Alert archive / Idaho / Mesoscale Discussions in 2020

Mesoscale Discussion 506

April 30, 202014 counties in Idaho; Baker County, Malheur County, Oregon

The Storm Prediction Center issued this mesoscale discussion at Apr 30, 2020, 11:36 AM MDT for 14 counties in Idaho; Baker County, Malheur County, Oregon. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Apr 30, 2020, 11:36 AM MDT (17:36 UTC)
Expired: Apr 30, 2020, 1:00 PM MDT
In force: 84 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Ada County, ID, Boise County, ID, Camas County, ID, Canyon County, ID, Custer County, ID, Elmore County, ID, Gem County, ID, Gooding County, ID, Jerome County, ID, Lincoln County, ID, Owyhee County, ID, Payette County, ID, Twin Falls County, ID, Washington County, ID, Baker County, OR, Malheur County, OR

The radar

The Boise radar (KCBX), 52 km from the middle of the area, began a volume at 17:36 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, 5.6 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1842 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: -72 m²/s²
0-3 km storm-relative helicity: 74 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 30, 2:58 PM MDT	Mesoscale Discussion	SPC	Ada, Bannock, Bear Lake, Bingham, Blaine, Boise and 20 more	92 min

Nearby

Mesoscale Discussions in Idaho, 2020 Mesoscale Discussions in Oregon, 2020 Every mesoscale discussion in 2020

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.