Alert archive / Minnesota / Flash Flood Warnings in 2009

Flash Flood Warning 4, NWS Twin Cities, MN

August 8, 20095 counties in Minnesota

NWS Twin Cities, MN issued this flash flood warning at Aug 8, 2009, 1:01 AM CDT for 5 counties in Minnesota. It was in force for 4 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 8, 2009, 1:01 AM CDT (06:01 UTC)
Expired
Aug 8, 2009, 5:00 AM CDT
In force
4 hr
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon
Flood severity
None

Counties Carver County, MN, Dakota County, MN, Hennepin County, MN, Ramsey County, MN, Washington County, MN

The radar

The Minneapolis radar (KMPX), 19 km from the middle of the area, began a volume at 06:01 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 00:00Z, 6.0 hours before the alert went out and 21 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 2009-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 2009-08-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 183 square meters per square second.19395878Sfc1 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
1 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
517 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
183 m²/s²
0-3 km storm-relative helicity
341 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

000 
WGUS53 KMPX 080601
FFWMPX
MNC019-037-053-123-163-081000-
/O.NEW.KMPX.FF.W.0004.090808T0601Z-090808T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
101 AM CDT SAT AUG 8 2009

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EASTERN CARVER COUNTY IN EAST CENTRAL MINNESOTA
  NORTHERN DAKOTA COUNTY IN EAST CENTRAL MINNESOTA
  SOUTHERN HENNEPIN COUNTY IN EAST CENTRAL MINNESOTA
  SOUTHERN RAMSEY COUNTY IN EAST CENTRAL MINNESOTA
  SOUTHERN WASHINGTON COUNTY IN EAST CENTRAL MINNESOTA

* UNTIL 500 AM CDT

* AT 1258 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE
  WARNED AREA...AND ESTIMATED THAT 2 INCHES OF RAIN HAS FALLEN SINCE
  MIDNIGHT ACROSS THE SOUTHERN TWIN CITIES METRO AREA.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  MINNEAPOLIS...ST PAUL...BAYPORT...BLOOMINGTON...CHANHASSEN...
  CHASKA...COTTAGE GROVE...DEEPHAVEN...EAGAN...EDEN
  PRAIRIE...EDINA...EXCELSIOR...FALCON HEIGHTS AND GOLDEN VALLEY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF 2 TO 3 ARE POSSIBLE IN
THE WARNED AREA IN THE NEXT 3 HOURS.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

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 4504 9377 4503 9276 4481 9277 4482 9377

$$

MPG
1 follow-up statement
000 
WGUS73 KMPX 080733
FFSMPX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
233 AM CDT SAT AUG 8 2009

MNC019-037-053-123-163-081000-
/O.CON.KMPX.FF.W.0004.000000T0000Z-090808T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON MN-HENNEPIN MN-RAMSEY MN-CARVER MN-DAKOTA MN-
233 AM CDT SAT AUG 8 2009

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR NORTHERN DAKOTA...
EASTERN CARVER...SOUTHERN RAMSEY...SOUTHERN HENNEPIN AND SOUTHERN
WASHINGTON COUNTIES UNTIL 500 AM CDT...

AT 225 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THAT HEAVY RAIN HAD TEMPORARILY MOVED SOUTH OF THE AREA BUT MORE 
THUNDERSTORMS WERE MOVING IN FROM THE WEST. THESE THUNDERSTORMS 
COULD PRODUCE ANOTHER 1 INCH...TO AS MUCH AS 2 INCHES OF RAIN 
THROUGH 5 AM.

A LINE OF THUNDERSTORMS WAS PRODUCING VERY HEAVY RAINFALL IN THE 
WARNED AREA. RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH 
FLOODING TO OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING 
INCLUDE...MINNEAPOLIS...ST 
PAUL...BAYPORT...BLOOMINGTON...CHANHASSEN...CHASKA...COTTAGE 
GROVE...CRYSTAL...DEEPHAVEN...EAGAN...EDEN 
PRAIRIE...EDINA...EXCELSIOR...FALCON HEIGHTS...GOLDEN 
VALLEY...HOPKINS...INDEPENDENCE...INVER GROVE HEIGHTS...LAKE 
ELMO...LILYDALE...LITTLE CANADA...LONG LAKE...MAPLE 
PLAIN...MAPLEWOOD...MEDINA AND MENDOTA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THERE HAVE BEEN NUMEROUS REPORTS OF STREET FLOODING IN EASTERN 
CARVER COUNTY. 

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

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.

&&

LAT...LON 4504 9377 4503 9276 4481 9277 4482 9377

$$
JPR

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 7, 10:39 PM CDTSpecial Weather StatementMPXSibley51 min
Aug 7, 11:04 PM CDTSpecial Weather StatementMPXRenville26 min
Aug 8, 12:24 AM CDTAreal Flood AdvisoryMPXAnoka, Carver, Dakota, Hennepin, McLeod, Ramsey and 3 more3 hr
Aug 8, 12:28 AM CDTAreal Flood AdvisoryMPXAnoka, Carver, Dakota, Hennepin, McLeod, Ramsey and 3 more3 hr
Aug 8, 1:48 AM CDTFlash Flood WarningMPXCarver, Dakota, Scott, Washington4 hr
Aug 8, 4:06 AM CDTFlash Flood WatchMPXAnoka, Carver, Chippewa, Dakota, Goodhue, Hennepin and 14 more19 hr
Aug 8, 4:11 AM CDTSevere Thunderstorm WarningMPXMeeker, Sherburne, Stearns, Wright38 min
Aug 8, 4:19 AM CDTHeat AdvisoryMPXBlue Earth, Brown, Carver, Dakota, Faribault, Freeborn and 14 more14 hr
Aug 8, 5:02 AM CDTAreal Flood AdvisoryMPXBenton, Mille Lacs, Sherburne, Stearns, Wright3 hr
Aug 8, 5:29 AM CDTSpecial Weather StatementMPXBenton61 min
Aug 8, 8:06 AM CDTSevere Thunderstorm WarningMPXRenville39 min
Aug 8, 9:32 AM CDTSpecial Weather StatementMPXHennepin, Ramsey43 min
Aug 8, 9:43 AM CDTFlash Flood WarningMPXAnoka, Hennepin, Wright3 hr
Aug 8, 3:46 PM CDTSevere Thunderstorm WarningMPXBrown, Redwood28 min

Nearby

Flash Flood Warnings in Minnesota, 2009Every flash flood warning in 2009

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.