Alert archive / Colorado / Winter Storm Warnings in 2017

Winter Storm Warning 18, NWS Grand Junction, CO

December 24, 20179 counties in Colorado

NWS Grand Junction, CO issued this winter storm warning at Dec 24, 2017, 4:28 AM MST for 9 counties in Colorado. It took effect at Dec 24, 2017, 6:00 PM MST. It was in force for 24 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Dec 24, 2017, 4:28 AM MST (11:28 UTC)
In effect from
Dec 24, 2017, 6:00 PM MST
Expired
Dec 25, 2017, 6:00 PM MST
In force
24 hr
Issued by
NWS Grand Junction, CO

Counties Delta County, CO, Eagle County, CO, Garfield County, CO, Gunnison County, CO, Moffat County, CO, Montrose County, CO, Pitkin County, CO, Rio Blanco County, CO, Routt County, CO

The radar

The Grand Junction radar (KGJX), 74 km from the middle of the area, began a volume at 11:25 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

Denver, CO (KDEN), launched 00:00Z, 11.5 hours before the alert went out and 373 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, Denver, CO at 00:00Z on 2017-12-24Temperature 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 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 00:00Z on 2017-12-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 236 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
1673 m above ground
0-6 km bulk shear
95 kt
0-1 km storm-relative helicity
236 m²/s²
0-3 km storm-relative helicity
380 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 warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Grand Junction, CO wrote its last area forecast discussion before this winter storm warning went out at Dec 24, 3:37 AM MST, 51 minutes earlier.

Area forecast discussion, Dec 24, 3:37 AM MST, 51 minutes before
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Hazardous weather outlook, Dec 24, 3:09 AM MST, 1 hour 19 minutes before
Hazardous Weather Outlook
National Weather Service GRAND JUNCTION CO
309 AM MST Sun Dec 24 2017

COZ001>014-017>023-UTZ022>025-027>029-251015-
Lower Yampa River Basin-Central Yampa River Basin-
Roan and Tavaputs Plateaus-Elkhead and Park Mountains-
Upper Yampa River Basin-Grand Valley-Debeque to Silt Corridor-
Central Colorado River Basin-Grand and Battlement Mesas-
Gore and Elk Mountains/Central Mountain Valleys-
Central Gunnison and Uncompahgre River Basin-
West Elk and Sawatch Mountains-Flat Tops-
Upper Gunnison River Valley-Uncompahgre Plateau and Dallas Divide-
Northwest San Juan Mountains-Southwest San Juan Mountains-
Paradox Valley/Lower Dolores River-
Four Corners/Upper Dolores River-Animas River Basin-
San Juan River Basin-Southeast Utah-Eastern Uinta Mountains-
Eastern Uinta Basin-Tavaputs Plateau-Arches/Grand Flat-
La Sal and Abajo Mountains-Canyonlands/Natural Bridges-
309 AM MST Sun Dec 24 2017

This hazardous weather outlook is for eastern Utah and western
Colorado.

.DAY ONE...Today and Tonight

Snowfall is expected to decrease throughout today with an inch or
two additional snow accumulation over the northern and central
Colorado mountains. Windy conditions will continue producing local
blowing snow over higher exposed areas.

Tonight snowfall will increase again over the northern and central
Colorado mountains, where a Winter Storm Warning has been issued.
Northwest winds of 25 to 35 mph will also cause areas of blowing
and drifting snow.

.DAYS TWO THROUGH SEVEN...Christmas Day (Monday) through Saturday

Snowfall will continue Christmas Day over the northern and
central Colorado mountains, the higher plateaus and the central
and upper Colorado River valleys. Some lower elevation areas of
northwest and west-central Colorado, and the eastern Uinta
Mountains in northeast Utah will also receive occasional light
snow. Gust northwest winds will also produce areas of blowing and
drifting snow, especially over higher exposed area and high
mountain passes.

Another round of snow is possible Wednesday night and Thursday
for the mountains of western Colorado from about I-70 northward.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed.

In the hours before

Local storm report, Dec 23, 10:33 PM MST, 5 hours 55 minutes before
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The office that day

Everything else NWS Grand Junction, CO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 24, 1:26 PM MSTWinter Weather AdvisoryGJTEagle, Garfield, Gunnison, Moffat, Montrose, Pitkin and 2 more20 hr

Nearby

Winter Storm Warnings in Colorado, 2017Every winter storm warning in 2017

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.