Alert archive / Arkansas / Winter Storm Watches in 2020

Winter Storm Watch 4, NWS Tulsa, OK

December 12, 20204 counties in Arkansas

NWS Tulsa, OK issued this winter storm watch at Dec 12, 2020, 9:20 PM CST for 4 counties in Arkansas. It took effect at Dec 13, 2020, 6:00 AM CST. It was in force for .

The area

The counties it named.

The facts

Issued
Dec 12, 2020, 9:20 PM CST (03:20 UTC)
In effect from
Dec 13, 2020, 6:00 AM CST
Expired
Dec 13, 2020, 3:01 AM CST
In force
Issued by
NWS Tulsa, OK

Counties Benton County, AR, Carroll County, AR, Madison County, AR, Washington County, AR

The radar

The Western Arkansas radar (KSRX), 105 km from the middle of the area, began a volume at 03:25 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

Springfield, MO (KSGF), launched 00:00Z, 3.3 hours before the alert went out and 82 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, Springfield, MO at 00:00Z on 2020-12-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLLFCEL10008507005003002001001 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, Springfield, MO at 00:00Z on 2020-12-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 square meters per square second.1939587897117Sfc1 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
583 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
23 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this winter storm watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Tulsa, OK wrote its last area forecast discussion before this winter storm watch went out at Dec 12, 5:15 PM CST, 4 hours 5 minutes earlier.

Area forecast discussion, Dec 12, 5:15 PM CST, 4 hours 5 minutes before
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Hazardous weather outlook, Dec 12, 5:00 PM CST, 4 hours 20 minutes before
Hazardous Weather Outlook
National Weather Service Tulsa OK
500 PM CST Sat Dec 12 2020

ARZ001-002-010-011-019-020-029-OKZ049-053>076-131130-
Adair OK-Benton AR-Carroll AR-Cherokee OK-Choctaw OK-Craig OK-
Crawford AR-Creek OK-Delaware OK-Franklin AR-Haskell OK-Latimer OK-
Le Flore OK-Madison AR-Mayes OK-McIntosh OK-Muskogee OK-Nowata OK-
Okfuskee OK-Okmulgee OK-Osage OK-Ottawa OK-Pawnee OK-Pittsburg OK-
Pushmataha OK-Rogers OK-Sebastian AR-Sequoyah OK-Tulsa OK-Wagoner OK-
Washington OK-Washington AR-
500 PM CST Sat Dec 12 2020

This Outlook is for Northwest and West Central Arkansas as well as
much of Eastern Oklahoma.

...TRAVEL IMPACTS LIKELY ACROSS NORTHEAST OKLAHOMA AND NORTHWEST
ARKANSAS ON SUNDAY...

.DAY ONE...Tonight.

WINTER WEATHER.
	SNOW ACCUMULATION.
	RISK...Limited.
	AREA...Northeast Oklahoma, west of Highway 75, especially Osage
            and Pawnee counties.
    ONSET...After 3 AM.

	Additional Snow Accumulations Sunday.

DISCUSSION...
Areas of light snow will spread into northeast Oklahoma late
tonight with light snow accumulations likely west of Highway 75.
Snow coverage and intensity will increase during the day
Sunday. Road conditions are expected to deteriorate with time.

SPOTTER AND EMERGENCY MANAGEMENT ACTION STATEMENT...
Spotter Activation Not Expected.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.
SUNDAY...Winter Weather Potential.
MONDAY...No Hazards.
TUESDAY...Winter Weather Potential.
WEDNESDAY through FRIDAY...No Hazards.

EXTENDED DISCUSSION...
Widespread light to moderate snow will overspread much of
eastern Oklahoma and northwest Arkansas Sunday through Sunday
evening.  A corridor of moderate to heavy snow is likely to
develop from mid morning through Sunday afternoon, though the exact
location of the heavier snow remains uncertain. Temperatures are
likely to remain near or slightly above freezing where snow does
fall, and will be a limiting factor for accumulation. However,
snowfall intensity will be heavy enough at times to allow for
accumulation on grassy and elevated surfaces in the 1 to 4 inch
range with locally heavier amounts across northeast Oklahoma and
northwest Arkansas. Accumulation of snow on roads and bridges is
expected, especially in the heavier snow bands. Slick spots due to
slushy road conditions will impact travel, especially north of
Interstate 40. The high terrain areas of southeast Oklahoma could be
impacted as well.

Wet roadways and bridges from the melting snow are likely to freeze
as temperatures drop well below freezing Sunday night into Monday.
Thus, travel impacts are expected to linger into the morning commute
on Monday.

Another storm system is expected to bring the potential for more
snow accumulation across northeast Oklahoma and northwest Arkansas
on Tuesday and could impact travel north of Interstate 40.

weather.gov/tulsa contains additional information.

The office that day

Everything else NWS Tulsa, OK issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 13, 3:01 AM CSTWinter Storm WarningTSAAdair, Cherokee, Creek, Delaware, Mayes, Muskogee and 5 more17 hr

Nearby

Winter Storm Watches in Arkansas, 2020Every winter storm watch 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.