Alert archive / Iowa / Flash Flood Watches in 2008

Flash Flood Watch 18, NWS Des Moines, IA

July 26, 200842 counties in Iowa

NWS Des Moines, IA issued this flash flood watch at Jul 26, 2008, 4:22 AM CDT for 42 counties in Iowa. It took effect at Jul 27, 2008, 12:00 AM CDT. It was in force for .

The area

The counties it named.

The facts

Issued: Jul 26, 2008, 4:22 AM CDT (09:22 UTC)
In effect from: Jul 27, 2008, 12:00 AM CDT
Expired: Jul 26, 2008, 2:04 PM CDT
In force
Issued by: NWS Des Moines, IA
Flood severity: None

All 42 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Boone County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Clarke County, IA, Crawford County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Emmet County, IA, Greene County, IA, Guthrie County, IA, Hamilton County, IA, Hardin County, IA, Humboldt County, IA, Jasper County, IA, Kossuth County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Palo Alto County, IA, Pocahontas County, IA, Polk County, IA, Poweshiek County, IA, Ringgold County, IA, Sac County, IA, Story County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Wapello County, IA, Warren County, IA, Wayne County, IA, Webster County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 12 km from the middle of the area, began a volume at 09:21 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

Davenport, (KDVN), launched 00:00Z, 9.4 hours before the alert went out and 280 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: 676 J/kg
Mixed-layer CIN: -84 J/kg
Mixed-layer LCL: 861 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 87 m²/s²
0-3 km storm-relative helicity: 94 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 3.1

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 Des Moines, IA wrote its last area forecast discussion before this flash flood watch went out at Jul 26, 3:30 AM CDT, 52 minutes earlier.

Area forecast discussion, Jul 26, 3:30 AM CDT, 52 minutes before

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Hazardous weather outlook, Jul 25, 9:23 PM CDT, 6 hours 59 minutes before

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Nearby

Flash Flood Watches in Iowa, 2008 Every flash flood watch in 2008

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.