Alert archive / Montana / Special Weather Statements in 2021

Special Weather Statement, NWS Missoula, MT

December 16, 2021Flathead County, Montana

NWS Missoula, MT issued this special weather statement at Dec 16, 2021, 1:12 PM MST for Flathead County, Montana. It was in force for 48 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Dec 16, 2021, 1:12 PM MST (20:12 UTC)
Expired
Dec 16, 2021, 2:00 PM MST
In force
48 min
Issued by
NWS Missoula, MT
Hail
0.00 in
Wind
30

County Flathead County, MT

The radar

The Missoula radar (KMSX), 152 km from the middle of the area, began a volume at 20:15 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

Spokane, WA (KOTX), launched 12:00Z, 8.2 hours before the alert went out and 170 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, Spokane, WA at 12:00Z on 2021-12-16Temperature 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, Spokane, WA at 12:00Z on 2021-12-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 78 square meters per square second.1939Sfc1 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
509 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
78 m²/s²
0-3 km storm-relative helicity
119 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

618 
WWUS85 KMSO 162012
SPSMSO

Special Weather Statement
National Weather Service Missoula MT
112 PM MST Thu Dec 16 2021
 
MTZ001>003-162100-
Flathead/Mission Valleys MT-West Glacier Region MT-
Kootenai/Cabinet Region MT-
112 PM MST Thu Dec 16 2021

...An intense snow shower will impact portions of east central
Lincoln and central Flathead Counties through 200 PM MST...

At 111 PM MST, trained weather spotters reported an intense snow 
shower over Columbia Falls and Hungry Horse, moving east at 5 mph.

HAZARD...Visibility one-half mile or less.

SOURCE...Trained weather spotters.

IMPACT...Low visibility could result in dangerous driving 
         conditions.

Locations impacted include...
Whitefish, Columbia Falls, Martin City, Coram, Lupfer, Pinnacle,
Essex, Hungry Horse, La Salle and Nyack.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4835 11506 4853 11455 4847 11353 4824 11360
TIME...MOT...LOC 2011Z 276DEG 9KT 4835 11417 

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...<30 MPH

$$

Nearby

Special Weather Statements in Montana, 2021Every special weather statement 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.