Alert archive / Michigan / Flash Flood Warnings in 2011

Flash Flood Warning 4, NWS Detroit, MI

June 21, 2011Genesee County, Shiawassee County, Michigan

NWS Detroit, MI issued this flash flood warning at Jun 21, 2011, 10:27 PM EDT for Genesee County, Shiawassee County, Michigan. It was in force for 5 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: Jun 21, 2011, 10:27 PM EDT (02:27 UTC)
Expired: Jun 22, 2011, 2:59 AM EDT
In force: 5 hr
Issued by: NWS Detroit, MI
Area: Storm-based polygon
Flood severity: None

Counties Genesee County, MI, Shiawassee County, MI

The radar

The Detroit radar (KDTX), 45 km from the middle of the area, began a volume at 02:28 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	Remark
Jun 21, 10:30 PM EDT	HEAVY RAIN 1.4	Corunna, MI	24 HOUR RAINFALL TOTAL.
Jun 21, 11:00 PM EDT	FLASH FLOOD	3 Sw Flint, MI	A COUPLE FEET OF WATER COVERING NORTHBOUND AND SOUTHBOUND I-75 BETWEEN CORUNNA ROAD AND I-69

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

The nearest sounding before it

Detroit, MI (KDTX), launched 00:00Z, 2.5 hours before the alert went out and 46 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: 3352 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 668 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 153 m²/s²
0-3 km storm-relative helicity: 180 m²/s²
Significant tornado parameter: 2.9
Supercell composite: 14.4

Open this sounding in Storm Lab

The text

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

106 
WGUS53 KDTX 220227
FFWDTX
MIC049-155-220830-
/O.NEW.KDTX.FF.W.0004.110622T0227Z-110622T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1027 PM EDT TUE JUN 21 2011

THE NATIONAL WEATHER SERVICE IN DETROIT/PONTIAC HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  GENESEE COUNTY IN SOUTHEAST MICHIGAN...
  SHIAWASSEE COUNTY IN SOUTHEAST MICHIGAN...

* UNTIL 430 AM EDT WEDNESDAY

* AT 1023 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. 
  RADAR ESTIMATES UP TO 2 INCHES WERE INDICATED IN SHIAWASSEE COUNTY 
  SINCE ABOUT 9 PM THIS EVENING. ADDITIONAL RAINFALL UP TO 2 INCHES 
  IS EXPECTED BEFORE THE STORMS MOVE OUT OF THE AREA. SIMILAR RAINFALL 
  TOTALS ARE EXPECTED IN GENESEE COUNTY...ESPECIALLY IN THE FLINT
  VICINITY. 
  
* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  CLIO...DAVISON...DURAND...FENTON...FLINT...FLUSHING...GRAND
  BLANC...LAINGSBURG...NEW LOTHROP...OWOSSO...PERRY...BANCROFT...
  BURTON...BYRON...CORUNNA...GAINES...GOODRICH...HENDERSON...
  LENNON...LINDEN...MONTROSE...MORRICE...MOUNT MORRIS...OTISVILLE AND
  SWARTZ CREEK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...
COUNTRY ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND
OTHER LOW LYING AREAS ARE SUBJECT TO FLOODING.

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 4313 8393 4322 8393 4322 8346 4287 8345
      4287 8369 4279 8369 4278 8373 4278 8436
      4313 8436

$$

BT

3 follow-up statements

831 
WGUS73 KDTX 220335
FFSDTX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1135 PM EDT TUE JUN 21 2011

MIC049-155-220830-
/O.CON.KDTX.FF.W.0004.000000T0000Z-110622T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GENESEE MI-SHIAWASSEE MI-
1135 PM EDT TUE JUN 21 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SHIAWASSEE AND GENESEE
COUNTIES UNTIL 430 AM EDT...

AT 1127 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. RADAR 
RAINFALL ESTIMATES AND SPOTTER REPORTS INDICATE 1 TO 2 INCHES OF RAIN 
FELL ACROSS THE WARNED AREA IN ABOUT ONE HOUR. ADDITIONAL RAINFALL 
AROUND HALF AN INCH WILL BE POSSIBLE ACROSS NORTHERN GENESEE COUNTY 
OVER THE NEXT HOUR.

