Alert archive / Montana / Winter Storm Warnings in 2017

Winter Storm Warning 17, NWS Billings, MT

December 27, 201712 counties in Montana

NWS Billings, MT issued this winter storm warning at Dec 27, 2017, 4:04 AM MST for 12 counties in Montana. It took effect at Dec 27, 2017, 6:00 PM MST. It was in force for 70 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 27, 2017, 4:04 AM MST (11:04 UTC)
In effect from: Dec 27, 2017, 6:00 PM MST
Expired: Dec 30, 2017, 3:38 PM MST
In force: 70 hr
Issued by: NWS Billings, MT

Counties Big Horn County, MT, Carbon County, MT, Custer County, MT, Golden Valley County, MT, Musselshell County, MT, Park County, MT, Powder River County, MT, Rosebud County, MT, Stillwater County, MT, Sweet Grass County, MT, Treasure County, MT, Wheatland County, MT

The radar

The Billings radar (KBLX), 29 km from the middle of the area, began a volume at 11:05 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

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 11.1 hours before the alert went out and 284 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1207 m above ground
0-6 km bulk shear: 77 kt
0-1 km storm-relative helicity: 77 m²/s²
0-3 km storm-relative helicity: 159 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 Billings, MT wrote its last area forecast discussion before this winter storm warning went out at Dec 27, 3:39 AM MST, 25 minutes earlier.

Area forecast discussion, Dec 27, 3:39 AM MST, 25 minutes before

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Hazardous weather outlook, Dec 26, 6:02 PM MST, 10 hours 2 minutes before

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In the hours before

Special weather statement, Dec 27, 12:56 AM MST, 3 hours 8 minutes before

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The office that day

Everything else NWS Billings, MT issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 27, 12:56 AM MST	Special Weather Statement	BYZ	Sweet Grass	4 hr
Dec 27, 4:04 AM MST	Winter Storm Watch	BYZ	Big Horn, Carbon, Custer, Golden Valley, Musselshell, Park and 6 more	24 hr

Nearby

Winter Storm Warnings in Montana, 2017 Winter Storm Warnings in Wyoming, 2017 Every 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.