Alert archive / North Dakota / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 346, NWS Grand Forks, ND

August 21, 2001Cavalier County, Towner County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 21, 2001, 7:28 PM CDT for Cavalier County, Towner County, North Dakota. It was in force for 47 min. 1 report came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued: Aug 21, 2001, 7:28 PM CDT (00:28 UTC)
Expired: Aug 21, 2001, 8:15 PM CDT
In force: 47 min
Issued by: NWS Grand Forks, ND
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Cavalier County, ND, Towner County, ND

What was reported inside it

Time	Report	Where	Remark
Aug 21, 8:15 PM CDT	Hail 1.75	Hansboro, 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, 0.5 hours before the alert went out and 279 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: 2988 J/kg
Mixed-layer CIN: -114 J/kg
Mixed-layer LCL: 1541 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 20 m²/s²
0-3 km storm-relative helicity: 19 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

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

000 
WUUS53 KFGF 220029
SVRFAR
NDC019-095-220115-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE EASTERN ND-GRAND FORKS
728 PM CDT TUE AUG 21 2001

THE NATIONAL WEATHER SERVICE IN GRAND FORKS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...

  NORTHERN TOWNER COUNTY IN NORTH CENTRAL NORTH DAKOTA AND           
  CAVALIER COUNTY IN NORTHEAST NORTH DAKOTA.

* UNTIL 815 PM CDT.

* AT 723 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 11 MILES NORTHEAST OF HANSBORO...OR ABOUT 45
  MILES NORTHWEST OF LANGDON...MOVEMENT WAS TO THE SOUTHEAST AT 10
  MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...

  SARLES AT 815 PM.
  HANNAH AT 830 PM.

REMEMBER SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES WITH LITTLE OR NO ADVANCE WARNING.

LAT...LON 4921 9929 4896 9947 4876 9870 4898 9847


$$
BERG
NNNN

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 21, 2:05 PM CDT, 5 hours 23 minutes earlier.

Area forecast discussion, Aug 21, 2:05 PM CDT, 5 hours 23 minutes before

FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
205 PM CDT TUE AUG 21 2001

CONVECTIVE THREAT IS THE MAIN FORECAST CHALLENGE TONIGHT. MODELS IN
REASONABLE AGREEMENT IN THE UPPER LEVEL FEATURES FOR THE NEXT 48
HOURS BUT THERE ARE SOME MINOR DIFFERENCES AT THE SFC/850 MB. IN THE
SHORT TERM...ETA DOING BEST WITH SFC TEMPS WHILE AVN BEST WITH THE
SLOW EASTWARD PROGRESSION OF THE SFC FRONT. LIKE THE DRIER QPF WITH
THE ETA...SO WILL USE A BLEND OF THE ETA AND AVN.

FRONT PUSHES INTO THE NORTHERN VALLEY AFTER 00Z TONIGHT. SFC/850 MB
FORCING ALONG THE FRONT HAS BEEN WEAK ALL DAY AND THIS REMAINS THE
CASE TONIGHT. BEST FORCING IS IN ONTARIO AND THE CENTRAL PLAINS.
UPPER SUPPORT ALSO WEAK...BUT AGREE WITH SPC SWODY1 THAT CANADIAN
BORDER REGION IN NORTHWEST MN STANDS THE BEST CHANCE OF AN ISOLATED
STORM. FWC/MAV GUIDANCE CLOSE AND WILL FOLLOW.

SFC HIGH PRESSURE BUILDS INTO THE REGION ON WED WITH NORTHEAST WIND
FLOW ADVECTING IN DRIER AIR. AVN HANGING UP FRONTAL BOUNDARY ALONG A
KISN TO KBDE LINE WITH MAX QPF AT 12Z WED. ETA FRONTAL POSITION MUCH
FURTHER EAST. THEREFORE ETA SHOWS CAPE AROUND 1200 J/KG WITH LIS AT
-5 ACROSS SOUTHEAST ZONES AT 12Z WED. HOWEVER...ONCE AGAIN AREA
UNDER NVA AND Q VECTOR DIVERGENCE. 300 MB WINDS STARTING TO BECOME
RATHER ANEMIC IN THE MORNING. SO WILL NOT CARRY A LOW POP EARLY WED
ACROSS THE SOUTHEAST ZONES. SOME COOLING IN THE 850-700 MB LAYER
ESPECIALLY IN NORTHEAST ZONES...SO MOST AREAS WILL SEE TEMPS SIMILAR
TO TODAY OR SLIGHTLY COOLER. GOOD DRYING WED NIGHT WITH COOLER TEMPS
AS A RESULT OF THE DRIER AIR. RETURN FLOW SETS UP ON THU WHILE
PRESSURE GRADIENT BEGINS TO TIGHTEN ACROSS WESTERN AND CENTRAL ND.

.EXTENDED...LARGE SCALE PATTERN CHANGE WILL TAKE PLACE DURING THE
EXTENDED PERIOD AS UPPER LEVEL TROUGH CURRENTLY OVER THE PACIFIC
NORTHWEST DIGS INTO THE CENTER OF THE CONTINENT. EXTENDED MODELS
AGREE ON GENERAL DETAILS. THUNDERSTORMS ARE EXPECTED FRIDAY INTO
EARLY SATURDAY ALONG AND AHEAD OF SIGNIFICANT FROPA. A HINT OF
SEPTEMBER-LIKE WEATHER SHOULD BE IN PLACE FOR THE WEEKEND WITH
RETURN FLOW STARTING A SLOW WARMING TREND ON TUESDAY.

.FGF...NONE.

GODON/BRAMER

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 21, 8:16 PM CDT	Severe Thunderstorm Warning	FGF	Cavalier, Towner	44 min
Aug 22, 12:45 AM CDT	Severe Thunderstorm Warning	FGF	Pembina	60 min

Nearby

Severe Thunderstorm Warnings in North Dakota, 2001 Every severe thunderstorm warning in 2001

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.