Alert archive / Washington / Frost Advisories in 2026

Frost Advisory 1, NWS Spokane, WA

April 23, 2026Asotin County, Garfield County, Washington; Nez Perce County, Idaho

NWS Spokane, WA issued this frost advisory at Apr 23, 2026, 1:05 PM PDT for Asotin County, Garfield County, Washington; Nez Perce County, Idaho. It took effect at Apr 24, 2026, 2:00 AM PDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued: Apr 23, 2026, 1:05 PM PDT (20:05 UTC)
In effect from: Apr 24, 2026, 2:00 AM PDT
Expired: Apr 24, 2026, 9:00 AM PDT
In force: 7 hr
Issued by: NWS Spokane, WA

Counties Nez Perce County, ID, Asotin County, WA, Garfield County, WA

The radar

The Pendleton radar (KPDT), 148 km from the middle of the area, began a volume at 20:09 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

Salem/Mcnary, OR (KSLE), launched 12:00Z, 8.1 hours before the alert went out and 479 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: 12 J/kg
Mixed-layer CIN: -8 J/kg
Mixed-layer LCL: 919 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: -8 m²/s²
0-3 km storm-relative helicity: 144 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 frost 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 frost advisory went out at Apr 23, 10:33 AM PDT, 2 hours 32 minutes earlier.

Area forecast discussion, Apr 23, 10:33 AM PDT, 2 hours 32 minutes before

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Nearby

Frost Advisories in Washington, 2026 Frost Advisories in Idaho, 2026 Every frost advisory in 2026

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.