Alert archive / North Dakota / Tornado Warnings in 1999

Tornado Warning 32, NWS Grand Forks, ND

July 22, 1999Cass County, North Dakota

NWS Grand Forks, ND issued this tornado warning at Jul 22, 1999, 7:06 PM CDT for Cass County, North Dakota. It was in force for 34 min. 4 reports 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
Jul 22, 1999, 7:06 PM CDT (00:06 UTC)
Expired
Jul 22, 1999, 7:40 PM CDT
In force
34 min
Issued by
NWS Grand Forks, ND
Area
Whole counties

County Cass County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 66 km from the middle of the area, began a volume at 00:09 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
Jul 22, 7:10 PM CDTHail 1Leonard, ND
Jul 22, 7:10 PM CDTThunderstorm WindLeonard, NDTrees were blown down.
Jul 22, 7:20 PM CDTHail 1.75Tower City, ND
Jul 22, 7:30 PM CDTHail 0.75Leonard, 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 22, 5:15 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 0.1 hours before the alert went out and 243 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 00:00Z on 1999-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2442 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 00:00Z on 1999-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 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
2442 J/kg
Mixed-layer CIN
-32 J/kg
Mixed-layer LCL
1803 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
24 m²/s²
0-3 km storm-relative helicity
5 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.8

Open this sounding in Storm Lab

The text

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

021 
WFUS1 KFAR 230006 RRA
TORFAR
NDC017-230040-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
706 PM CDT THU JUL 22 1999

THE NATIONAL WEATHER SERVICE IN GRAND FORKS HAS ISSUED A

* TORNADO WARNING FOR...
  EXTREME SOUTHWESTERN CASS COUNTY IN SOUTHEASTERN NORTH DAKOTA

* UNTIL 740 PM CDT

* AT 703 PM CDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A TORNADO 25 MILES SOUTHEAST OF VALLEY CITY OR 7 MILES SOUTHWEST
  OF ALICE... MOVING EAST AT 10 MPH.

* THE TORNADO WILL BE AROUND 10 MILES WEST OF LEONARD BY 730 PM
  CDT.

THIS IS A DANGEROUS STORM. IF YOU ARE IN THE PATH OF A TORNADO
ABANDON CARS AND MOBILE HOMES FOR A STURDY BUILDING.

HOPPES

What forecasters said that day

The local office's own words before this tornado 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 tornado warning went out at Jul 22, 3:10 PM CDT, 3 hours 56 minutes earlier.

Area forecast discussion, Jul 22, 3:10 PM CDT, 3 hours 56 minutes before
FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
310 PM CDT WED JUL 22 1999

FORECAST PROBLEM FOR TONIGHT IS PCPN. LATEST VIS SATELLITE IMAGERY HAS
AC AND CI WITH EMBEDDED TSRA ALONG SPEED CONVERGENCE BOUNDARY THROUGH
CENTER OF CWFA. LATEST ADAP HAS LIS OF AROUND -10 WITH A SFC MOISTURE
CONVERENCE MAX NEAR DVL AND ABOUT A 2 DEGREE CAP. MODELS SIMILAR IN
TREATMENT OF SHORTWAVE AS IT LIFTS N FROM SD THROUGH ND SIDE OF CWFA BY
06Z. STILL PREFER ETA SOLUTION OVER OTHER MODELS SINCE IT HAS HAD THE
BEST ACCURACY AND CONSISTENCY OVER THE PAST FEW DAYS. POTENTIAL REMAINS
FOR SVR OVER CWFA AS THE WAVE MOVES THROUGH. THEREFORE...WILL LEAVE
EVENING TSRA WITH POSSIBLE SVR IN FORECAST FOR THIS EVENING.

FORECAST PROBLEM FOR 2ND THROUGH 4TH PERIOD IS TEMPS. MODELS CONTINUE
TO KEEP 500MB RIDGE OVER NORTHERN PLAINS WITH SHORTWAVES RIDING THROUGH.
HOWEVER...BEST UVV REMAINS W OF CWFA AS A LOW PRESSURE SYSTEM DEVELOPS
IN E MT BY SAT. GOOD WAA REMAINS AHEAD OF THIS NEXT LOW PRESSURE
SYSTEM...KEEPING HOT AND HUMID CONDITIONS OVER THE CWFA INTO SAT.

EXTENDED FORECAST...AFTER VERY WARM AND SULTRY SATURDAY...EXPECT
SOUTHWARD EXPANDING WESTERLIES TO SWEEP FAIRLY SIGNIFICANT COLD FRONT
ACROSS THE REGION SUNDAY ACCOMPANIED BY THE POTENTIAL FOR RATHER HEFTY
THUNDERSTORMS. COOLER AND DRIER CONDITIONS SHOULD THEN FOLLOW IN ITS
WAKE FOR MONDAY AND TUESDAY.

.FGF...NONE

NG/BERG
Hazardous weather outlook, Jul 22, 11:31 AM CDT, 7 hours 35 minutes before
MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052-053-221915-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
1131 AM CDT THU JUL 22 1999

...SEVERE THUNDERSTORMS ARE EXPECTED ACROSS EASTERN NORTH DAKOTA AND
NORTHWEST AND WEST CENTRAL MINNESOTA THIS AFTERNOON AND EVENING...

SYNOPSIS...UNSTABLE AIR WILL REMAIN IN PLACE FOR THE REMAINDER OF
THE AFTERNOON...WITH DEW POINTS IN THE LOWER 70S AND TEMPERATURES
OF AROUND 90. AN UPPER LEVEL TROUGH AND WEAK SURFACE COLD FRONT
WILL APPROACH THE REGION THIS AFTERNOON...AND PASS THROUGH THE AREA
BY MIDNIGHT.

AREA OF CONCERN...A MODERATE RISK OF SEVERE THUNDERSTORMS IS
FORECAST FOR AREAS OF EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
FROM COOPERSTOWN TO MAYVILLE TO BEMIDJI AND POINTS NORTH. SOUTH OF
THIS LINE A SLIGHT CHANCE OF SEVERE THUNDERSTORMS IS FORECAST.

TIME...BETWEEN 4 PM AND MIDNIGHT.

TYPE OF HAZARD...MAINLY STRAIGHT LINE WIND DAMAGE...LARGE HAIL AND
ISOLATED TORNADOES.

KELLENBENZ/BRAZZELL

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 22, 7:37 PM CDTSevere Thunderstorm WarningFGFCass48 min
Jul 22, 7:44 PM CDTSevere Thunderstorm WarningFGFRansom36 min
Jul 22, 8:00 PM CDTSevere Thunderstorm WarningFGFTraill35 min
Jul 22, 8:08 PM CDTFlash Flood WarningFGFCass3 hr
Jul 22, 9:10 PM CDTSevere Thunderstorm WarningFGFTraill35 min
Jul 23, 12:10 PM CDTSevere Thunderstorm WarningFGFGrand Forks35 min

Nearby

Tornado Warnings in North Dakota, 1999Every tornado warning in 1999Tornadoes in 1999

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.