Alert archive / Washington / Mesoscale Discussions in 2009

Mesoscale Discussion 1539

July 12, 2009Benewah County, Bonner County, Kootenai County, Idaho; 5 counties in Washington

The Storm Prediction Center issued this mesoscale discussion at Jul 12, 2009, 10:55 PM PDT for Benewah County, Bonner County, Kootenai County, Idaho; 5 counties in Washington. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
Jul 12, 2009, 10:55 PM PDT (05:55 UTC)
Expired
Jul 13, 2009, 12:00 AM PDT
In force
65 min
Issued by
the Storm Prediction Center

Counties Benewah County, ID, Bonner County, ID, Kootenai County, ID, Lincoln County, WA, Pend Oreille County, WA, Spokane County, WA, Stevens County, WA, Whitman County, WA

The radar

The Spokane radar (KOTX), 22 km from the middle of the area, began a volume at 05:55 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 00:00Z, 5.9 hours before the alert went out and 72 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 00:00Z on 2009-07-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 191 joules per kilogram.LCLLFCEL10008507005003002001001 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 00:00Z on 2009-07-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 63 square meters per square second.19395878Sfc1 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
191 J/kg
Mixed-layer CIN
-11 J/kg
Mixed-layer LCL
2984 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
63 m²/s²
0-3 km storm-relative helicity
147 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 12, 8:48 PM PDTSevere Thunderstorm WatchSPCBenewah, Bonner, Boundary, Kootenai, Latah, Nez Perce4 hr

Nearby

Mesoscale Discussions in Washington, 2009Mesoscale Discussions in Idaho, 2009Every mesoscale discussion in 2009

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.