Alert archive / North Dakota / Flash Flood Warnings in 2021

Flash Flood Warning 7, NWS Bismarck, ND

August 30, 2021Oliver County, North Dakota

NWS Bismarck, ND issued this flash flood warning at Aug 30, 2021, 11:46 AM CDT for Oliver County, North Dakota. It was in force for 3 hr. 1 report 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
Aug 30, 2021, 11:46 AM CDT (16:46 UTC)
Expired
Aug 30, 2021, 2:45 PM CDT
In force
3 hr
Issued by
NWS Bismarck, ND
Area
Storm-based polygon
Flood severity
None

County Oliver County, ND

The radar

The Bismarck radar (KBIS), 80 km from the middle of the area, began a volume at 16:49 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
Aug 30, 12:15 PM CDTHEAVY RAIN 3.69 W Hannover, NDRELAYED THROUGH BROADCAST MEDIA.

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, 4.8 hours before the alert went out and 84 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 2021-08-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 8 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Bismarck Municip, ND at 12:00Z on 2021-08-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 93 square meters per square second.193958Sfc1 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
8 J/kg
Mixed-layer CIN
-262 J/kg
Mixed-layer LCL
1949 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
93 m²/s²
0-3 km storm-relative helicity
131 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

417 
WGUS53 KBIS 301646
FFWBIS
NDC065-301945-
/O.NEW.KBIS.FF.W.0007.210830T1646Z-210830T1945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Bismarck ND
1146 AM CDT Mon Aug 30 2021

The National Weather Service in Bismarck has issued a

* Flash Flood Warning for...
  Northwestern Oliver County in south central North Dakota...

* Until 245 PM CDT.

* At 1145 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Up to four inches of rain has 
  fallen. Flash flooding is ongoing or expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

  IMPACT...Flooding of small creeks and streams, urban areas, 
           highways, streets and underpasses as well as other 
           drainage and low lying areas.

* Flash flooding will remain over mainly rural areas of northwestern
  Oliver County.

Additional rainfall amounts of up to two inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

&&

LAT...LON 4724 10150 4709 10157 4714 10176 4724 10176

FLASH FLOOD...RADAR INDICATED

$$

SCHILD
1 follow-up statement
724 
WGUS73 KBIS 301816
FFSBIS

Flash Flood Statement
National Weather Service Bismarck ND
116 PM CDT Mon Aug 30 2021

NDC065-301945-
/O.CON.KBIS.FF.W.0007.000000T0000Z-210830T1945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Oliver ND-
116 PM CDT Mon Aug 30 2021

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 245 PM CDT FOR
NORTHWESTERN OLIVER COUNTY...

At 114 PM CDT, Doppler radar indicated that over five inches of rain 
has fallen over the warned area. Flash flooding is ongoing or 
expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar indicated.

IMPACT...Flooding of small creeks and streams, urban areas, 
         highways, streets and underpasses as well as other drainage 
         and low lying areas.

Flash flooding will remain over mainly rural areas of northwestern
Oliver County.

Additional rainfall amounts of up to two inches are possible as 
additional thunderstorms move over the area this afternoon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

Please report flooding to your local law enforcement agency when you
can do so safely.

&&

LAT...LON 4724 10150 4709 10157 4714 10176 4724 10176

FLASH FLOOD...RADAR INDICATED

$$

SCHILD

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 30, 10:51 AM CDTSpecial Weather StatementBISOliver24 min
Aug 30, 10:54 AM CDTSevere Thunderstorm WarningBISOliver36 min
Aug 30, 11:28 AM CDTSevere Thunderstorm Warning Considerable damage threatBISOliver47 min
Aug 30, 11:33 AM CDTAreal Flood AdvisoryBISOliver3 hr
Aug 30, 12:13 PM CDTSevere Thunderstorm WarningBISMorton, Oliver47 min
Aug 30, 12:58 PM CDTSevere Thunderstorm WarningBISMorton, Oliver47 min
Aug 30, 1:02 PM CDTSevere Thunderstorm WarningBISMercer, Oliver43 min
Aug 30, 1:42 PM CDTSevere Thunderstorm Warning Considerable damage threatBISMorton, Oliver63 min
Aug 30, 1:44 PM CDTSevere Thunderstorm WarningBISMercer, Oliver61 min
Aug 30, 2:17 PM CDTSevere Thunderstorm Warning Destructive damage threatBISMorton58 min
Aug 30, 3:15 PM CDTSevere Thunderstorm Warning Considerable damage threatBISMorton60 min
Aug 30, 3:48 PM CDTSevere Thunderstorm WarningBISMcLean42 min
Aug 30, 4:16 PM CDTSevere Thunderstorm Warning Considerable damage threatBISMorton59 min
Aug 30, 4:32 PM CDTSevere Thunderstorm WarningBISHettinger58 min
Aug 30, 4:43 PM CDTSevere Thunderstorm WarningBISGrant, Morton47 min
Aug 30, 4:46 PM CDTAreal Flood AdvisoryBISMorton3 hr
Aug 30, 5:00 PM CDTSevere Thunderstorm Warning Considerable damage threatBISGrant, Morton60 min
Aug 30, 5:28 PM CDTSevere Thunderstorm WarningBISMercer, Oliver47 min
Aug 30, 5:29 PM CDTSevere Thunderstorm Warning Destructive damage threatBISAdams, Hettinger61 min
Aug 30, 5:43 PM CDTSevere Thunderstorm WarningBISMcLean, Mercer47 min
Aug 30, 5:54 PM CDTSevere Thunderstorm WarningBISGrant, Morton38 min
Aug 30, 6:02 PM CDTSevere Thunderstorm Warning Destructive damage threatBISGrant, Morton, Sioux58 min
Aug 30, 6:30 PM CDTSevere Thunderstorm Warning Considerable damage threatBISAdams60 min
Aug 30, 6:49 PM CDTSevere Thunderstorm WarningBISEmmons, Grant, Morton, Sioux35 min

Nearby

Flash Flood Warnings in North Dakota, 2021Every 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.