Alert archive / Minnesota / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 79, NWS Grand Forks, ND

August 11, 1987Lake of the Woods County, Roseau County, Minnesota

NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 11, 1987, 2:50 PM CDT for Lake of the Woods County, Roseau County, Minnesota. It was in force for 60 min.

The area

The counties it named.

The facts

Issued: Aug 11, 1987, 2:50 PM CDT (19:50 UTC)
Expired: Aug 11, 1987, 3:50 PM CDT
In force: 60 min
Issued by: NWS Grand Forks, ND
Area: Whole counties

Counties Lake of the Woods County, MN, Roseau 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 12:00Z, 7.8 hours before the alert went out and 153 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: 475 J/kg
Mixed-layer CIN: -165 J/kg
Mixed-layer LCL: 802 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 96 m²/s²
0-3 km storm-relative helicity: 107 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KINL 111954
SVRINL
MNC077-135-112050-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE INTERNATIONAL FALLS MN
250 PM CDT TUE AUG 11 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL 350 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES OF

NORTHWESTERN  MINNESOTA..LAKE OF THE WOODS AND THE EASTERN HALF OF
ROSEAU ..INCLUDING THE TOWNS OF WARROAD ROOSEVELT WILLIAMS AND
GRACETON.

AT 250 PM..RADAR INDICATED A SEVERE THUNDERSTORM 70 MILES NORTHEAST
OF GRAND FORKS NORTH DAKOTA MOVING TOWARD THE EAST AT ABOUT 30 MPH.

REMENBER SEVERE THUNDERSTORMS PRODUCE STRONG DAMAGING WINDS..LARGE
HAIL AND FREQUENT LIGHTING STRIKES. ALSO SEVERE THUNDERSTORMS CAN AND
OCCASIONALY DO PRODUCE A TORNADO WITH LITTLE OR NO ADVANCE
WARNING..SO BE ON THE LOOKOUT AND BE PREPARED TO MOVE TO A PLACE
OF SAFETY IF ONE IS SPOTTED.

JOSEPHS

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.

In the hours before

Special weather statement, Aug 11, 11:37 AM CDT, 3 hours 13 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FARGO ND
1130 AM CDT TUE AUG 11 1987

...THUNDERSTORMS ACROSS THE NORTHEAST CORNER OF NORTH DAKOTA...

AT 1130 AM CDT...SCATTERED SHOWERS AND THUNDERSTORMS...ONE WITH VERY
HEAVY RAIN...CONTINUED OVER THE NORTHEAST CORNER OF NORTH DAKOTA.
THESE STORMS WERE IN A 20 MILE WIDE BAND FROM 40 MILES NORTHWEST OF
GRAND FORKS NEAR WHITMAN NORTHEAST THROUGH THE PEMBINA AREA AND INTO
SOUTHERN CANADA.

AT 1100 AM CDT MARBLE SIZED HAIL WAS REPORTED IN SOUTHEAST CAVALIER
COUNTY NEAR MILTON OR AROUND 50 MILES NORTHWEST OF GRAND FORKS.
THESE STORMS WERE MOVING EAST AT 30 MILES AN HOUR AND WILL BE IN THE
GRAFTON...PARK RIVER AND PEMBINA AREAS BY 1230 PM CDT. SMALL HAIL
AND VERY HEAVY RAIN CAN BE EXPECTED WITH THE PASSAGE OF THESE STORMS.
VOELKER

Special weather statement, Aug 11, 2:36 PM CDT, 14 minutes before

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE FARGO ND
230 PM CDT TUE AUG 11 1987

    ...STRONG THUNDERSTORM OVER EXTREME NORTHWEST MINNESOTA...

AT 230 PM CDT...AN ISOLATED STRONG THUNDERSTORM HAD DEVELOPED OVER
EXTREME NORTHWEST MINNESOTA 30 MILES NORTH OF THIEF RIVER FALLS.
THIS STORM WAS MOVING EAST AT 25 MILES AN HOUR AND WILL BE IN THE
WANNASKA AREA BY 330 PM CDT. VERY HEAVY RAIN...GUSTY WINDS AND SOME
HAIL IS POSSIBLE WITH THIS STORM.

ELSEWHERE...SCATTERED RAINSHOWERS CONTINUED OVER PARTS OF CENTRAL AND
NORTHEAST NORTH DAKOTA. THESE SHOWERS WERE FROM JUST NORTH OF JAMESTOWN
NORTHEAST TO NEAR PEMBINA OR 60 MILES NORTH OF GRAND FORKS.

MOVEMENT WAS EAST AT 25 MILES AN HOUR.
VOELKER

Nearby

Severe Thunderstorm Warnings in Minnesota, 1987 Every severe thunderstorm warning 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.