Alert archive / North Dakota / Tornado Warnings in 2011

Tornado Warning 25, NWS Grand Forks, ND

July 4, 2011Cass County, North Dakota

NWS Grand Forks, ND issued this tornado warning at Jul 4, 2011, 9:51 PM CDT for Cass County, North Dakota. It was in force for 39 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 4, 2011, 9:51 PM CDT (02:51 UTC)
Expired: Jul 4, 2011, 10:30 PM CDT
In force: 39 min
Issued by: NWS Grand Forks, ND
Area: Storm-based polygon

County Cass County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 78 km from the middle of the area, began a volume at 02:50 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

Time	Report	Where	Remark
Jul 4, 10:00 PM CDT	FUNNEL CLOUD	12 Nw West Fargo, ND	DISTANCE ESTIMATED AND COORDINATED WITH RADAR SIGNATURE.
Jul 4, 10:02 PM CDT	TORNADO	5 Nw Mapleton, ND	PUBLIC REPORT OF A TORNADO 5 NW OF MAPLETON RELAYED THROUGH DISPATCH.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

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

Issued	Product	Office	Lasted
Jul 4, 3:06 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 4, 7:14 PM CDT	Severe Thunderstorm Watch	SPC	9 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 2.9 hours before the alert went out and 245 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: 3256 J/kg
Mixed-layer CIN: -52 J/kg
Mixed-layer LCL: 1088 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 94 m²/s²
0-3 km storm-relative helicity: 150 m²/s²
Significant tornado parameter: 1.3
Supercell composite: 9.4

Open this sounding in Storm Lab

The text

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

586 
WFUS53 KFGF 050251
TORFGF
NDC017-050330-
/O.NEW.KFGF.TO.W.0025.110705T0251Z-110705T0330Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
951 PM CDT MON JUL 4 2011

THE NATIONAL WEATHER SERVICE IN GRAND FORKS HAS ISSUED A

* TORNADO WARNING FOR...
  EASTERN CASS COUNTY IN SOUTHEAST NORTH DAKOTA...

* UNTIL 1030 PM CDT

* AT 946 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THE STORM WAS
  LOCATED 3 MILES EAST OF AMENIA...OR 18 MILES NORTHWEST OF FARGO...
  MOVING TO THE SOUTHEAST AT 25 MPH.

* THE TORNADIC STORM WILL BE NEAR...
  PROSPER AROUND 1000 PM CDT.
  MAPLETON AROUND 1005 PM CDT.
  WEST FARGO AROUND 1020 PM CDT.
  PRAIRIE ROSE AND DAVENPORT AROUND 1025 PM CDT.

THEREAFTER SOME OTHER LOCATIONS IMPACTED BY THE TORNADIC STORM
INCLUDE HORACE.

FOR MOTORISTS ON INTERSTATE 94...THE TORNADIC STORM WILL BE
BETWEEN...MILE MARKER 336 AROUND 1005 PM CDT...AND MILE MARKER 343
AROUND 1015 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4683 9680 4679 9680 4669 9704 4699 9732
      4710 9710
TIME...MOT...LOC 0251Z 325DEG 22KT 4697 9713

$$

HOPPES

2 follow-up statements

664 
WWUS53 KFGF 050307
SVSFGF

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
1007 PM CDT MON JUL 4 2011

NDC017-050330-
/O.CON.KFGF.TO.W.0025.000000T0000Z-110705T0330Z/
CASS ND-
1007 PM CDT MON JUL 4 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR EASTERN CASS COUNTY IN
SOUTHEAST NORTH DAKOTA UNTIL 1030 PM CDT...

AT 1004 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 3 MILES NORTH OF
MAPLETON...OR 12 MILES WEST OF FARGO...MOVING TO THE SOUTHEAST AT 20
MPH.

THE TORNADIC STORM WILL BE NEAR...
  WEST FARGO AROUND 1025 PM CDT.
  HORACE...PRAIRIE ROSE AND FRONTIER AROUND 1030 PM CDT.

FOR MOTORISTS ON INTERSTATE 94...THE TORNADIC STORM WILL BE
BETWEEN...MILE MARKER 338 AROUND 1010 PM CDT...AND MILE MARKER 347
AROUND 1030 PM CDT...

A TORNADO WAS REPORTED AT 1002 PM CDT...5 MILES NORTHWEST OF 
MAPLETON BY THE PUBLIC.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4683 9680 4679 9680 4669 9704 4699 9732
      4710 9710
TIME...MOT...LOC 0306Z 319DEG 19KT 4692 9706

$$

HOPPES/EWENS

199 
WWUS53 KFGF 050329
SVSFGF

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
1029 PM CDT MON JUL 4 2011

NDC017-050339-
/O.EXP.KFGF.TO.W.0025.000000T0000Z-110705T0330Z/
CASS ND-
1029 PM CDT MON JUL 4 2011

...THE TORNADO WARNING FOR EASTERN CASS COUNTY IN SOUTHEAST NORTH
DAKOTA WILL EXPIRE AT 1030 PM CDT...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.

LAT...LON 4683 9680 4679 9680 4669 9704 4699 9732
      4710 9710
TIME...MOT...LOC 0329Z 319DEG 19KT 4681 9698

$$

HOPPES/EWENS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 4, 8:17 PM CDT	Severe Thunderstorm Warning	FGF	Traill	58 min
Jul 4, 9:12 PM CDT	Severe Thunderstorm Warning	FGF	Cass, Traill	63 min
Jul 4, 9:21 PM CDT	Tornado Warning	FGF	Cass, Traill	39 min
Jul 4, 9:40 PM CDT	Severe Thunderstorm Warning	FGF	Cass	65 min
Jul 4, 10:26 PM CDT	Severe Thunderstorm Warning	FGF	Cass, Ransom, Richland, Sargent	64 min
Jul 5, 4:06 AM CDT	Areal Flood Advisory	FGF	Richland, Sargent	8 hr
Jul 5, 4:24 AM CDT	Severe Thunderstorm Warning	FGF	Richland	22 min

Nearby

Tornado Warnings in North Dakota, 2011 Every tornado warning in 2011 Tornadoes in 2011

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.