Alert archive / Wisconsin / Flash Flood Warnings in 2018

Flash Flood Warning 8, NWS Twin Cities, MN

August 24, 2018Pierce County, Saint Croix County, Wisconsin

NWS Twin Cities, MN issued this flash flood warning at Aug 24, 2018, 5:58 PM CDT for Pierce County, Saint Croix County, Wisconsin. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 24, 2018, 5:58 PM CDT (22:58 UTC)
Expired
Aug 24, 2018, 9:00 PM CDT
In force
3 hr
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon
Flood severity
None

Counties Pierce County, WI, Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 89 km from the middle of the area, began a volume at 23:00 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.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 11.0 hours before the alert went out and 92 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, Minneapolis, MN at 12:00Z on 2018-08-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 107 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, Minneapolis, MN at 12:00Z on 2018-08-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 150 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
107 J/kg
Mixed-layer CIN
-122 J/kg
Mixed-layer LCL
584 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
150 m²/s²
0-3 km storm-relative helicity
149 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

As transmitted.

040 
WGUS53 KMPX 242258
FFWMPX
WIC093-109-250200-
/O.NEW.KMPX.FF.W.0008.180824T2258Z-180825T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Twin Cities/Chanhassen MN
558 PM CDT FRI AUG 24 2018

The National Weather Service in The Twin Cities has issued a

* Flash Flood Warning for...
  Northwestern Pierce County in west central Wisconsin...
  Southeastern St. Croix County in west central Wisconsin...

* Until 900 PM CDT.

* At 556 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. 2 TO 4 inches of rain have 
  fallen across much of the area since this afternoon, with 
  localized amounts of more than 5 inches reported by spotters. 
  Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  River Falls, Hammond, Baldwin, Woodville, Beldenville, Hersey and
  Martel.

Additional rainfall amounts of an inch or two are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 4498 9219 4481 9240 4466 9265 4481 9272
      4489 9265 4492 9257 4504 9234 4505 9221

$$

The office that day

Everything else NWS Twin Cities, MN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 24, 5:22 PM CDTSpecial Weather StatementMPXSaint Croix83 min
Aug 24, 5:37 PM CDTSpecial Weather StatementMPXPierce83 min
Aug 24, 6:18 PM CDTSpecial Weather StatementMPXPierce87 min
Aug 24, 6:49 PM CDTSpecial Weather StatementMPXDunn116 min

Nearby

Flash Flood Warnings in Wisconsin, 2018Every flash flood warning in 2018

Sources

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