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLASH FLOODING INCLUDE...
CLIO...DAVISON...DURAND...FENTON...FLINT...FLUSHING...GRAND BLANC...
LAINGSBURG...NEW LOTHROP...OWOSSO...PERRY...BANCROFT...BURTON...
BYRON...CORUNNA...GAINES...GOODRICH...HENDERSON...LENNON...LINDEN...
MONTROSE...MORRICE...MOUNT MORRIS...OTISVILLE AND SWARTZ CREEK.

THERE WAS ALSO A REPORT OF FLOODING IN THE FLINT AREA WITH TWO FEET 
OF WATER COVERING I-75 BETWEEN CORUNNA ROAD AND I-69.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLOODING OF SMALL CREEKS
AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY ROADS
AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW LYING
AREAS ARE ALSO SUBJECT TO FLOODING.

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.

&&

LAT...LON 4313 8393 4322 8393 4322 8346 4287 8345
      4287 8369 4279 8369 4278 8373 4278 8436
      4313 8436

$$

MR

147 
WGUS73 KDTX 220516
FFSDTX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
116 AM EDT WED JUN 22 2011

MIC049-155-220830-
/O.CON.KDTX.FF.W.0004.000000T0000Z-110622T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GENESEE MI-SHIAWASSEE MI-
116 AM EDT WED JUN 22 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SHIAWASSEE AND GENESEE
COUNTIES UNTIL 430 AM EDT...

AT 110 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS DIMINISHING OVER THE REGION AS THE PATTERN OF HEAVY
RAINFALL MOVES TOWARD THE NORTH. A SHOWER OR THUNDERSTORM WITH A 
BRIEF HEAVY DOWNPOUR REMAINS POSSIBLE BUT IMPROVEMENT IN FLOODING 
CONDITIONS IS EXPECTED DURING THE EARLY MORNING HOURS. 

IN THE MEANTIME...RUNOFF FROM EARLIER EXCESSIVE RAINFALL WILL NEED 
TIME TO RECEDE. LOCATIONS WITH THE HEAVIEST RAINFALL TOTALS AND 
CONTINUED FLOODING CONCERNS INCLUDE...CLIO...DURAND...FLINT... 
FLUSHING... LAINGSBURG...NEW LOTHROP...OWOSSO...PERRY... 
BANCROFT...BYRON...CORUNNA...HENDERSON...LENNON...MONTROSE...
MORRICE...MOUNT MORRIS...OTISVILLE AND SWARTZ CREEK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLOODING OF SMALL CREEKS
AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY ROADS
AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW LYING
AREAS ARE ALSO SUBJECT TO FLOODING.

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.

&&

LAT...LON 4313 8393 4322 8393 4322 8346 4287 8345
      4287 8369 4279 8369 4278 8373 4278 8436
      4313 8436

$$

BT

013 
WGUS73 KDTX 220659
FFSDTX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
259 AM EDT WED JUN 22 2011

MIC049-155-220706-
/O.CAN.KDTX.FF.W.0004.000000T0000Z-110622T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GENESEE MI-SHIAWASSEE MI-
259 AM EDT WED JUN 22 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SHIAWASSEE AND
GENESEE COUNTIES IS CANCELLED...

SCATTERED SHOWERS LINGERED OVER SHIAWASSEE AND GENESEE COUNTIES 
EARLY THIS MORNING. HOWEVER...HEAVY RAINFALL ENDED SHORTLY AFTER 100 
AM THIS MORNING...GIVING STREAMS AND CREEKS A CHANCE TO RECEDE 
ENOUGH TO EASE THE FLOODING HAZARD...AND ALLOW CANCELLATION OF THE 
WARNING. 

