Alert archive / Montana / Winter Weather Advisories in 2011

Winter Weather Advisory 39, NWS Missoula, MT

April 5, 20118 counties in Montana; Idaho County, Lemhi County, Idaho

NWS Missoula, MT issued this winter weather advisory at Apr 5, 2011, 2:13 PM MDT for 8 counties in Montana; Idaho County, Lemhi County, Idaho. It took effect at Apr 6, 2011, 6:00 AM MDT. It was in force for 56 hr.

The area

The counties it named.

The facts

Issued
Apr 5, 2011, 2:13 PM MDT (20:13 UTC)
In effect from
Apr 6, 2011, 6:00 AM MDT
Expired
Apr 8, 2011, 2:17 PM MDT
In force
56 hr
Issued by
NWS Missoula, MT

Counties Idaho County, ID, Lemhi County, ID, Deer Lodge County, MT, Granite County, MT, Mineral County, MT, Missoula County, MT, Powell County, MT, Ravalli County, MT, Sanders County, MT, Silver Bow County, MT

The radar

The Missoula radar (KMSX), 72 km from the middle of the area, began a volume at 20:12 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 235 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 2011-04-05Temperature 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 2011-04-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 111 square meters per square second.1939587897117136156175Sfc1 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
958 m above ground
0-6 km bulk shear
81 kt
0-1 km storm-relative helicity
111 m²/s²
0-3 km storm-relative helicity
148 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 5, 3:55 AM MDTLake Wind AdvisoryMSOFlathead, Lake, Sanders16 hr
Apr 5, 3:55 AM MDTWind AdvisoryMSODeer Lodge, Granite, Lake, Missoula, Powell, Ravalli and 1 more16 hr

Nearby

Winter Weather Advisories in Montana, 2011Winter Weather Advisories in Idaho, 2011Every winter weather advisory in 2011

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.