Alert archive / North Dakota / Flash Flood Warnings in 2021

Flash Flood Warning 1, NWS Grand Forks, ND

July 15, 2021Grand Forks County, North Dakota

NWS Grand Forks, ND issued this flash flood warning at Jul 15, 2021, 6:49 PM CDT for Grand Forks County, North Dakota. It was in force for 4 hr. 7 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 15, 2021, 6:49 PM CDT (23:49 UTC)
Expired: Jul 15, 2021, 10:45 PM CDT
In force: 4 hr
Issued by: NWS Grand Forks, ND
Area: Storm-based polygon
Flood severity: None

County Grand Forks County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 55 km from the middle of the area, began a volume at 23:48 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
Jul 15, 7:00 PM CDT	HEAVY RAIN 0.7	2 Wsw Honeyford, ND
Jul 15, 7:00 PM CDT	HEAVY RAIN 1.25	5 Sw Honeyford, ND
Jul 15, 7:00 PM CDT	HEAVY RAIN 2.5	3 N Larimore, ND
Jul 15, 7:00 PM CDT	HEAVY RAIN 5.1	5 Nne Larimore, ND
Jul 15, 7:00 PM CDT	HEAVY RAIN 5.2	5 E Mccanna, ND
Jul 15, 7:00 PM CDT	HEAVY RAIN 5.4	4 E Mccanna, ND
Jul 15, 7:00 PM CDT	HEAVY RAIN 6.4	6 E Mccanna, ND

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

The nearest sounding before it

Bismarck Municip, ND (KBIS), launched 12:00Z, 11.8 hours before the alert went out and 273 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: 31 J/kg
Mixed-layer CIN: -157 J/kg
Mixed-layer LCL: 1419 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: -1 m²/s²
0-3 km storm-relative helicity: 20 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

202 
WGUS53 KFGF 152349
FFWFGF
NDC035-160345-
/O.NEW.KFGF.FF.W.0001.210715T2349Z-210716T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Grand Forks ND
649 PM CDT Thu Jul 15 2021

The National Weather Service in Grand Forks has issued a

* Flash Flood Warning for...
  Northwestern Grand Forks County in northeastern North Dakota...

* Until 1045 PM CDT.

* At 649 PM CDT, local law enforcement reported flash flooding north 
  of Larimore. Between 4.5 and 9 inches of rain have fallen. Flash 
  flooding is already occurring.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Law enforcement reported.

  IMPACT...Flash flooding of small creeks and streams, county
           roads, highways, as well as other poor drainage and
           low-lying areas.

* Some locations that will experience flash flooding include...
  McCanna, Turtle River State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Safety message - Turn around, don't drown. Don't travel through 
flooded areas. Most flood deaths occur in vehicles.

&&

LAT...LON 4794 9747 4793 9758 4793 9765 4802 9775
      4811 9765 4811 9754 4804 9751 4797 9747

FLASH FLOOD...OBSERVED

$$

DJR

1 follow-up statement

507 
WGUS73 KFGF 160344
FFSFGF

Flash Flood Statement
National Weather Service Grand Forks ND
1044 PM CDT Thu Jul 15 2021

NDC035-160354-
/O.EXP.KFGF.FF.W.0001.000000T0000Z-210716T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Grand Forks ND-
1044 PM CDT Thu Jul 15 2021

...FLASH FLOOD WARNING AT 1045 PM CDT THIS EVENING FOR NORTHWESTERN 
GRAND FORKS COUNTY HAS BEEN REPLACED WITH A FLOOD WARNING...

The threat for flash flooding has diminished, however overland 
flooding and flooding along the Upper Branch Turtle River will 
continue.

LAT...LON 4794 9747 4793 9758 4793 9765 4802 9775
      4811 9765 4811 9754 4804 9751 4797 9747

$$

DJR

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 15, 3:36 PM CDT	Special Weather Statement	FGF	Grand Forks	24 min
Jul 15, 4:42 PM CDT	Areal Flood Advisory	FGF	Grand Forks	2 hr

Nearby

Flash Flood Warnings in North Dakota, 2021 Every flash flood warning in 2021

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.