Alert archive / Minnesota / Tornado Warnings in 1987

Tornado Warning 6, NWS Grand Forks, ND

July 18, 1987Clearwater County, Minnesota

NWS Grand Forks, ND issued this tornado warning at Jul 18, 1987, 7:10 PM CDT for Clearwater County, Minnesota. It was in force for 30 min.

The area

The counties it named.

The facts

Issued
Jul 18, 1987, 7:10 PM CDT (00:10 UTC)
Expired
Jul 18, 1987, 7:40 PM CDT
In force
30 min
Issued by
NWS Grand Forks, ND
Area
Whole counties

County Clearwater County, MN

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

International Fa, MN (KINL), launched 00:00Z, 0.2 hours before the alert went out and 190 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, International Fa, MN at 00:00Z on 1987-07-19Temperature 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, International Fa, MN at 00:00Z on 1987-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 264 square meters per square second.1939Sfc1 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
605 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
264 m²/s²
0-3 km storm-relative helicity
319 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 tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Local storm report, Jul 18, 6:21 PM CDT, 49 minutes before
STORM REPORTS
NATIONAL WEATHER SERVICE FARGO ND
615 PM CDT SAT JUL 18 1987

TIME      EVENT
612PM     MAHNOMEN CTY MN S. O. REPORTED FUNNEL CLOUD AT NAYTAHWAUSH
          MN. LOCATED ON MAHNOMEN/CLEARWATER CTY LINE. FAR RADAR SHOWED
          VIP LVL 4 AT THAT LOCATION.

Nearby

Tornado Warnings in Minnesota, 1987Every tornado warning in 1987Tornadoes in 1987

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.