Alert archive / Washington / Severe Thunderstorm Warnings in 2010

Severe Thunderstorm Warning 1, NWS Seattle, WA

December 8, 2010Snohomish County, Washington

NWS Seattle, WA issued this severe thunderstorm warning at Dec 8, 2010, 8:15 AM PST for Snohomish County, Washington. It was in force for 30 min. 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 8, 2010, 8:15 AM PST (16:15 UTC)
Expired
Dec 8, 2010, 8:45 AM PST
In force
30 min
Issued by
NWS Seattle, WA
Area
Storm-based polygon

County Snohomish County, WA

The radar

The Seattle radar (KATX), 60 km from the middle of the area, began a volume at 16:15 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, 4.3 hours before the alert went out and 399 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 2010-12-08Temperature 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 2010-12-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 275 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
1094 m above ground
0-6 km bulk shear
70 kt
0-1 km storm-relative helicity
275 m²/s²
0-3 km storm-relative helicity
391 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

Everything else NWS Seattle, WA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 7, 9:15 PM PSTRiver Flood AdvisorySEWMason14 hr
Dec 8, 1:14 AM PSTRiver Flood WarningSEWMason59 hr
Dec 8, 4:08 AM PSTWinter Storm WarningSEW56 hr
Dec 8, 4:08 AM PSTWinter Weather AdvisorySEW56 hr

Nearby

Severe Thunderstorm Warnings in Washington, 2010Every severe thunderstorm warning in 2010

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.