Alert archive / Idaho / Areal Flood Advisories in 2021

Areal Flood Advisory 6, NWS Spokane, WA

August 1, 2021Lewis County, Idaho

NWS Spokane, WA issued this areal flood advisory at Aug 1, 2021, 8:15 PM PDT for Lewis County, Idaho. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: Aug 1, 2021, 8:15 PM PDT (03:15 UTC)
Expired: Aug 1, 2021, 11:15 PM PDT
In force: 3 hr
Issued by: NWS Spokane, WA
Area: Storm-based polygon

County Lewis County, ID

The radar

The Spokane radar (KOTX), 185 km from the middle of the area, began a volume at 03:16 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, 3.3 hours before the alert went out and 163 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1384 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: -16 m²/s²
0-3 km storm-relative helicity: 23 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 areal flood advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Spokane, WA wrote its last area forecast discussion before this areal flood advisory went out at Aug 1, 4:00 PM PDT, 4 hours 15 minutes earlier.

Area forecast discussion, Aug 1, 4:00 PM PDT, 4 hours 15 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 2, 2:37 AM PDT	Excessive Heat Watch	OTX	Adams, Asotin, Chelan, Douglas, Ferry, Garfield and 7 more	12 hr
Aug 2, 2:46 PM PDT	Heat Advisory	OTX	Adams, Asotin, Chelan, Douglas, Ferry, Garfield and 7 more	56 hr
Aug 1, 6:23 PM PDT	Flash Flood Warning	OTX	Shoshone	3 hr

Nearby

Areal Flood Advisories in Idaho, 2021 Every areal flood advisory in 2021

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.