Alert archive / Idaho / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 10, NWS Pocatello, ID

May 20, 2018Blaine County, Cassia County, Minidoka County, Idaho

NWS Pocatello, ID issued this severe thunderstorm warning at May 20, 2018, 1:23 PM MDT for Blaine County, Cassia County, Minidoka County, Idaho. It was in force for 67 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: May 20, 2018, 1:23 PM MDT (19:23 UTC)
Expired: May 20, 2018, 2:30 PM MDT
In force: 67 min
Issued by: NWS Pocatello, ID
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Blaine County, ID, Cassia County, ID, Minidoka County, ID

The radar

The Pocatello radar (KSFX), 90 km from the middle of the area, began a volume at 19:25 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

Elko, NV (KLKN), launched 12:00Z, 7.4 hours before the alert went out and 223 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: 1261 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 79 m²/s²
0-3 km storm-relative helicity: 133 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 Pocatello, ID wrote its last area forecast discussion before this severe thunderstorm warning went out at May 20, 3:13 AM MDT, 10 hours 10 minutes earlier.

Area forecast discussion, May 20, 3:13 AM MDT, 10 hours 10 minutes before

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In the hours before

Special weather statement, May 20, 12:27 PM MDT, 56 minutes before

Special Weather Statement
National Weather Service Pocatello ID
1227 PM MDT SUN MAY 20 2018

IDZ018-032-201930-
Lost River/Pashimeroi ID-Sawtooth Mountains ID-
1227 PM MDT SUN MAY 20 2018

...LINE OF WEAK THUNDERSTORMS LIFTING NORTH THROUGH THE CHALLIS
AREA THROUGH 130 PM MDT...

At 1224 PM MDT, Doppler radar was tracking a line of thunderstorms
extending from Chilly Barton Flat to 21 miles east of Sunbeam
moving north at 20 mph.

brief moderate rain, small hail, and wind gusts to 30 mph are
possible with these storms as they move north toward Ellis through
130 PM MDT.

Locations impacted include...
Challis, Chilly Barton Flat, Clayton, Willow Creek Summit, Herd Lake,
Bayhorse Lake, Meadow Peak and Mt Borah.

LAT...LON 4451 11383 4449 11381 4447 11368 4401 11378
      4412 11442 4460 11451 4459 11448 4462 11445
TIME...MOT...LOC 1824Z 179DEG 17KT 4408 11388 4415 11433

Huston

Special weather statement, May 20, 12:31 PM MDT, 52 minutes before

Special Weather Statement
National Weather Service Pocatello ID
1231 PM MDT SUN MAY 20 2018

IDZ017-022-201930-
South Central Highlands ID-Eastern Magic Valley ID-
1231 PM MDT SUN MAY 20 2018

...A LINE OF WEAK THUNDERSTORMS SOUTH OF BURLEY MOVING NORTH THROUGH
130 PM MDT...

At 1229 PM MDT, Doppler radar was tracking a line of thunderstorms
extending from 10 miles south of Burley to near Oakley Reservoir,
moving north at 15 mph.

Brief moderate rain, small hail, and wind gusts to 30 mph are
possible with these storms as they move north through the Burley
area through 130 PM MDT.

Locations impacted include...
Burley, Rupert, Heyburn, Paul and Oakley.

LAT...LON 4288 11368 4226 11367 4206 11387 4247 11389
TIME...MOT...LOC 1829Z 195DEG 13KT 4239 11382 4217 11383

Huston

The office that day

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

Issued	Product	Office	Counties	Lasted
May 20, 12:27 PM MDT	Special Weather Statement	PIH	Custer	63 min
May 20, 12:31 PM MDT	Special Weather Statement	PIH	Cassia	59 min
May 20, 1:30 PM MDT	Severe Thunderstorm Warning	PIH	Blaine, Cassia, Power	60 min
May 20, 2:07 PM MDT	Severe Thunderstorm Warning	PIH	Blaine, Cassia, Minidoka	38 min
May 20, 2:26 PM MDT	Severe Thunderstorm Warning	PIH	Blaine, Cassia, Power	49 min
May 20, 2:35 PM MDT	Special Weather Statement	PIH	Lincoln	85 min
May 20, 3:01 PM MDT	Severe Thunderstorm Warning	PIH	Bingham, Blaine, Power	44 min
May 20, 3:28 PM MDT	Special Weather Statement	PIH	Butte	92 min
May 20, 3:40 PM MDT	Severe Thunderstorm Warning	PIH	Bingham, Blaine, Butte, Power	50 min
May 20, 4:23 PM MDT	Severe Thunderstorm Warning	PIH	Bingham, Bonneville	52 min
May 20, 4:34 PM MDT	Special Weather Statement	PIH	Bingham	41 min
May 20, 5:11 PM MDT	Special Weather Statement	PIH	Bingham	64 min
May 20, 5:19 PM MDT	Special Weather Statement	PIH	Bonneville	56 min
May 20, 5:50 PM MDT	Special Weather Statement	PIH	Madison	40 min

Nearby

Severe Thunderstorm Warnings in Idaho, 2018 Every severe thunderstorm 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.