Alert archive / Iowa / Flash Flood Watches in 2018

Flash Flood Watch 11, NWS Quad Cities, IA

October 7, 201821 counties in Iowa; 13 counties in Illinois; Clark County, Scotland County, Missouri

NWS Quad Cities, IA issued this flash flood watch at Oct 7, 2018, 2:44 PM CDT for 21 counties in Iowa; 13 counties in Illinois; Clark County, Scotland County, Missouri. It was in force for 70 hr.

The area

The counties it named.

The facts

Issued: Oct 7, 2018, 2:44 PM CDT (19:44 UTC)
Expired: Oct 10, 2018, 1:00 PM CDT
In force: 70 hr
Issued by: NWS Quad Cities, IA
Flood severity: None

All 36 counties

Benton County, IA, Buchanan County, IA, Cedar County, IA, Clinton County, IA, Delaware County, IA, Des Moines County, IA, Dubuque County, IA, Henry County, IA, Iowa County, IA, Jackson County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Van Buren County, IA, Washington County, IA, Bureau County, IL, Carroll County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, McDonough County, IL, Mercer County, IL, Putnam County, IL, Rock Island County, IL, Stephenson County, IL, Warren County, IL, Whiteside County, IL, Clark County, MO, Scotland County, MO

The radar

The Quad Cities radar (KDVN), 41 km from the middle of the area, began a volume at 19:44 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

Lincoln, IL (KILX), launched 12:00Z, 7.7 hours before the alert went out and 251 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: 470 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 119 m²/s²
0-3 km storm-relative helicity: 127 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 7, 12:59 PM CDT, 1 hour 45 minutes earlier.

Area forecast discussion, Oct 7, 12:59 PM CDT, 1 hour 45 minutes before

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Hazardous weather outlook, Oct 7, 4:57 AM CDT, 9 hours 47 minutes before

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In the hours before

Local storm report, Oct 7, 9:48 AM CDT, 4 hours 56 minutes before

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Local storm report, Oct 7, 10:33 AM CDT, 4 hours 11 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 6, 9:52 PM CDT	River Flood Watch	DVN	Benton, Linn	8 days
Oct 6, 9:52 PM CDT	River Flood Watch	DVN	Cedar, Johnson, Linn	35 hr
Oct 6, 9:59 PM CDT	Areal Flood Warning	DVN	Iowa	13 hr

Nearby

Flash Flood Watches in Iowa, 2018 Flash Flood Watches in Illinois, 2018 Flash Flood Watches in Missouri, 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.