Alert archive / Idaho / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 19, NWS Boise, ID

August 11, 20154 counties in Idaho

NWS Boise, ID issued this severe thunderstorm warning at Aug 11, 2015, 5:17 PM MDT for 4 counties in Idaho. It was in force for 43 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: Aug 11, 2015, 5:17 PM MDT (23:17 UTC)
Expired: Aug 11, 2015, 6:00 PM MDT
In force: 43 min
Issued by: NWS Boise, ID
Area: Storm-based polygon

Counties Ada County, ID, Canyon County, ID, Elmore County, ID, Owyhee County, ID

The radar

The Boise radar (KCBX), 27 km from the middle of the area, began a volume at 23:18 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

Boise Airport, ID (KBOI), launched 12:00Z, 11.3 hours before the alert went out and 36 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: 8 J/kg
Mixed-layer CIN: -593 J/kg
Mixed-layer LCL: 2789 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 110 m²/s²
0-3 km storm-relative helicity: 235 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 severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Boise, ID wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 11, 2:51 PM MDT, 2 hours 26 minutes earlier.

Area forecast discussion, Aug 11, 2:51 PM MDT, 2 hours 26 minutes before

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In the hours before

Special weather statement, Aug 11, 3:13 PM MDT, 2 hours 4 minutes before

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Special weather statement, Aug 11, 4:11 PM MDT, 1 hour 6 minutes before

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Local storm report, Aug 11, 4:38 PM MDT, 39 minutes before

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Special weather statement, Aug 11, 4:38 PM MDT, 39 minutes before

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Special weather statement, Aug 11, 5:05 PM MDT, 12 minutes before

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Local storm report, Aug 11, 5:17 PM MDT, 0 minutes before

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The office that day

Everything else NWS Boise, ID issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 11, 8:29 AM MDT	Fire Weather Watch	BOI	Ada, Adams, Boise, Camas, Canyon, Elmore and 8 more	6 hr
Aug 11, 2:38 PM MDT	Red Flag Warning	BOI	Ada, Boise, Camas, Canyon, Elmore, Gem and 6 more	12 hr
Aug 11, 3:13 PM MDT	Special Weather Statement	BOI	Twin Falls	62 min
Aug 11, 4:11 PM MDT	Special Weather Statement	BOI	Jerome, Twin Falls	49 min
Aug 11, 4:38 PM MDT	Special Weather Statement	BOI	Gooding	52 min
Aug 11, 5:05 PM MDT	Special Weather Statement	BOI	Ada	40 min
Aug 11, 5:58 PM MDT	Severe Thunderstorm Warning	BOI	Ada, Canyon, Elmore	24 min

Nearby

Severe Thunderstorm Warnings in Idaho, 2015 Every severe thunderstorm warning in 2015

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.