Alert archive / North Dakota / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 217, NWS Grand Forks, ND

August 18, 1998Towner County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 18, 1998, 9:28 AM CDT for Towner County, North Dakota. It was in force for 32 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 18, 1998, 9:28 AM CDT (14:28 UTC)
Expired
Aug 18, 1998, 10:00 AM CDT
In force
32 min
Issued by
NWS Grand Forks, ND
Area
Whole counties

County Towner County, ND

The radar

The Minot AFB radar (KMBX), 124 km from the middle of the area, began a volume at 14:32 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

Bismarck Municip, ND (KBIS), launched 12:00Z, 2.5 hours before the alert went out and 239 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 12:00Z on 1998-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1285 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 12:00Z on 1998-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 238 square meters per square second.19395878Sfc1 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
1285 J/kg
Mixed-layer CIN
-141 J/kg
Mixed-layer LCL
577 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
238 m²/s²
0-3 km storm-relative helicity
321 m²/s²
Significant tornado parameter
0.0
Supercell composite
10.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFAR 181431 RRA
SVRFAR
NDC095-181500-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
928 AM CDT TUE AUG 18 1998

THE NATIONAL WEATHER SERVICE IN EASTERN ND/GRAND FORKS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  TOWNER COUNTY IN NORTH CENTRAL NORTH DAKOTA

* UNTIL 1000 AM CDT

* AT 926 AM CDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A SEVERE THUNDERSTORM 43 MILES WEST OF LANGDON OR 4 MILES
  NORTHEAST OF BISBEE MOVING NORTHEAST AT 30 MPH.

 THE SEVERE THUNDERSTORM WILL BE NEAR

 ROCKLAKE

DURING THUNDERSTORMS YOU SHOULD MOVE INSIDE A STRONG BUILDING.
DO NOT STAND BY WINDOWS.  DO NOT USE TELEPHONES OR ELECTRICALN
APPLIANCES.

KELLENBENZ

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 18, 5:50 AM CDT, 3 hours 38 minutes earlier.

Area forecast discussion, Aug 18, 5:50 AM CDT, 3 hours 38 minutes before
FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
550 AM CDT TUE AUG 18 1998

UPDATED NEEDED FOR ND SIDE.  MY ORIGINAL IDEA OF TRYING TO HOLD OFF MAIN
TSTM THREAT TIL THE AFTERNOON ACROSS THE VALLEY DOES NOT APPEAR TO BE
WORKING OUT.  LINE OF TSTMS FROM JUST SOUTH OF DVL TO JMS WILL LIKELY
CONTINUE TO TREEK NORTHEAST AND MOVE THROUGH THE VALLEY LATER THIS
MORNING.

THUS WILL UPDATE AND JUST GO SCATTERED SHOWERS/TSTMS ANYTIME FOR
GFK/FAR ZONES.   WILL LEAVE WORDING NW MN ZONES ALONE AND WAIT AND SEE
HOW LINE PROGRESSES THROUGH THE MORNING.

UPDATE OUT SHORTLY.

RIDDLE

In the hours before

Special weather statement, Aug 18, 6:55 AM CDT, 2 hours 33 minutes before
MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052-053-181400-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
655 AM CDT TUE AUG 18 1998

...ISOLATED SEVERE THUNDERSTORMS WILL BE POSSIBLE TODAY AND
TONIGHT...

LOW PRESSURE WAS OVER EASTERN MONTANA WITH A WARM FRONT THROUGH CENTRAL
SOUTH DAKOTA.  DURING THE DAY...THE LOW WILL MOVE SLOWLY EAST WHILE THE
WARM FRONT MOVES NORTH TO ALONG THE NORTH AND SOUTH DAKOTA BORDER.

MOIST AND UNSTABLE AIR WILL MOVE NORTH INTO EASTERN NORTH DAKOTA TODAY
AND INTO NORTHWEST MINNESOTA TONIGHT.  THIS WILL CAUSE THE DEVELOPMENT
OF SCATTERED THUNDERSTORMS.  THE BEST CHANCE FOR ORGANIZED
THUNDERSTORMS WILL BE TONIGHT.

ISOLATED SEVERE THUNDERSTORMS WILL BE POSSIBLE WITH THIS SYSTEM...WITH
THE BEST CHANCE BEING TONIGHT.  LARGE HAIL WILL BE THE MAIN THREAT
ALONG WITH HEAVY RAINFALL.

RIDDLE
Special weather statement, Aug 18, 6:55 AM CDT, 2 hours 33 minutes before
MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052-053-181400-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
655 AM CDT TUE AUG 18 1998

...ISOLATED SEVERE THUNDERSTORMS WILL BE POSSIBLE TODAY AND
TONIGHT...

LOW PRESSURE WAS OVER EASTERN MONTANA WITH A WARM FRONT THROUGH CENTRAL
SOUTH DAKOTA.  DURING THE DAY...THE LOW WILL MOVE SLOWLY EAST WHILE THE
WARM FRONT MOVES NORTH TO ALONG THE NORTH AND SOUTH DAKOTA BORDER.

MOIST AND UNSTABLE AIR WILL MOVE NORTH INTO EASTERN NORTH DAKOTA TODAY
AND INTO NORTHWEST MINNESOTA TONIGHT.  THIS WILL CAUSE THE DEVELOPMENT
OF SCATTERED THUNDERSTORMS.  THE BEST CHANCE FOR ORGANIZED
THUNDERSTORMS WILL BE TONIGHT.

ISOLATED SEVERE THUNDERSTORMS WILL BE POSSIBLE WITH THIS SYSTEM...WITH
THE BEST CHANCE BEING TONIGHT.  LARGE HAIL WILL BE THE MAIN THREAT
ALONG WITH HEAVY RAINFALL.

RIDDLE

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 5:16 PM CDTSevere Thunderstorm WarningFGFBarnes, Cass34 min
Aug 18, 5:48 PM CDTSevere Thunderstorm WarningFGFCass32 min

Nearby

Severe Thunderstorm Warnings in North Dakota, 1998Every 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; radar from the NEXRAD Level II archive.