Alert archive / North Dakota / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 121, NWS Grand Forks, ND

July 17, 2002Cass County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Jul 17, 2002, 11:26 AM CDT for Cass County, North Dakota. It was in force for 49 min. 4 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 17, 2002, 11:26 AM CDT (16:26 UTC)
Expired
Jul 17, 2002, 12:15 PM CDT
In force
49 min
Issued by
NWS Grand Forks, ND
Area
Counties, with a storm outline in the text

County Cass County, ND

What was reported inside it

TimeReportWhereRemark
Jul 17, 11:35 AM CDTHail 1.75Tower City, ND
Jul 17, 11:40 AM CDTThunderstorm WindTower City, NDGrain bins were damaged and trees were blown down in Tower City. Three of the city's 8 streets were blocked by trees and power was out for 4 hours. One tree fell on a church, causing substantial damage.
Jul 17, 12:10 PM CDTHail 0.75Alice, ND
Jul 17, 12:10 PM CDTThunderstorm WindAlice, NDTrees were blown down.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 4.4 hours before the alert went out and 241 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 2002-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 243 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 12:00Z on 2002-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 82 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
243 J/kg
Mixed-layer CIN
-416 J/kg
Mixed-layer LCL
2067 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
82 m²/s²
0-3 km storm-relative helicity
84 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

290 
WUUS53 KFGF 171626
SVRFAR
NDC017-171715-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
1125 AM CDT WED JUL 17 2002

THE NATIONAL WEATHER SERVICE IN GRAND FORKS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...

  WESTERN AND CENTRAL CASS COUNTY IN SOUTHEAST NORTH DAKOTA.

* UNTIL 1215 PM CDT.

* AT 1121 AM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 13 MILES NORTHWEST OF BUFFALO...OR ABOUT 12
  MILES NORTHEAST OF VALLEY CITY...MOVEMENT WAS TO THE EAST AT 20
  MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...

  BUFFALO AT 1150 AM...
  AYR AT 1155 AM...
  ERIE AT NOON AND
  CASSELTON AT 1215 PM.

REMEMBER SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES WITH LITTLE OR NO ADVANCE WARNING.

LAT...LON 4712 9769 4676 9766 4673 9719 4710 9716

06

NNNN

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 Forks, ND wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 17, 10:10 AM CDT, 1 hour 16 minutes earlier.

Area forecast discussion, Jul 17, 10:10 AM CDT, 1 hour 16 minutes before
FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
1010 AM CDT WED JUL 17 2002

...MAIN CHALLENGE FOR THIS AFTERNOON WILL BE THUNDERSTORM CHANCES
AND SKY COVER...

.CURRENT OBSERVATIONS...
MCS CURRENTLY MOVING INTO NORTHEAST NORTH DAKOTA ALONG TIGHT 850MB
DEWPOINT GRADIENT. DO NOT EXPECT ANY FLOODING PROBLEMS WITH THIS
FIRST ROUND OF PRECIPITATION. HOWEVER...AREAS THAT HAVE
PRECIPITATION THIS MORNING WILL HAVE TO BE WATCHED IF ANOTHER ROUND
MOVES INTO THE AREA. TEMPERATURES AHEAD OF THE SYSTEM ARE NEAR 80
DEGREES FROM THE RED RIVER VALLEY AND POINTS EAST. MAY NEED TO BUMP
TEMPERATURES UP FOR THE BEMIDJI AND FARGO ZONES AND BRING THUNDER IN
A LITTLE EARLIER. WILL ADJUST CLOUD WORDING FOR DEVILS LAKE AREA TO
BECOMING PARTLY CLOUDY.

.FGF...FLOOD WARNING CONTINUES FOR PORTIONS OF THE RED RIVER NEAR
OSLO.
FLOOD WATCH THIS AFTERNOON AND TONIGHT FOR THE ENTIRE CWA.

DONAVON

In the hours before

Special weather statement, Jul 17, 6:50 AM CDT, 4 hours 36 minutes before
MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052>054-171300-

SPECIAL WEATHER STATEMENT
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
650 AM CDT WED JUL 17 2002

...SEVERE THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING...

.SYNOPSIS...SCATTERED THUNDERSTORMS...SOME POSSIBLE SEVERE...ARE
EXPECTED TO DEVELOP ALONG AND NORTH OF AN OLD FRONTAL BOUNDRY AS A
LOW PRESSURE SYSTEM MOVES EAST ALONG THE BOUNDRY.  THE OLD FRONTAL
SYSTEM REMAINS STATIONARY FROM NORTHERN SOUTH DAKOTA TO THE
MINNESOTA ARROWHEAD.

.AREA OF CONCERN...EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
SOUTH OF US HIGHWAY 2.

.TIME...BEGINNING AFTER 2 PM IN THE DEVILS LAKE REGION AND
SPREADING EAST THROUGH THE AFTERNOON AND EVENING

.TYPE OF HAZARD...LARGE HAIL AND DAMAGING WINDS WITH ISOLATED
TORNADOS POSSIBLE.

KENNEDY

The office that day

Everything else NWS Grand Forks, ND issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 17, 10:45 AM CDTSevere Thunderstorm WarningFGFBarnes45 min
Jul 17, 12:15 PM CDTSevere Thunderstorm WarningFGFCass30 min
Jul 17, 12:31 PM CDTSevere Thunderstorm WarningFGFRansom, Richland59 min
Jul 17, 12:36 PM CDTSevere Thunderstorm WarningFGFRansom, Richland54 min

Nearby

Severe Thunderstorm Warnings in North Dakota, 2002Every severe thunderstorm warning in 2002

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.