Alert archive / Nebraska / Tornado Watches in 1999

Tornado Watch 232

May 9, 199925 counties in Nebraska; 11 counties in South Dakota

The Storm Prediction Center issued this tornado watch at May 9, 1999, 3:30 PM MDT for 25 counties in Nebraska; 11 counties in South Dakota. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
May 9, 1999, 3:30 PM MDT (21:30 UTC)
Expired
May 9, 1999, 9:00 PM MDT
In force
6 hr
Issued by
the Storm Prediction Center
All 36 counties

Arthur County, NE, Blaine County, NE, Box Butte County, NE, Boyd County, NE, Brown County, NE, Cherry County, NE, Cheyenne County, NE, Dawes County, NE, Deuel County, NE, Garden County, NE, Garfield County, NE, Grant County, NE, Holt County, NE, Hooker County, NE, Keith County, NE, Keya Paha County, NE, Logan County, NE, Loup County, NE, McPherson County, NE, Morrill County, NE, Rock County, NE, Sheridan County, NE, Thomas County, NE, Valley County, NE, Wheeler County, NE, Aurora County, SD, Bennett County, SD, Brule County, SD, Charles Mix County, SD, Davison County, SD, Douglas County, SD, Gregory County, SD, Mellette County, SD, Oglala Lakota County, SD, Todd County, SD, Tripp County, SD

The radar

The North Platte radar (KLNX), 95 km from the middle of the area, began a volume at 21:31 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.

Warnings issued inside it

12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 9, 6:00 PM MDTSevere Thunderstorm WarningUNRBennett50 min
May 9, 6:25 PM MDTSevere Thunderstorm WarningUNRTripp50 min
May 9, 6:32 PM MDTTornado WarningUNRTripp33 min
May 9, 6:39 PM MDTTornado WarningUNRMellette31 min
May 9, 6:47 PM MDTSevere Thunderstorm WarningUNRMellette, Todd63 min
May 9, 6:55 PM MDTTornado WarningUNRMellette, Todd50 min
May 9, 7:19 PM MDTTornado WarningUNRMellette61 min
May 9, 7:38 PM MDTSevere Thunderstorm WarningUNRTripp47 min
May 9, 7:49 PM MDTTornado WarningUNRTodd46 min
May 9, 8:31 PM MDTTornado WarningUNRTodd34 min
May 9, 8:45 PM MDTSevere Thunderstorm WarningLBFMcPherson60 min
May 9, 8:56 PM MDTFlash Flood WarningUNRMellette, Todd4 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 9.5 hours before the alert went out and 328 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-pSkew-T log-p diagram, Aberdeen, SD at 12:00Z on 1999-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 12:00Z on 1999-05-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 46 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
890 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
46 m²/s²
0-3 km storm-relative helicity
302 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.

Nearby

Tornado Watches in Nebraska, 1999Tornado Watches in South Dakota, 1999Every tornado watch 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.