Alert archive / South Dakota / Flash Flood Watches in 2010

Flash Flood Watch 8, NWS Sioux Falls, SD

July 22, 201018 counties in South Dakota; 11 counties in Iowa; 8 counties in Minnesota

NWS Sioux Falls, SD issued this flash flood watch at Jul 22, 2010, 2:59 PM CDT for 18 counties in South Dakota; 11 counties in Iowa; 8 counties in Minnesota. It took effect at Jul 23, 2010, 6:00 PM CDT. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued: Jul 22, 2010, 2:59 PM CDT (19:59 UTC)
In effect from: Jul 23, 2010, 6:00 PM CDT
Expired: Jul 24, 2010, 1:39 AM CDT
In force: 8 hr
Issued by: NWS Sioux Falls, SD
Flood severity: None

All 37 counties

Buena Vista County, IA, Cherokee County, IA, Clay County, IA, Dickinson County, IA, Ida County, IA, Lyon County, IA, O'Brien County, IA, Osceola County, IA, Plymouth County, IA, Sioux County, IA, Woodbury County, IA, Cottonwood County, MN, Jackson County, MN, Lincoln County, MN, Lyon County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Rock County, MN, Beadle County, SD, Bon Homme County, SD, Brookings County, SD, Clay County, SD, Davison County, SD, Hanson County, SD, Hutchinson County, SD, Kingsbury County, SD, Lake County, SD, Lincoln County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Sanborn County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 18 km from the middle of the area, began a volume at 20:02 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, 8.0 hours before the alert went out and 277 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: 76 J/kg
Mixed-layer CIN: -134 J/kg
Mixed-layer LCL: 723 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 92 m²/s²
0-3 km storm-relative helicity: 130 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Sioux Falls, SD wrote its last area forecast discussion before this flash flood watch went out at Jul 22, 11:31 AM CDT, 3 hours 28 minutes earlier.

Area forecast discussion, Jul 22, 11:31 AM CDT, 3 hours 28 minutes before

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Hazardous weather outlook, Jul 22, 11:40 AM CDT, 3 hours 19 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1140 AM CDT THU JUL 22 2010

SDZ038>040-050-052>071-MNZ071-072-080-081-089-090-097-098-
IAZ001>003-012>014-020>022-031-032-NEZ013-014-231200-
AURORA-BEADLE-BON HOMME-BROOKINGS-BRULE-BUENA VISTA IA-
CHARLES MIX-CHEROKEE IA-CLAY-CLAY IA-COTTONWOOD MN-DAKOTA NE-
DAVISON-DICKINSON IA-DIXON NE-DOUGLAS-GREGORY-HANSON-HUTCHINSON-
IDA IA-JACKSON MN-JERAULD-KINGSBURY-LAKE-LINCOLN-LINCOLN MN-
LYON IA-LYON MN-MCCOOK-MINER-MINNEHAHA-MOODY-MURRAY MN-NOBLES MN-
OBRIEN IA-OSCEOLA IA-PIPESTONE MN-PLYMOUTH IA-ROCK MN-SANBORN-
SIOUX IA-TURNER-UNION-WOODBURY IA-YANKTON-
1140 AM CDT THU JUL 22 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST SOUTH DAKOTA...
SOUTHWEST MINNESOTA...NORTHWEST IOWA...AND NORTHEAST NEBRASKA.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS...
THERE IS A CHANCE FOR STORMS TO REDEVELOP VERY LATE THIS
AFTERNOON INTO THE EVENING HOURS FROM SOUTH CENTRAL SOUTH DAKOTA
TOWARD NORTHEAST NEBRASKA...AND THEN A BIT LATER INTO THE NIGHT
THROUGH NORTHWEST IOWA AND SOUTHWEST MINNESOTA. WIDESPREAD SEVERE
WEATHER IS NOT EXPECTED...HOWEVER ISOLATED STORMS MAY PRODUCE
DAMAGING WINDS TO AROUND 50 MPH AND DIME SIZE HAIL.

FLOODING...
HEAVY RAINFALL FROM OVERNIGHT LAST NIGHT HAS PRODUCED RIVER
FLOODING FOR THE VERMILLION...BIG SIOUX...AND LITTLE SIOUX
RIVERS...AND FLOODING CONTINUES ALONG THE JAMES RIVER.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

A POTENT SEVERE WEATHER SETUP LOOKS TO EXIST FROM FRIDAY
AFTERNOON INTO FRIDAY EVENING. STORMS SHOULD ERUPT RAPIDLY IN THE
MID TO LATE AFTERNOON HOURS ACROSS CENTRAL SOUTH DAKOTA...AND
EXPAND ALONG A FRONTAL BOUNDARY SITTING NEAR INTERSTATE 90.
THERE WILL BE A THREAT FOR TORNADOES THROUGH SHORTLY AFTER
SUNSET...AND STORMS WILL BE CAPABLE OF PRODUCING WIND GUSTS TO 80
MPH AND HAIL TO HEN EGG SIZE. THE SEVERE THREAT WILL DROP OFF
SOMEWHAT AFTER SUNSET AS STORMS SPREAD INTO NORTHWEST IOWA...WITH
A CONTINUED DAMAGING WIND THREAT AND HAIL TO HALF DOLLAR SIZE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL BE POSSIBLE AFTER 6 PM CDT.