LAT...LON 4313 8393 4322 8393 4322 8346 4287 8345
      4287 8369 4279 8369 4278 8373 4278 8436
      4313 8436

$$

BT

The office that day

Everything else NWS Detroit, MI issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 21, 8:05 PM EDT	Severe Thunderstorm Warning	DTX	Monroe	55 min
Jun 21, 8:06 PM EDT	Special Marine Warning	DTX		83 min
Jun 21, 8:29 PM EDT	Severe Thunderstorm Warning	DTX	Bay, Midland, Saginaw	76 min
Jun 21, 8:36 PM EDT	Severe Thunderstorm Warning	DTX	Lenawee	22 min
Jun 21, 9:02 PM EDT	Flash Flood Warning	DTX	Bay, Midland, Saginaw	6 hr
Jun 21, 9:04 PM EDT	Severe Thunderstorm Warning	DTX	Shiawassee	56 min
Jun 21, 9:23 PM EDT	Special Marine Warning	DTX		97 min
Jun 21, 9:31 PM EDT	Tornado Warning	DTX	Genesee, Saginaw	33 min
Jun 21, 9:44 PM EDT	Severe Thunderstorm Warning	DTX	Bay, Genesee, Saginaw, Tuscola	76 min
Jun 21, 9:59 PM EDT	Severe Thunderstorm Warning	DTX	Shiawassee	15 min
Jun 21, 10:27 PM EDT	Special Marine Warning	DTX		45 min
Jun 21, 10:40 PM EDT	Areal Flood Advisory	DTX	Macomb, Saint Clair	4 hr
Jun 21, 10:43 PM EDT	Severe Thunderstorm Warning	DTX	Lapeer, Tuscola	42 min
Jun 21, 10:46 PM EDT	Severe Thunderstorm Warning	DTX	Saint Clair	49 min
Jun 21, 10:48 PM EDT	Special Marine Warning	DTX		87 min
Jun 22, 4:22 AM EDT	Flash Flood Watch	DTX	Bay, Genesee, Huron, Lapeer, Midland, Saginaw and 4 more	15 hr
Jun 22, 1:48 PM EDT	Severe Thunderstorm Warning	DTX	Saginaw, Shiawassee	72 min
Jun 22, 1:50 PM EDT	Severe Thunderstorm Warning	DTX	Bay, Midland	85 min
Jun 22, 1:56 PM EDT	Special Marine Warning	DTX		109 min
Jun 22, 2:06 PM EDT	Severe Thunderstorm Warning	DTX	Shiawassee	69 min
Jun 22, 2:09 PM EDT	Special Marine Warning	DTX		96 min
Jun 22, 2:15 PM EDT	Severe Thunderstorm Warning	DTX	Livingston, Washtenaw	46 min
Jun 22, 2:36 PM EDT	Severe Thunderstorm Warning	DTX	Tuscola	69 min
Jun 22, 2:41 PM EDT	Severe Thunderstorm Warning	DTX	Genesee	59 min
Jun 22, 3:12 PM EDT	Severe Thunderstorm Warning	DTX	Oakland	63 min
Jun 22, 3:15 PM EDT	Severe Thunderstorm Warning	DTX	Huron	90 min
Jun 22, 3:22 PM EDT	Severe Thunderstorm Warning	DTX	Lapeer, Tuscola	52 min
Jun 22, 3:42 PM EDT	Special Marine Warning	DTX		93 min
Jun 22, 3:42 PM EDT	Severe Thunderstorm Warning	DTX	Macomb, Saint Clair	93 min
Jun 22, 3:53 PM EDT	Severe Thunderstorm Warning	DTX	Tuscola	43 min
Jun 22, 4:00 PM EDT	Severe Thunderstorm Warning	DTX	Huron, Sanilac	45 min
Jun 22, 4:07 PM EDT	Special Marine Warning	DTX		98 min
Jun 22, 4:12 PM EDT	Tornado Warning	DTX	Macomb, Saint Clair	63 min
Jun 22, 4:44 PM EDT	Severe Thunderstorm Warning	DTX	Bay, Genesee, Saginaw	46 min
Jun 22, 4:45 PM EDT	Severe Thunderstorm Warning	DTX	Huron, Sanilac	30 min
Jun 22, 4:47 PM EDT	Special Marine Warning	DTX		58 min
Jun 22, 4:54 PM EDT	Severe Thunderstorm Warning	DTX	Lapeer, Tuscola	66 min
Jun 22, 5:15 PM EDT	Tornado Warning	DTX	Saint Clair	15 min
Jun 22, 5:22 PM EDT	Special Marine Warning	DTX		83 min
Jun 22, 5:30 PM EDT	Severe Thunderstorm Warning	DTX	Huron, Sanilac	75 min
Jun 22, 5:40 PM EDT	Severe Thunderstorm Warning	DTX	Lapeer, Macomb, Oakland, Saint Clair	80 min
Jun 22, 5:43 PM EDT	Special Marine Warning	DTX		107 min
Jun 22, 5:53 PM EDT	Special Marine Warning	DTX		97 min
Jun 22, 6:35 PM EDT	Special Marine Warning	DTX		55 min

Nearby

Flash Flood Warnings in Michigan, 2011 Every 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.