Alert archive / Minnesota / Flash Flood Warnings in 2011

Flash Flood Warning 15, NWS Twin Cities, MN

August 16, 20114 counties in Minnesota

NWS Twin Cities, MN issued this flash flood warning at Aug 16, 2011, 8:41 PM CDT for 4 counties in Minnesota. It was in force for 3 hr. 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
Aug 16, 2011, 8:41 PM CDT (01:41 UTC)
Expired
Aug 16, 2011, 11:30 PM CDT
In force
3 hr
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon
Flood severity
None

Counties Anoka County, MN, Hennepin County, MN, Ramsey County, MN, Washington County, MN

The radar

The Minneapolis radar (KMPX), 57 km from the middle of the area, began a volume at 01:41 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 16, 9:45 PM CDTFLASH FLOOD1 Ene New Brighton, MNRAMP CLOSED FROM WESTBOUND 694 TO NORTHBOUND 35W PER MNDOT AND STATE PATROL.
Aug 16, 11:00 PM CDTHEAVY RAIN 3.215 Nw Roseville, MNHEAVY RAIN FELL DURING THE EVENING ON TUESDAY...AUGUST 16.

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

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 1.7 hours before the alert went out and 59 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 00:00Z on 2011-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 522 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 00:00Z on 2011-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 198 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
522 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
839 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
198 m²/s²
0-3 km storm-relative helicity
152 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.2

Open this sounding in Storm Lab

The text

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

280 
WGUS53 KMPX 170141
FFWMPX
MNC003-053-123-163-170430-
/O.NEW.KMPX.FF.W.0015.110817T0141Z-110817T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
841 PM CDT TUE AUG 16 2011

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHERN AND CENTRAL WASHINGTON COUNTY IN EAST CENTRAL MINNESOTA...
  EASTERN HENNEPIN COUNTY IN EAST CENTRAL MINNESOTA...
  RAMSEY COUNTY IN EAST CENTRAL MINNESOTA...
  EXTREME SOUTHERN ANOKA COUNTY IN EAST CENTRAL MINNESOTA...

* UNTIL 1130 PM CDT

* AT 838 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE      
  WARNED AREA. RAINFALL RATES OF 2 TO 3 INCHES PER HOUR WILL OCCUR   
  WITH THESE STORMS. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  MINNEAPOLIS...ST PAUL...ARDEN HILLS...BAYPORT...BROOKLYN CENTER...
  BROOKLYN PARK...CENTERVILLE...CIRCLE PINES...COLUMBIA HEIGHTS...
  CRYSTAL...FALCON HEIGHTS...FRIDLEY...GOLDEN VALLEY...HILLTOP...
  HUGO...LAKE ELMO...LAUDERDALE...LEXINGTON...LITTLE CANADA...
  MAHTOMEDI...MAPLEWOOD...MARINE ON ST CROIX...MOUNDS VIEW...NEW
  BRIGHTON...NORTH OAKS...NORTH ST PAUL...OAKDALE...ROBBINSDALE...
  ROSEVILLE AND SHOREVIEW.

AT 835 PM CDT...LAW ENFORCEMENT REPORTED STREET AND SMALL STREAM 
FLOODING IN BROOKLYN PARK. FLOODING WAS ALSO REPORTED NEAR NORTHTOWN 
SHOPPING CENTER ALONG THE BORDER OF BLAINE AND SPRING LAKE PARK. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. DO
NOT ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND TO
ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN
WATER BEGINS RISING.

&&

LAT...LON 4520 9277 4509 9277 4508 9280 4505 9280
      4503 9277 4493 9277 4490 9336 4512 9337

$$

Nearby

Flash Flood Warnings in Minnesota, 2011Every flash flood warning 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.