Alert archive / Minnesota / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 208, NWS Grand Forks, ND

September 7, 1997Pennington County, Polk County, Minnesota

NWS Grand Forks, ND issued this severe thunderstorm warning at Sep 7, 1997, 9:29 PM CDT for Pennington County, Polk County, Minnesota. It was in force for 31 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Sep 7, 1997, 9:29 PM CDT (02:29 UTC)
Expired
Sep 7, 1997, 10:00 PM CDT
In force
31 min
Issued by
NWS Grand Forks, ND
Area
Whole counties

Counties Pennington County, MN, Polk County, MN

The radar

The Fargo/Grand Forks radar (KMVX), 93 km from the middle of the area, began a volume at 02:32 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.

The nearest sounding before it

International Fa, MN (KINL), launched 00:00Z, 2.5 hours before the alert went out and 228 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 1997-09-08Temperature 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 1997-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 160 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
709 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
160 m²/s²
0-3 km storm-relative helicity
220 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 080231 RRA
SVRFAR
MNC113-119-080300-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
929 PM CDT SUN SEP 7 1997
 
THE NATIONAL WEATHER SERVICE IN EASTERN ND/GRAND FORKS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1000 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN NORTHWEST MINNESOTA
 
   ...WESTERN PENNINGTON COUNTY...WESTERN POLK COUNTY
 
AT 928 PM...RADAR INDICATED A SEVERE THUNDERSTORM 11 MILES SOUTHWEST OF
THIEF RIVER FALLS MOVING EAST AT 25 MPH. THIS STORM WILL EFFECT THE TOWN
OF ST. HILAIRE.
 
REMEMBER SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO
PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE WARNING.
 
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, 27 minutes earlier.

Area forecast discussion, Sep 7, 9:02 PM CDT, 27 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, 7:06 PM CDTSevere Thunderstorm WarningFGFRoseau39 min
Sep 7, 7:34 PM CDTSevere Thunderstorm WarningFGFKittson26 min
Sep 7, 7:44 PM CDTSevere Thunderstorm WarningFGFRoseau31 min
Sep 7, 8:32 PM CDTSevere Thunderstorm WarningFGFMarshall28 min
Sep 7, 9:03 PM CDTSevere Thunderstorm WarningFGFMarshall, Polk27 min
Sep 7, 10:00 PM CDTSevere Thunderstorm WarningFGFPolk30 min
Sep 7, 10:31 PM CDTSevere Thunderstorm WarningFGFNorman, Polk29 min
Sep 7, 11:37 PM CDTSevere Thunderstorm WarningFGFClay38 min
Sep 7, 11:50 PM CDTSevere Thunderstorm WarningFGFClay40 min
Sep 8, 12:30 AM CDTSevere Thunderstorm WarningFGFClay30 min
Sep 8, 12:40 AM CDTSevere Thunderstorm WarningFGFWilkin35 min
Sep 8, 4:22 PM CDTSevere Thunderstorm WarningFGFWilkin38 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.