Alert archive / Idaho / Flash Flood Warnings in 2018

Flash Flood Warning 1, NWS Boise, ID

May 26, 2018Boise County, Idaho

NWS Boise, ID issued this flash flood warning at May 26, 2018, 2:31 PM MDT for Boise County, Idaho. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: May 26, 2018, 2:31 PM MDT (20:31 UTC)
Expired: May 26, 2018, 5:30 PM MDT
In force: 3 hr
Issued by: NWS Boise, ID
Area: Storm-based polygon
Flood severity: None

County Boise County, ID

The radar

The Boise radar (KCBX), 69 km from the middle of the area, began a volume at 20:31 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, 8.5 hours before the alert went out and 60 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: 2 J/kg
Mixed-layer CIN: -294 J/kg
Mixed-layer LCL: 1024 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: -18 m²/s²
0-3 km storm-relative helicity: 8 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 flash flood 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 flash flood warning went out at May 26, 2:11 PM MDT, 20 minutes earlier.

Area forecast discussion, May 26, 2:11 PM MDT, 20 minutes before

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In the hours before

Special weather statement, May 26, 2:05 PM MDT, 26 minutes before

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    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
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        The site you requested is temporarily down for maintenance or an unexpected outage.
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The office that day

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

Issued	Product	Office	Counties	Lasted
May 25, 6:01 PM MDT	Severe Thunderstorm Warning	BOI	Canyon, Owyhee	59 min
May 25, 6:34 PM MDT	Severe Thunderstorm Warning	BOI	Ada, Canyon, Owyhee	56 min
May 25, 7:00 PM MDT	Special Weather Statement	BOI	Adams	45 min
May 25, 7:00 PM MDT	Severe Thunderstorm Warning	BOI	Canyon, Owyhee	60 min
May 25, 7:29 PM MDT	Severe Thunderstorm Warning	BOI	Ada, Canyon, Owyhee	31 min
May 25, 7:44 PM MDT	Severe Thunderstorm Warning	BOI	Washington	61 min
May 25, 7:52 PM MDT	Special Weather Statement	BOI	Elmore	53 min
May 25, 8:00 PM MDT	Severe Thunderstorm Warning	BOI	Ada, Canyon, Gem, Owyhee, Payette	45 min
May 25, 8:05 PM MDT	Severe Thunderstorm Warning	BOI	Adams	40 min
May 25, 8:13 PM MDT	Severe Thunderstorm Warning	BOI	Boise, Gem, Valley, Washington	62 min
May 25, 8:41 PM MDT	Severe Thunderstorm Warning	BOI	Adams, Valley, Washington	64 min
May 25, 8:45 PM MDT	Special Weather Statement	BOI	Canyon	30 min
May 25, 8:51 PM MDT	Severe Thunderstorm Warning	BOI	Adams, Washington	54 min
May 25, 9:16 PM MDT	Special Weather Statement	BOI	Gem	29 min
May 25, 9:48 PM MDT	Severe Thunderstorm Warning	BOI	Adams	27 min
May 26, 2:05 PM MDT	Special Weather Statement	BOI	Boise	55 min
May 25, 6:38 PM MDT	Severe Thunderstorm Warning	BOI	Baker, Malheur	67 min

Nearby

Flash Flood Warnings in Idaho, 2018 Every flash flood warning in 2018

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.