Alert archive / Colorado / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 4, NWS Grand Junction, CO

May 9, 2017La Plata County, Colorado

NWS Grand Junction, CO issued this severe thunderstorm warning at May 9, 2017, 1:24 PM MDT for La Plata County, Colorado. It was in force for 36 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 9, 2017, 1:24 PM MDT (19:24 UTC)
Expired: May 9, 2017, 2:00 PM MDT
In force: 36 min
Issued by: NWS Grand Junction, CO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 70.0 mph

County La Plata County, CO

The radar

The Grand Junction radar (KGJX), 200 km from the middle of the area, began a volume at 19:27 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

Albuquerq/Krtlnd, NM (KABQ), launched 12:00Z, 7.4 hours before the alert went out and 273 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: 566 J/kg
Mixed-layer CIN: -80 J/kg
Mixed-layer LCL: 1602 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 139 m²/s²
0-3 km storm-relative helicity: 166 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.2

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 Grand Junction, CO wrote its last area forecast discussion before this severe thunderstorm warning went out at May 9, 11:49 AM MDT, 1 hour 35 minutes earlier.

Area forecast discussion, May 9, 11:49 AM MDT, 1 hour 35 minutes before

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Hazardous weather outlook, May 9, 9:28 AM MDT, 3 hours 56 minutes before

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In the hours before

Special weather statement, May 9, 11:45 AM MDT, 1 hour 39 minutes before

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Local storm report, May 9, 11:55 AM MDT, 1 hour 29 minutes before

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Local storm report, May 9, 12:10 PM MDT, 1 hour 14 minutes before

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Special weather statement, May 9, 12:11 PM MDT, 1 hour 13 minutes before

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Local storm report, May 9, 12:24 PM MDT, 1 hour before

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Special weather statement, May 9, 1:20 PM MDT, 4 minutes before

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The office that day

Everything else NWS Grand Junction, CO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 9, 7:38 AM MDT	Special Weather Statement	GJT	Montezuma	37 min
May 9, 8:20 AM MDT	Severe Thunderstorm Warning	GJT	Dolores, Montezuma	25 min
May 9, 11:45 AM MDT	Special Weather Statement	GJT	La Plata	45 min
May 9, 12:11 PM MDT	Special Weather Statement	GJT	San Juan	49 min
May 9, 1:20 PM MDT	Special Weather Statement	GJT	Rio Blanco	40 min
May 9, 1:26 PM MDT	Special Weather Statement	GJT	Pitkin	49 min
May 9, 2:33 PM MDT	Special Weather Statement	GJT	Routt	42 min
May 9, 2:17 PM MDT	Special Weather Statement	GJT	San Juan	43 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2017 Every severe thunderstorm warning in 2017

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.