Alert archive / Oklahoma / Mesoscale Discussions in 2021

Mesoscale Discussion 104

February 16, 202125 counties in Oklahoma; 8 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Feb 16, 2021, 8:14 PM CST for 25 counties in Oklahoma; 8 counties in Texas. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Feb 16, 2021, 8:14 PM CST (02:14 UTC)
Expired
Feb 17, 2021, 12:15 AM CST
In force
4 hr
Issued by
the Storm Prediction Center
Concerning
Heavy snow
All 33 counties

Atoka County, OK, Bryan County, OK, Carter County, OK, Choctaw County, OK, Cleveland County, OK, Coal County, OK, Comanche County, OK, Cotton County, OK, Garvin County, OK, Grady County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Latimer County, OK, Love County, OK, Marshall County, OK, McClain County, OK, Murray County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Pushmataha County, OK, Seminole County, OK, Stephens County, OK, Tillman County, OK, Archer County, TX, Clay County, TX, Cooke County, TX, Grayson County, TX, Jack County, TX, Montague County, TX, Wichita County, TX, Wilbarger County, TX

The radar

The Norman radar (KTLX), 112 km from the middle of the area, began a volume at 02:13 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, 2.2 hours before the alert went out and 101 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.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 00:00Z on 2021-02-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Norman, OK at 00:00Z on 2021-02-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 223 square meters per square second.1939587897117136Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
707 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
223 m²/s²
0-3 km storm-relative helicity
263 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

559 
ACUS11 KWNS 170215
SWOMCD
SPC MCD 170214 
OKZ000-TXZ000-170615-

Mesoscale Discussion 0104
NWS Storm Prediction Center Norman OK
0814 PM CST Tue Feb 16 2021

Areas affected...Parts of southern Oklahoma into north-central Texas

Concerning...Heavy snow 

Valid 170214Z - 170615Z

SUMMARY...Heavy snow appears most likely for south-central into
parts of southeastern Oklahoma per latest radar trends. Heavy snow
bands may occur in parts of southwestern into north-central
Oklahoma, but uncertainty is higher in these areas.

DISCUSSION...Recent KFWS and KFDR radar imagery show an area of
moderate to heavy snow moving northeastward from north-central and
northwestern Texas into south-central Oklahoma. This activity is
expected to persist for the next several hours as 850 winds and warm
advection increase with time in conjunction with continued mid-level
ascent. Snowfall rates around 1 inch per hour are possible.

Elsewhere in central Oklahoma, areas of banded precipitation have
produced 1 inch per hour rates. Radar presentation has shown a more
nebulous precipitation structure from southwestern Oklahoma into
north-central Oklahoma over the past 1-2 hours. However, recent
development of banding roughly along the I-44 corridor suggests some
remaining potential for heavy snow to impact the OKC metro as the
activity shifts to the northeast.

..Wendt.. 02/17/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...TSA...FWD...OUN...

LAT...LON   33349741 33169797 33409873 33979961 34369958 34749890
            35269766 35399698 35449629 35389580 35069529 34469509
            33939539 33629605 33349741

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 16, 6:59 PM CSTMesoscale DiscussionSPCArmstrong, Briscoe, Carson, Castro, Childress, Collingsworth and 7 more4 hr
Feb 16, 9:41 PM CSTMesoscale DiscussionSPCBell, Brazos, Burleson, Burnet, Falls, Lampasas and 5 more4 hr
Feb 17, 1:55 AM CSTMesoscale DiscussionSPCAngelina, Austin, Bastrop, Brazos, Burleson, Colorado and 31 more6 hr
Feb 17, 7:38 AM CSTMesoscale DiscussionSPCJasper, Newton, Sabine4 hr
Feb 17, 9:15 AM CSTMesoscale DiscussionSPCBowie, Cass6 hr

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.