Alert archive / Louisiana / Mesoscale Discussions in 2017
Mesoscale Discussion 404
The Storm Prediction Center issued this mesoscale discussion at Apr 2, 2017, 2:06 PM CDT for 7 parishes in Louisiana; Sabine County, Texas. It was in force for 54 min.
The area
The outline as issued.
The facts
- Issued
- Apr 2, 2017, 2:06 PM CDT (19:06 UTC)
- Expired
- Apr 2, 2017, 3:00 PM CDT
- In force
- 54 min
- Issued by
- the Storm Prediction Center
Counties Grant Parish, LA, LaSalle Parish, LA, Natchitoches Parish, LA, Rapides Parish, LA, Sabine Parish, LA, Vernon Parish, LA, Winn Parish, LA, Sabine County, TX
The radar
The Ft Polk radar (KPOE), 31 km from the middle of the area, began a volume at 19:04 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
Shreveport, LA (KBAD), launched 12:00Z, 7.1 hours before the alert went out and 137 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.
- Mixed-layer CAPE
- 25 J/kg
- Mixed-layer CIN
- -354 J/kg
- Mixed-layer LCL
- 1030 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km storm-relative helicity
- 141 m²/s²
- 0-3 km storm-relative helicity
- 206 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
384
ACUS11 KWNS 021907
SWOMCD
SPC MCD 021906
LAZ000-TXZ000-022000-
Mesoscale Discussion 0404
NWS Storm Prediction Center Norman OK
0206 PM CDT Sun Apr 02 2017
Areas affected...Portions of far east Texas into central LA
Concerning...Tornado Watch 110...
Valid 021906Z - 022000Z
The severe weather threat for Tornado Watch 110 continues.
SUMMARY...The risk for significant tornadoes is increasing across
Particularly Dangerous Situation Tornado Watch 110.
DISCUSSION...Echo tops in association with supercell clusters and
quasi-linear convective segments containing embedded supercells have
exhibited notable increasing trends per radar imagery. This activity
is intensifying within a warm advection plume preceding a midlevel
shortwave trough spreading across Texas. Pressure falls have been
increasing in magnitude within the open warm sector from parts of
the lower Sabine Valley eastward through central LA, south of a warm
front analyzed from south of Shreveport to north of Alexandria LA.
This suggests that increasing deep ascent will continue to encourage
convective sustenance/intensification. The VAD wind profile at POE
indicates a substantially curved hodograph in the lowest 3 km above
ground, with around 400 m2/s2 of 0-1-km SRH. Rotating updrafts will
remain likely as convection spreads eastward/east-northeastward
across the region. The risk for significant tornadoes is increasing,
along with damaging winds and severe hail.
..Cohen.. 04/02/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...JAN...LCH...SHV...
LAT...LON 30959406 31779396 32029347 32159279 31999237 31709188
31349178 31179208 30969289 30819345 30959406SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 2, 9:04 AM CDT | Mesoscale Discussion | SPC | Beauregard, Sabine, Vernon | 2 hr |
| Apr 2, 9:05 AM CDT | Mesoscale Discussion | SPC | Acadia, Ascension, East Baton Rouge, Iberville, Lafayette, Livingston and 5 more | 85 min |
| Apr 2, 10:39 AM CDT | Tornado Watch | SPC | Bienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 13 more | 5 hr |
| Apr 2, 12:22 PM CDT | Mesoscale Discussion | SPC | Sabine | 83 min |
| Apr 2, 12:49 PM CDT | Mesoscale Discussion | SPC | Avoyelles, Concordia, East Baton Rouge, East Carroll, East Feliciana, Franklin and 7 more | 116 min |
| Apr 2, 1:34 PM CDT | Tornado Watch | SPC | Acadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 28 more | 7 hr |
| Apr 2, 3:08 PM CDT | Mesoscale Discussion | SPC | Ascension, East Baton Rouge, East Feliciana, Livingston, Saint Charles, Saint Helena and 6 more | 3 hr |
| Apr 2, 3:13 PM CDT | Mesoscale Discussion | SPC | Allen, Avoyelles, Beauregard, Caldwell, Catahoula, Concordia and 13 more | 92 min |
| Apr 2, 4:52 PM CDT | Tornado Watch | SPC | Ascension, Concordia, East Baton Rouge, East Feliciana, Iberville, Livingston and 8 more | 9 hr |
| Apr 2, 5:54 PM CDT | Mesoscale Discussion | SPC | Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Catahoula and 7 more | 96 min |
| Apr 1, 7:20 PM CDT | Mesoscale Discussion | SPC | Val Verde | 85 min |
| Apr 1, 8:44 PM CDT | Mesoscale Discussion | SPC | Brown, Callahan, Coleman, Comanche, Concho, Eastland and 5 more | 61 min |
| Apr 1, 10:06 PM CDT | Mesoscale Discussion | SPC | Bandera, Bexar, Blanco, Comal, Edwards, Gillespie and 9 more | 114 min |
| Apr 1, 10:28 PM CDT | Tornado Watch | SPC | Bandera, Edwards, Gillespie, Kerr, Kimble, Kinney and 6 more | 8 hr |
| Apr 2, 2:53 AM CDT | Mesoscale Discussion | SPC | Bandera, Edwards, Gillespie, Kerr, Kimble, Kinney and 6 more | 82 min |
| Apr 2, 5:16 AM CDT | Mesoscale Discussion | SPC | Anderson, Angelina, Bandera, Bastrop, Bell, Bexar and 51 more | 119 min |
| Apr 2, 6:00 AM CDT | Tornado Watch | SPC | Anderson, Atascosa, Bandera, Bastrop, Bell, Bexar and 51 more | 7 hr |
| Apr 2, 9:44 AM CDT | Mesoscale Discussion | SPC | Austin, Bastrop, Brazos, Burleson, Caldwell, Cherokee and 19 more | 2 hr |
| Apr 2, 4:23 PM CDT | Mesoscale Discussion | SPC | Aransas, Brazoria, Calhoun, Cameron, Jackson, Kenedy and 5 more | 3 hr |
Nearby
Mesoscale Discussions in Louisiana, 2017Mesoscale Discussions in Texas, 2017Every mesoscale discussion 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; radar from the NEXRAD Level II archive.