Alert archive / Minnesota / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 237, NWS Grand Forks, ND

August 31, 1998Mahnomen County, Minnesota

NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 31, 1998, 4:36 PM CDT for Mahnomen County, Minnesota. It was in force for 34 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: Aug 31, 1998, 4:36 PM CDT (21:36 UTC)
Expired: Aug 31, 1998, 5:10 PM CDT
In force: 34 min
Issued by: NWS Grand Forks, ND
Area: Whole counties

County Mahnomen County, MN

The nearest sounding before it

International Fa, MN (KINL), launched 12:00Z, 9.6 hours before the alert went out and 233 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1998 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 72 m²/s²
0-3 km storm-relative helicity: 116 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.

600 
WUUS1 KFAR 312139 RRA
SVRFAR
MNC087-312210-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
436 PM CDT MON AUG 31 1998

THE NATIONAL WEATHER SERVICE IN GRAND FORKS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  MAHNOMEN COUNTY IN NORTHWESTERN MINNESOTA

* UNTIL 510 PM CDT

* AT 435 PM CDT DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 5 MILES
  SOUTHWEST OF FOSSTON...OR 40 MILES WEST OF BEMIDJI. THE WAS MOVING
  SOUTHEAST AT 15 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  SUGAR BOWL LAKE BY 450 PM CDT
  ISLAND LAKE BY 500 PM CDT

IF SEVERE WEATHER IS OBSERVED CONTACT YOUR LOCAL LAW ENFORCEMENT
AND ASK THEM TO RELAY YOUR INFORMATION TO THE NATIONAL WEATHER
SERVICE.

KENNEDY

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 Aug 31, 3:23 PM CDT, 1 hour 13 minutes earlier.

Area forecast discussion, Aug 31, 3:23 PM CDT, 1 hour 13 minutes before

FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
250 PM CDT MON AUG 31 1998

FORECAST CHALLENGE TONIGHT WILL BE EARLY TSRA THREAT AND OVERNIGHT
MINS. DATA HAS BEEN SPARSE THIS SHIFT WITH GRIDDED DATA NOT YET
AVAILABLE...SAT DATA OLD AND SPORADIC. 18Z SFC MAP INDICATING COLD
FRONT FROM NEAR NE CORNER OF ND TO BETWEEN BIS AND DIK WITH ANOTHER WK
BOUNDARY/WARM FRONT FROM NEAR ROX TO BJI. CONVECTION WHICH PROPAGATED
FROM S MB INTO NW MN APPEARS TO BE FOLLOWING THE LATER BOUNDARY ACROSS
NW MN. INL SOUNDING ALSO INDICATED FAIRLY GOOD H8 WAA WHICH ALSO AIDED
IN SUSTAINING CONVECTION. FROM 12Z RUC SHORTWAVE AND JET DYNAMICS
PROGGED TO REMAIN N OF BORDER. ALSO LOW LEVEL MOIST SOMEWHAT IN
QUESTION AS AREA 12Z SOUNDINGS FAIRLY DRY RESULTING IN MAINLY ELEVATED
CONVECTION. SFC DEWPOINTS CONTINUE IN THE MID TO UPPER 50S WITH ISOLD
60 DEGREE READINGS AHEAD OF CF. H8 FLOW OF 20-30KTS GETS CUT OFF OVR
NEBRASKA SO AM NOT EXPECTING ANY SUSTAINED LOW LEVEL MOIST TRANSPORT.
AS A RESULT EXPECT ANY CONVECTION TO BE WIDELY SCATTERED/ISOLATED. AM
SLIGHTLY CONCERN ABOUT OUTFLOW BOUNDARY WHICH IS EVIDENT FROM KMVX-88D
AND VIS LOOP WHICH MAY INTERACT WITH APPROACHING COLD FRONT ACROSS
EASTERN ND EARLY THIS EVENING. ALSO ADAP INDICATING LI'S -4 TO -6 WITH
WK MOIST CONVERGENCE SO STILL FEEL SOME MENTION OF TSRA NEEDED EVEN
WITH LACK OF UPPER AIR SUPPORT. OTHERWISE CU FIELD HAS SHOWN A RECENT
DISSIPATING TREND. LATER THIS EVENING POST CFP CAA GETS GOING AND
CONTINUES OVERNIGHT INTO SECOND PERIOD. IMPRESSIVE DEWPOINTS IN THE MID
30S AS CLOSE AS SE SASK. WITH SFC GRADIENT AND SIG PRESS RISES MIXING
MAY HOLD TEMPS UP SOMEWHAT OVERNIGHT. WITH LACK OF GRIDDED DATA TO LOOK
AT FEEL GUIDAANCE TEMPS GOOD PLACE TO START. PRELIMINARY GUIDANCE FOR
COORDINATION ONLY.
FOR DVL...MOCLR. LOW 45 TO 50. NW WIND 10 TO 15 MPH.
GFK...ISOLD EARLY EVENING TSRA OTWS MOCLR. LOW 45 TO 50. WIND BECOMING
NW 10 TO 15 MPH.
FAR...ISOLD EARLY EVENING TSRA OTWS MOCLR. LOW AROUND 50. WIND BECOMING
NW 5 TO 15 MPH.
MN4-9>13-17
.TONIGHT...ISOLD EARLY EVENING TSRA OTWS CLEARING. LOW UPPER 40S TO
LOWER 50S. WIND BECOMING NW 10 TO 15 MPH.
MN22-24>27-32>40
.TONIGHT...AN ISOLD EARLY EVENING TSRA POSSIBLE OTHERWISE MOCLR. LOW
AROUND 50. WIND BECOMING NW 5 TO 15 MPH.
VOELKER

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 31, 4:15 PM CDT	Severe Thunderstorm Warning	FGF	Polk	35 min
Aug 31, 4:52 PM CDT	Severe Thunderstorm Warning	FGF	Kittson	33 min
Aug 31, 5:37 PM CDT	Severe Thunderstorm Warning	FGF	Kittson	33 min
Aug 31, 6:07 PM CDT	Severe Thunderstorm Warning	FGF	Kittson	33 min
Aug 31, 6:23 PM CDT	Severe Thunderstorm Warning	FGF	Marshall	32 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 1998 Every severe thunderstorm warning in 1998

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.