Alert archive / Oklahoma / Mesoscale Discussions in 2021
Mesoscale Discussion 2043
The Storm Prediction Center issued this mesoscale discussion at Dec 17, 2021, 6:56 PM CST for 15 counties in Oklahoma; Cooke County, Texas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 17, 2021, 6:56 PM CST (00:56 UTC)
- Expired
- Dec 17, 2021, 9:00 PM CST
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
Counties Atoka County, OK, Carter County, OK, Cherokee County, OK, Coal County, OK, Haskell County, OK, Hughes County, OK, Johnston County, OK, Latimer County, OK, Love County, OK, Marshall County, OK, McIntosh County, OK, Murray County, OK, Muskogee County, OK, Pittsburg County, OK, Pontotoc County, OK, Cooke County, TX
The radar
The Norman radar (KTLX), 109 km from the middle of the area, began a volume at 00:59 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
Fort Worth, TX (KFWD), launched 00:00Z, 0.9 hours before the alert went out and 218 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
- 907 J/kg
- Mixed-layer CIN
- -61 J/kg
- Mixed-layer LCL
- 1218 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 138 m²/s²
- 0-3 km storm-relative helicity
- 205 m²/s²
- Significant tornado parameter
- 0.5
- Supercell composite
- 2.4
The text
As transmitted.
024 ACUS11 KWNS 180056 SWOMCD SPC MCD 180056 OKZ000-TXZ000-180300- Mesoscale Discussion 2043 NWS Storm Prediction Center Norman OK 0656 PM CST Fri Dec 17 2021 Areas affected...North-central TX to Eastern OK Concerning...Severe potential...Watch unlikely Valid 180056Z - 180300Z Probability of Watch Issuance...20 percent SUMMARY...Isolated wind/hail may be noted with the strongest updrafts this evening. Severe thunderstorm watch is not currently anticipated. DISCUSSION...Weak large-scale height falls are noted across the southern Plains this evening. Resultant surface pattern reflects this nebulous forcing with only a minor wave currently noted ahead of the front over northwest TX. A weak surface low will become more evident later this evening as it drifts northeast into OK. This should allow the cold front to surge south deeper into TX where it will be the focus for additional convection later tonight. Until then, pre frontal convection has been oriented from south-central OK into northeast OK for some time, and this corridor may not move appreciably over the next several hours due to weak low-level convergence and veered deeper flow. Latest radar data suggests marginally severe hail/wind continue to be noted with the strongest surface-based updrafts. With time this activity should be shunted southeast as the cold front begins to surge deeper into the southern Plains. ..Darrow/Hart.. 12/18/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TSA...FWD...OUN... LAT...LON 33979804 35399586 35969493 35059460 33579707 33979804
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 18, 1:17 AM CST | Mesoscale Discussion | SPC | Anderson, Bastrop, Bell, Bexar, Blanco, Bosque and 37 more | 118 min |
| Dec 18, 9:02 AM CST | Mesoscale Discussion | SPC | Aransas, Austin, Bee, Brazoria, Brazos, Caldwell and 32 more | 118 min |
| Dec 18, 12:50 PM CST | Mesoscale Discussion | SPC | Jefferson, Newton, Orange | 115 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.