 0751Z 214DEG 41KT 3056 9058

The office that day

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

Issued	Product	Office	Counties	Lasted
Jan 20, 10:53 PM CST	Marine Dense Fog Advisory	LIX		4 hr
Jan 20, 11:01 PM CST	Severe Thunderstorm Warning	LIX	Pointe Coupee, West Feliciana	29 min
Jan 20, 11:15 PM CST	Tornado Warning	LIX	Pointe Coupee, West Feliciana	30 min
Jan 20, 11:43 PM CST	Tornado Warning	LIX	West Feliciana	32 min
Jan 21, 1:06 AM CST	Severe Thunderstorm Warning	LIX	Pointe Coupee, West Feliciana	24 min
Jan 21, 1:41 AM CST	Severe Thunderstorm Warning	LIX	Pointe Coupee, West Feliciana	34 min
Jan 21, 1:51 AM CST	Special Weather Statement	LIX	Tangipahoa	39 min
Jan 21, 2:14 AM CST	Severe Thunderstorm Warning	LIX	East Baton Rouge, East Feliciana, Pointe Coupee, Saint Helena, West Feliciana	46 min
Jan 21, 2:20 AM CST	Tornado Warning	LIX	Livingston, Saint Helena, Tangipahoa	25 min
Jan 21, 2:48 AM CST	Tornado Warning	LIX	East Baton Rouge, East Feliciana, Saint Helena	10 min
Jan 21, 2:57 AM CST	Severe Thunderstorm Warning	LIX	Washington	33 min
Jan 21, 2:57 AM CST	Severe Thunderstorm Warning	LIX	Saint Helena, Tangipahoa, Washington	48 min
Jan 21, 3:02 AM CST	Tornado Warning	LIX	Washington	13 min
Jan 21, 3:04 AM CST	Tornado Warning	LIX	Washington	15 min
Jan 21, 3:28 AM CST	Areal Flood Advisory	LIX	East Baton Rouge, Iberville, Pointe Coupee, West Baton Rouge	2 hr
Jan 21, 3:37 AM CST	Special Weather Statement	LIX	Saint Helena	38 min
Jan 21, 3:40 AM CST	Small Craft Advisory	LIX		35 hr
Jan 21, 4:45 AM CST	Special Weather Statement	LIX	Ascension, Livingston, Tangipahoa	60 min
Jan 21, 5:00 AM CST	Special Weather Statement	LIX	Washington	30 min
Jan 21, 5:22 AM CST	Severe Thunderstorm Warning	LIX	Saint Tammany, Washington	38 min
Jan 21, 5:24 AM CST	Special Marine Warning	LIX		96 min
Jan 21, 6:08 AM CST	Severe Thunderstorm Warning	LIX	Jefferson, Orleans	37 min
Jan 21, 6:38 AM CST	Special Marine Warning	LIX		37 min
Jan 21, 10:58 AM CST	River Flood Warning	LIX	Saint Helena	33 hr
Jan 21, 11:03 AM CST	River Flood Warning	LIX	Saint Tammany	13 days
Jan 21, 3:44 PM CST	Gale Warning	LIX		41 hr
Jan 21, 4:33 PM CST	Special Weather Statement	LIX	Orleans	42 min
Jan 21, 4:51 PM CST	Special Marine Warning	LIX		24 min
Jan 21, 4:54 PM CST	Special Weather Statement	LIX	Saint John the Baptist	36 min
Jan 21, 4:56 PM CST	Severe Thunderstorm Warning	LIX	Saint Charles	19 min
Jan 21, 5:02 PM CST	Tornado Warning	LIX	Orleans	13 min
Jan 21, 5:11 PM CST	Tornado Warning	LIX	Saint Charles	7 min
Jan 21, 5:16 PM CST	Severe Thunderstorm Warning	LIX	Saint Tammany	29 min
Jan 21, 5:20 PM CST	Special Marine Warning	LIX		40 min
Jan 21, 5:42 PM CST	Special Marine Warning	LIX		33 min
Jan 21, 5:47 PM CST	Severe Thunderstorm Warning	LIX	Pointe Coupee, West Feliciana	28 min
Jan 21, 5:52 PM CST	Special Marine Warning	LIX		38 min
Jan 20, 10:53 PM CST	Dense Fog Advisory	LIX		4 hr
Jan 21, 12:12 AM CST	Severe Thunderstorm Warning	LIX	Wilkinson	33 min
Jan 21, 12:26 AM CST	Tornado Warning	LIX	Amite, Wilkinson	14 min
Jan 21, 12:51 AM CST	Special Weather Statement	LIX	Wilkinson	39 min
Jan 21, 1:14 AM CST	Tornado Warning	LIX	Wilkinson	31 min
Jan 21, 1:29 AM CST	Severe Thunderstorm Warning	LIX	Wilkinson	31 min
Jan 21, 1:48 AM CST	Special Weather Statement	LIX	Amite	27 min
Jan 21, 4:43 AM CST	Special Weather Statement	LIX	Pearl River	62 min
Jan 21, 6:00 AM CST	Special Weather Statement	LIX	Hancock, Harrison	30 min
Jan 21, 8:59 AM CST	Special Weather Statement	LIX	Jackson	31 min
Jan 21, 5:51 PM CST	Special Weather Statement	LIX	Hancock	39 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 2017 Severe Thunderstorm Warnings in Mississippi, 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.