Alert archive / Oklahoma / Mesoscale Discussions in 2020
Mesoscale Discussion 607
The Storm Prediction Center issued this mesoscale discussion at May 15, 2020, 6:59 PM CDT for 11 counties in Oklahoma; 10 counties in Texas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 15, 2020, 6:59 PM CDT (23:59 UTC)
- Expired
- May 15, 2020, 9:00 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 21 counties
Bryan County, OK, Carter County, OK, Comanche County, OK, Cotton County, OK, Jefferson County, OK, Johnston County, OK, Love County, OK, Marshall County, OK, Murray County, OK, Stephens County, OK, Tillman County, OK, Archer County, TX, Baylor County, TX, Clay County, TX, Cooke County, TX, Grayson County, TX, Hardeman County, TX, Knox County, TX, Montague County, TX, Wichita County, TX, Wilbarger County, TX
The radar
The Altus AFB radar (KFDR), 69 km from the middle of the area, began a volume at 00:01 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Norman, OK (KOUN), launched 12:00Z, 12.0 hours before the alert went out and 153 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
- 1862 J/kg
- Mixed-layer CIN
- -241 J/kg
- Mixed-layer LCL
- 909 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 292 m²/s²
- 0-3 km storm-relative helicity
- 249 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted.
929
ACUS11 KWNS 160000
SWOMCD
SPC MCD 152359
OKZ000-TXZ000-160200-
Mesoscale Discussion 0607
NWS Storm Prediction Center Norman OK
0659 PM CDT Fri May 15 2020
Areas affected...North Texas...Southern Oklahoma
Concerning...Severe Thunderstorm Watch 186...
Valid 152359Z - 160200Z
The severe weather threat for Severe Thunderstorm Watch 186
continues.
SUMMARY...A severe threat will continue for several more hours
across WW 186 from southern Oklahoma into north Texas. Large hail
and wind damage will be the main threats.
DISCUSSION...The latest surface analysis shows a 1001 mb low in
northwest Texas with backed easterly surface winds across much of
north Texas and southern Oklahoma. An axis of low-level moisture
extends westward from northeast Texas into northwest Texas along the
Red River, where surface dewpoints are in the lower 70s F. This is
contributing to strong instability with the RAP estimating MLCAPE
around 3500 J/kg. In addition, the Frederick WSR-88D VWP shows 0-6
km near 45 kt with strong directional shear in the lowest 2 Km AGL.
This wind profile will be favorable for multicell line segments
although isolated supercells will also be possible. As cells
continue to congeal, a mult-segmented line segment with embedded
severe storms may organize and move eastward across north Texas over
the next few hours. The greatest potential would along the outflow
boundary where surface-based instability is present. Wind damage
will be possible along the leading edge of the more organized part
of the line segment. Isolated large hail will also be possible with
the more intense cores.
..Broyles.. 05/15/2020
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FWD...OUN...
LAT...LON 34269979 33649979 33509957 33559737 33519619 33839603
34359637 34719796 34749902 34459960 34269979SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 14, 10:04 PM CDT | Mesoscale Discussion | SPC | Alfalfa, Dewey, Ellis, Major, Woods, Woodward | 116 min |
| May 15, 11:04 AM CDT | Mesoscale Discussion | SPC | Haskell, Hughes, Latimer, LeFlore, McIntosh, Okfuskee and 4 more | 86 min |
| May 15, 1:08 PM CDT | Mesoscale Discussion | SPC | Atoka, Bryan, Caddo, Carter, Choctaw, Coal and 22 more | 2 hr |
| May 15, 1:39 PM CDT | Severe Thunderstorm Watch | SPC | Atoka, Beckham, Bryan, Caddo, Carter, Choctaw and 25 more | 8 hr |
| May 15, 3:36 PM CDT | Mesoscale Discussion | SPC | Atoka, Bryan, Caddo, Carter, Choctaw, Coal and 17 more | 84 min |
| May 15, 2:30 PM CDT | Mesoscale Discussion | SPC | Andrews, Borden, Brewster, Brown, Callahan, Childress and 54 more | 2 hr |
| May 15, 2:55 PM CDT | Severe Thunderstorm Watch | SPC | Andrews, Bandera, Borden, Brewster, Brown, Callahan and 66 more | 7 hr |
| May 15, 5:29 PM CDT | Mesoscale Discussion | SPC | Archer, Baylor, Brown, Callahan, Clay, Coke and 37 more | 2 hr |
Nearby
Mesoscale Discussions in Oklahoma, 2020Mesoscale Discussions in Texas, 2020Every mesoscale discussion in 2020
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.