Alert archive / Oklahoma / Mesoscale Discussions in 2021
Mesoscale Discussion 133
The Storm Prediction Center issued this mesoscale discussion at Feb 28, 2021, 1:47 AM CST for 14 counties in Oklahoma. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 28, 2021, 1:47 AM CST (07:47 UTC)
- Expired
- Feb 28, 2021, 4:15 AM CST
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 5%
Counties Cleveland County, OK, Creek County, OK, Lincoln County, OK, Mayes County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Pawnee County, OK, Payne County, OK, Pottawatomie County, OK, Rogers County, OK, Tulsa County, OK, Wagoner County, OK, Washington County, OK
The radar
The Tulsa radar (KINX), 85 km from the middle of the area, began a volume at 07:51 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
Norman, OK (KOUN), launched 00:00Z, 7.8 hours before the alert went out and 113 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
- -143 J/kg
- Mixed-layer LCL
- 538 m above ground
- 0-6 km bulk shear
- 74 kt
- 0-1 km storm-relative helicity
- 430 m²/s²
- 0-3 km storm-relative helicity
- 418 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.7
The text
As transmitted.
415
ACUS11 KWNS 280747
SWOMCD
SPC MCD 280747
OKZ000-281015-
Mesoscale Discussion 0133
NWS Storm Prediction Center Norman OK
0147 AM CST Sun Feb 28 2021
Areas affected...Arkansas
Concerning...Severe potential...Watch unlikely
Valid 280747Z - 281015Z
Probability of Watch Issuance...5 percent
SUMMARY...A storm or two may briefly produce marginal hail from
central into northeast Oklahoma.
DISCUSSION...Surface analysis shows a cold front moving across
northern OK, with showers now developing along it. While the
low-level air mass is moist, drying is occurring aloft with GPS
water-vapor values decreasing with time. Still, there may be
sufficient boundary-layer moisture to sustain brief thunderstorms
along the cold front over the next few hours. The better moisture
quality currently resides along and east of the I-44 corridor,
beneath ample southwesterly flow aloft elongating hodographs. The
favorable deep-layer shear as well as cold midlevel temperatures
will conditionally favor a strong cell or two, but any threat should
remain isolated, and likely short-lived.
..Jewell/Edwards.. 02/28/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...TSA...OUN...
LAT...LON 35179700 35149750 35339773 35679773 36689617 36809542
36669502 36279495 35679576 35179700SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 28, 9:59 AM CST | Mesoscale Discussion | SPC | Choctaw, McCurtain, Pushmataha | 91 min |
| Feb 28, 10:43 AM CST | Severe Thunderstorm Watch | SPC | Choctaw, LeFlore, McCurtain, Pushmataha | 7 hr |
| Feb 28, 5:28 PM CST | Mesoscale Discussion | SPC | McCurtain | 2 hr |
Nearby
Mesoscale Discussions in Oklahoma, 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.