Alert archive / Iowa / Flash Flood Watches in 2018

Flash Flood Watch 10, NWS Quad Cities, IA

October 4, 201816 counties in Iowa; 9 counties in Illinois

NWS Quad Cities, IA issued this flash flood watch at Oct 4, 2018, 1:18 PM CDT for 16 counties in Iowa; 9 counties in Illinois. It took effect at Oct 5, 2018, 7:00 PM CDT. It was in force for 18 hr.

The area

The counties it named.

The facts

Issued: Oct 4, 2018, 1:18 PM CDT (18:18 UTC)
In effect from: Oct 5, 2018, 7:00 PM CDT
Expired: Oct 6, 2018, 1:00 PM CDT
In force: 18 hr
Issued by: NWS Quad Cities, IA
Flood severity: None

All 25 counties

Benton County, IA, Buchanan County, IA, Cedar County, IA, Clinton County, IA, Delaware County, IA, Dubuque County, IA, Iowa County, IA, Jackson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Linn County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Washington County, IA, Bureau County, IL, Carroll County, IL, Henry County, IL, Jo Daviess County, IL, Mercer County, IL, Putnam County, IL, Rock Island County, IL, Stephenson County, IL, Whiteside County, IL

The radar

The Quad Cities radar (KDVN), 32 km from the middle of the area, began a volume at 18:21 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 12:00Z, 6.3 hours before the alert went out and 37 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1204 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 7 m²/s²
0-3 km storm-relative helicity: 178 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 Quad Cities, IA wrote its last area forecast discussion before this flash flood watch went out at Oct 4, 12:30 PM CDT, 48 minutes earlier.

Area forecast discussion, Oct 4, 12:30 PM CDT, 48 minutes before

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Hazardous weather outlook, Oct 4, 4:48 AM CDT, 8 hours 30 minutes before

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The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 3, 9:06 PM CDT	Special Weather Statement	DVN	Benton, Buchanan, Delaware, Dubuque, Jones, Linn	54 min
Oct 3, 9:40 PM CDT	Severe Thunderstorm Warning	DVN	Dubuque, Jackson	50 min
Oct 3, 9:46 PM CDT	Special Weather Statement	DVN	Iowa, Johnson	74 min
Oct 3, 10:18 PM CDT	Special Weather Statement	DVN	Cedar, Clinton, Jackson, Muscatine, Scott	72 min
Oct 4, 9:29 AM CDT	River Flood Warning	DVN	Johnson, Louisa, Washington	12 days
Oct 4, 11:14 AM CDT	River Flood Warning	DVN	Lee	23 days
Oct 3, 10:28 PM CDT	Special Weather Statement	DVN	Jo Daviess, Stephenson	47 min
Oct 3, 11:35 PM CDT	Special Weather Statement	DVN	Bureau, Henry, Whiteside	25 min
Oct 4, 12:00 AM CDT	Special Weather Statement	DVN	Bureau, Putnam	45 min
Oct 4, 10:10 AM CDT	River Flood Warning	DVN	Henry, Rock Island	20 days

Nearby

Flash Flood Watches in Iowa, 2018 Flash Flood Watches in Illinois, 2018 Every flash flood watch in 2018

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.