Alert archive / Missouri / Flood Watches in 2026

Flood Watch 12, NWS St. Louis, MO

August 14, 20264 counties in Missouri; Adams County, Brown County, Illinois

NWS St. Louis, MO issued this flood watch at Aug 14, 2026, 9:48 PM CDT for 4 counties in Missouri; Adams County, Brown County, Illinois. It took effect at Aug 15, 2026, 1:00 AM CDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued
Aug 14, 2026, 9:48 PM CDT (02:48 UTC)
In effect from
Aug 15, 2026, 1:00 AM CDT
Expired
Aug 15, 2026, 10:00 AM CDT
In force
9 hr
Issued by
NWS St. Louis, MO
Flood severity
None

Counties Adams County, IL, Brown County, IL, Knox County, MO, Lewis County, MO, Marion County, MO, Shelby County, MO

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 2.8 hours before the alert went out and 206 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, Davenport, at 00:00Z on 2026-08-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 130 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, Davenport, at 00:00Z on 2026-08-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 145 square meters per square second.193958Sfc1 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
130 J/kg
Mixed-layer CIN
-117 J/kg
Mixed-layer LCL
627 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
145 m²/s²
0-3 km storm-relative helicity
196 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

Nearby

Flood Watches in Missouri, 2026Flood Watches in Illinois, 2026Every flood watch in 2026

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.