Alert archive / Utah / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 1, NWS Salt Lake City, UT

April 28, 1999Box Elder County, Tooele County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Apr 28, 1999, 2:57 PM MDT for Box Elder County, Tooele County, Utah. It was in force for 33 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: Apr 28, 1999, 2:57 PM MDT (20:57 UTC)
Expired: Apr 28, 1999, 3:30 PM MDT
In force: 33 min
Issued by: NWS Salt Lake City, UT
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Box Elder County, UT, Tooele County, UT

The radar

The Salt Lake City radar (KMTX), 63 km from the middle of the area, began a volume at 20:59 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

Salt Lake City I, UT (KSLC), launched 12:00Z, 9.0 hours before the alert went out and 104 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: 1291 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 138 m²/s²
0-3 km storm-relative helicity: 228 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 Salt Lake City, UT wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 28, 10:00 AM MDT, 4 hours 57 minutes earlier.

Area forecast discussion, Apr 28, 10:00 AM MDT, 4 hours 57 minutes before

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The office that day

Everything else NWS Salt Lake City, UT issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 28, 3:56 PM MDT	Severe Thunderstorm Warning	SLC	Cache, Rich	34 min

Nearby

Severe Thunderstorm Warnings in Utah, 1999 Every severe thunderstorm warning in 1999

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.