&&

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT
WWW.WEATHER.GOV/SIOUXFALLS. THIS INCLUDES THE GRAPHICAL HAZARDOUS
WEATHER OUTLOOK.

In the hours before

Local storm report, Jul 22, 9:25 AM CDT, 5 hours 34 minutes before

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Local storm report, Jul 22, 10:01 AM CDT, 4 hours 58 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1001 AM CDT THU JUL 22 2010

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1000 AM     HEAVY RAIN       LAKE PARK               43.45N 95.32W
07/22/2010  E3.75 INCH       DICKINSON          IA   PUBLIC

1000 AM     HEAVY RAIN       5 N MELVIN              43.36N 95.61W
07/22/2010  M6.63 INCH       OSCEOLA            IA   PUBLIC

&&

PS

Local storm report, Jul 22, 10:50 AM CDT, 4 hours 9 minutes before

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Local storm report, Jul 22, 12:34 PM CDT, 2 hours 25 minutes before

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Local storm report, Jul 22, 1:49 PM CDT, 1 hour 10 minutes before

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The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 21, 7:15 PM CDT	Severe Thunderstorm Warning	FSD	Jerauld	45 min
Jul 21, 7:23 PM CDT	Severe Thunderstorm Warning	FSD	Aurora, Brule	37 min
Jul 21, 7:47 PM CDT	Severe Thunderstorm Warning	FSD	Jerauld, Sanborn	43 min
Jul 21, 7:52 PM CDT	Severe Thunderstorm Warning	FSD	Aurora, Brule, Charles Mix, Douglas	38 min
Jul 21, 7:54 PM CDT	Flash Flood Warning	FSD	Davison, Hanson, Sanborn	6 hr
Jul 21, 9:48 PM CDT	Flash Flood Warning	FSD	Lincoln, Minnehaha	6 hr
Jul 21, 10:53 PM CDT	Flash Flood Warning	FSD	Lincoln, Minnehaha	6 hr
Jul 21, 11:25 PM CDT	Flash Flood Warning	FSD	Clay, Lincoln, Turner, Union, Yankton	7 hr
Jul 22, 2:08 AM CDT	Flash Flood Warning	FSD	Union	4 hr
Jul 22, 2:48 AM CDT	River Flood Warning	FSD	Turner	56 hr
Jul 22, 10:20 AM CDT	River Flood Warning	FSD	Lincoln, Union	6 days
Jul 22, 10:20 AM CDT	River Flood Warning	FSD	Union	6 days
Jul 22, 10:20 AM CDT	River Flood Warning	FSD	Turner	11 hr
Jul 22, 10:20 AM CDT	River Flood Warning	FSD	Turner	5 days
Jul 22, 10:20 AM CDT	River Flood Warning	FSD	Clay	23 days
Jul 22, 10:20 AM CDT	River Flood Warning	FSD	Clay	11 hr
Jul 22, 5:08 PM CDT	River Flood Warning	FSD	Bon Homme, Charles Mix	17 hr
Jul 22, 5:08 PM CDT	River Flood Warning	FSD	Bon Homme	29 hr
Jul 22, 5:08 PM CDT	River Flood Warning	FSD	Bon Homme	3 days
Jul 21, 11:57 PM CDT	Flash Flood Warning	FSD	Clay, Dickinson, Lyon, O'Brien, Osceola	5 hr
Jul 22, 12:29 AM CDT	Severe Thunderstorm Warning	FSD	Cherokee, O'Brien, Plymouth, Sioux	46 min
Jul 22, 1:03 AM CDT	Flash Flood Warning	FSD	Buena Vista, Cherokee, Clay, O'Brien	6 hr
Jul 22, 1:39 AM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Cherokee, Clay, Ida	51 min
Jul 22, 10:39 AM CDT	River Flood Warning	FSD	O'Brien	26 hr
Jul 22, 10:39 AM CDT	River Flood Warning	FSD	Sioux	3 days
Jul 22, 10:39 AM CDT	River Flood Warning	FSD	Clay, Dickinson	10 days
Jul 22, 10:39 AM CDT	River Flood Warning	FSD	Clay	10 days
Jul 22, 10:39 AM CDT	River Flood Warning	FSD	Buena Vista, Clay	13 days
Jul 22, 10:39 AM CDT	River Flood Warning	FSD	Monona, Woodbury	10 hr
Jul 22, 2:16 PM CDT	River Flood Warning	FSD	Cherokee	7 hr

Nearby

Flash Flood Watches in South Dakota, 2010 Flash Flood Watches in Iowa, 2010 Flash Flood Watches in Minnesota, 2010 Every flash flood watch in 2010

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.