Alert archive / Missouri / Areal Flood Warnings in 2017

Areal Flood Warning 20, NWS St. Louis, MO

May 2, 20174 counties in Missouri; Calhoun County, Illinois

NWS St. Louis, MO issued this areal flood warning at May 2, 2017, 10:55 AM CDT for 4 counties in Missouri; Calhoun County, Illinois. It was in force for 3 days. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: May 2, 2017, 10:55 AM CDT (15:55 UTC)
Expired: May 5, 2017, 11:00 AM CDT
In force: 3 days
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Flood severity: None

Counties Calhoun County, IL, Gasconade County, MO, Lincoln County, MO, Montgomery County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 45 km from the middle of the area, began a volume at 15:59 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, 3.9 hours before the alert went out and 261 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: 1243 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 102 m²/s²
0-3 km storm-relative helicity: 98 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 areal flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS St. Louis, MO wrote its last area forecast discussion before this areal flood warning went out at May 2, 6:57 AM CDT, 3 hours 58 minutes earlier.

Area forecast discussion, May 2, 6:57 AM CDT, 3 hours 58 minutes before

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Hazardous weather outlook, May 2, 4:13 AM CDT, 6 hours 42 minutes before

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The office that day

Everything else NWS St. Louis, MO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 2, 4:07 AM CDT	Flash Flood Watch	LSX	Audrain, Boone, Callaway, Cole, Crawford, Franklin and 17 more	64 hr
May 2, 9:28 AM CDT	Areal Flood Warning	LSX	Boone, Callaway, Cole, Moniteau, Osage	3 days
May 2, 4:43 PM CDT	Areal Flood Warning	LSX	Crawford, Iron, Madison, Reynolds, Sainte Genevieve, Saint Francois and 1 more	3 days
May 2, 10:03 AM CDT	Areal Flood Warning	LSX	Bond, Fayette, Greene, Jersey, Macoupin, Montgomery	72 hr

Nearby

Areal Flood Warnings in Missouri, 2017 Areal Flood Warnings in Illinois, 2017 Every areal flood warning in 2017

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.