Alert archive / North Dakota / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 207, NWS Grand Forks, ND

September 7, 1997Grand Forks County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Sep 7, 1997, 9:07 PM CDT for Grand Forks County, North Dakota. It was in force for 38 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Sep 7, 1997, 9:07 PM CDT (02:07 UTC)
Expired
Sep 7, 1997, 9:45 PM CDT
In force
38 min
Issued by
NWS Grand Forks, ND
Area
Whole counties

County Grand Forks County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 45 km from the middle of the area, began a volume at 02:09 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.

What was reported inside it

TimeReportWhereRemark
Sep 7, 9:25 PM CDTHail 0.75Thompson, ND

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.

The nearest sounding before it

Bismarck Municip, ND (KBIS), launched 00:00Z, 2.1 hours before the alert went out and 276 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, Bismarck Municip, ND at 00:00Z on 1997-09-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 54 joules per kilogram.LCLLFCEL10008507005003002001001 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, Bismarck Municip, ND at 00:00Z on 1997-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 5 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
54 J/kg
Mixed-layer CIN
-75 J/kg
Mixed-layer LCL
2572 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
5 m²/s²
0-3 km storm-relative helicity
90 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.

000 
TTAA00 KFAR 080209 RRA
SVRFAR
NDC035-080245-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
907 PM CDT SUN SEP 7 1997
 
THE NATIONAL WEATHER SERVICE IN EASTERN ND/GRAND FORKS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  945 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN NORTHEAST NORTH DAKOTA
 
   ...EASTERN GRAND FORKS COUNTY
 
AT 906 PM...RADAR INDICATED A SEVERE THUNDERSTORM 10 MILES WEST OF
THOMPSON OR 17 MILES SOUTHWEST OF GRAND FORKS. THIS STROM IS MOVING TO
THE EAST AT 15 MPH AND WILL EFFECT THE CITY OF THOMPSON.
 
REMEMBER SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO
PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE WARNIN8G.
 
GSF

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 Sep 7, 9:02 PM CDT, 5 minutes earlier.

Area forecast discussion, Sep 7, 9:02 PM CDT, 5 minutes before
FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
901 PM CDT SUN SEP 7 1997

FIRST PERIOD DISCUSSION...GENERAL TREND ON STRMS ON 88D HAS BEEN
ON THE DCRS ESPECIALLY IN ERN ND. HOWEVER IR IMAGERY HAS SOME
BUILDING TO THE SW. 88D VAD WND HAS RELATIVELY WK WNDS ALFT
MAKING FOR PULSE STORMS. LOW LVL FLO ON VAD WND HAS INCRSD
A BIT IN LAST HALF HOUR. ADAP CONTS TO SHOW SFC MOIST CNVG
IN NRN CNTYS BUT LESS THAN EARLIER PLOTS. BEST INSTABLILITES
REMAIN AHEAD OF CD FNT. WITH SFC HTG GONE XPCT STRMS TO CONT
TO DROP BLO SVR LVLS. HOWEVER LLJ MAY KEEP THINGS ALIVE FOR A WHILE.

HOPPES

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 7, 7:15 PM CDTSevere Thunderstorm WarningFGFWalsh30 min
Sep 7, 7:47 PM CDTSevere Thunderstorm WarningFGFGriggs28 min
Sep 7, 8:13 PM CDTSevere Thunderstorm WarningFGFWalsh17 min
Sep 7, 11:37 PM CDTSevere Thunderstorm WarningFGFCass38 min
Sep 7, 11:50 PM CDTSevere Thunderstorm WarningFGFCass40 min
Sep 8, 12:30 AM CDTSevere Thunderstorm WarningFGFCass30 min
Sep 8, 12:40 AM CDTSevere Thunderstorm WarningFGFRichland35 min
Sep 8, 4:22 PM CDTSevere Thunderstorm WarningFGFRichland38 min

Nearby

Severe Thunderstorm Warnings in North Dakota, 1997Every severe thunderstorm warning in 1997

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; radar from the NEXRAD Level II archive.