Alert archive / Oklahoma / Mesoscale Discussions in 2021
Mesoscale Discussion 1847
The Storm Prediction Center issued this mesoscale discussion at Oct 13, 2021, 1:18 AM CDT for 13 counties in Oklahoma; 5 counties in Texas. It was in force for 87 min.
The area
The outline as issued.
The facts
- Issued
- Oct 13, 2021, 1:18 AM CDT (06:18 UTC)
- Expired
- Oct 13, 2021, 2:45 AM CDT
- In force
- 87 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 526
Counties Alfalfa County, OK, Beckham County, OK, Blaine County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Greer County, OK, Harmon County, OK, Major County, OK, Roger Mills County, OK, Washita County, OK, Woods County, OK, Woodward County, OK, Childress County, TX, Collingsworth County, TX, Donley County, TX, Hall County, TX, Wheeler County, TX
The radar
The Altus AFB radar (KFDR), 132 km from the middle of the area, began a volume at 06:18 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
Amarillo Airport, TX (KAMA), launched 00:00Z, 6.3 hours before the alert went out and 179 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
- 165 J/kg
- Mixed-layer CIN
- -69 J/kg
- Mixed-layer LCL
- 2910 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km storm-relative helicity
- 141 m²/s²
- 0-3 km storm-relative helicity
- 172 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.7
The text
As transmitted.
956
ACUS11 KWNS 130619
SWOMCD
SPC MCD 130618
OKZ000-TXZ000-130745-
Mesoscale Discussion 1847
NWS Storm Prediction Center Norman OK
0118 AM CDT Wed Oct 13 2021
Areas affected...Portions of the far eastern TX
Panhandle...northwest TX...and western OK
Concerning...Tornado Watch 526...
Valid 130618Z - 130745Z
The severe weather threat for Tornado Watch 526 continues.
SUMMARY...A broken line of storms capable of producing scattered
severe wind gusts, isolated large hail, and occasional tornadoes
will continue into western Oklahoma early this morning.
DISCUSSION...Strong to severe storms have mostly grown upscale into
a broken line across the far eastern TX Panhandle and northwestern
OK along and just ahead of a surface cold front. A rather moist
low-level airmass is present ahead of this activity, with surface
dewpoints generally in the upper 60s to around 70F. But, RAP
forecast soundings from across this area show a shallow near-surface
stable layer present in low levels, which is contributing to weak
convective inhibition per latest mesoanalysis estimates. Regardless,
recent radar data from KVNX show strong inbound velocities
associated with the segment of the line across far northwestern OK.
A measured severe wind gust to 60 mph was recorded earlier at the OK
Mesonet site in Buffalo, OK as the line moved through. Scattered
severe/damaging wind gusts will likely remain the primary severe
threat with the line, as MLCAPE of 1500-2000 J/kg and 50+ kt of
effective bulk shear will continue to support storm organization and
intensity.
Farther south across the far eastern TX Panhandle, a couple of
supercells are present in a broken line. Isolated large hail will be
possible with this activity in the short term in addition to severe
downdraft winds. Given the strength of the low-level flow (55+ kt in
the 0-1-km layer per recent KFDR VWP) and a very favorable, curving
hodograph in the boundary layer, occasional tornadoes may occur with
any supercells that can remain at least semi-discrete, as well as
with low-level circulations embedded within the QLCS.
..Gleason.. 10/13/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...OUN...LUB...AMA...
LAT...LON 34980089 35650008 36929936 36959791 36269808 35579848
35019901 34390005 34130103 34250128 34980089SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 12, 7:30 PM CDT | Mesoscale Discussion | SPC | Beaver, Beckham, Caddo, Comanche, Cotton, Custer and 10 more | 2 hr |
| Oct 12, 9:18 PM CDT | Mesoscale Discussion | SPC | Beaver, Beckham, Blaine, Caddo, Canadian, Comanche and 12 more | 117 min |
| Oct 12, 11:05 PM CDT | Tornado Watch | SPC | Alfalfa, Beaver, Beckham, Blaine, Caddo, Canadian and 19 more | 7 hr |
| Oct 13, 3:26 AM CDT | Mesoscale Discussion | SPC | Blaine, Caddo, Canadian, Garfield, Grant, Jackson and 6 more | 94 min |
| Oct 13, 5:16 AM CDT | Mesoscale Discussion | SPC | Cleveland, Creek, Grady, Lincoln, Logan, McClain and 9 more | 59 min |
| Oct 13, 7:34 AM CDT | Mesoscale Discussion | SPC | Cherokee, Craig, Delaware, Hughes, McIntosh, Mayes and 9 more | 116 min |
| Oct 13, 3:59 PM CDT | Mesoscale Discussion | SPC | Brown, Coleman, Collin, Comanche, Cooke, Denton and 9 more | 91 min |
Nearby
Mesoscale Discussions in Oklahoma, 2021Mesoscale Discussions in Texas, 2021Every mesoscale discussion 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.