Alert archive / Missouri / Areal Flood Advisories in 2012

Areal Flood Advisory 25, NWS St. Louis, MO

August 31, 2012Audrain County, Missouri

NWS St. Louis, MO issued this areal flood advisory at Aug 31, 2012, 6:52 PM CDT for Audrain County, Missouri. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
Aug 31, 2012, 6:52 PM CDT (23:52 UTC)
Expired
Aug 31, 2012, 9:30 PM CDT
In force
3 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon

County Audrain County, MO

The radar

The St Louis radar (KLSX), 116 km from the middle of the area, began a volume at 23:54 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, 11.9 hours before the alert went out and 296 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-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2012-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 947 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2012-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -60 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
947 J/kg
Mixed-layer CIN
-143 J/kg
Mixed-layer LCL
1049 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
-60 m²/s²
0-3 km storm-relative helicity
-45 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.3

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 31, 2:48 PM CDTTornado WarningLSXSaint Charles, Saint Louis17 min
Aug 31, 5:34 PM CDTTornado WarningLSXLincoln, Saint Charles11 min
Aug 31, 2:44 PM CDTTornado WarningLSXGreene, Jersey, Pike31 min
Aug 31, 3:27 PM CDTTornado WarningLSXGreene, Pike48 min

Nearby

Areal Flood Advisories in Missouri, 2012Every areal flood advisory in 2012

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.