Alert archive / Missouri / Flash Flood Warnings in 2020
Flash Flood Warning 45, NWS St. Louis, MO
NWS St. Louis, MO issued this flash flood warning at Jul 30, 2020, 6:49 AM CDT for Saint Charles County, Saint Louis County, City of Saint Louis, Missouri; Madison County, Illinois. It was in force for 5 hr. 3 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Jul 30, 2020, 6:49 AM CDT (11:49 UTC)
- Expired
- Jul 30, 2020, 12:16 PM CDT
- In force
- 5 hr
- Issued by
- NWS St. Louis, MO
- Area
- Storm-based polygon
- Flood severity
- None
Counties Madison County, IL, City of Saint Louis, MO, Saint Charles County, MO, Saint Louis County, MO
The radar
The St Louis radar (KLSX), 23 km from the middle of the area, began a volume at 11:49 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 30, 6:54 AM CDT | FLOOD | 2 N Bridgeton, MO | KMOV REPORTER SHARED A POST OF FLOODING THAT WAS OCCURRING ON AUBOCHON ROAD. TWO VEHICLES WERE STRANDED BUT DRIVERS WERE NOT HARMED. |
| Jul 30, 9:05 AM CDT | HEAVY RAIN 2.48 | 2 Sw Saint Ann, MO | 24 HOUR RAINFALL TOTAL OBSERVED AT THE KTVI-TV STUDIOS. |
| Jul 30, 9:34 AM CDT | HEAVY RAIN 2.9 | 1 Ne Saint Peters, MO | STORM TOTAL SUBMITTED BY THE PUBLIC. REPORT RELAYED BY KTVI-TV. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Lincoln, IL (KILX), launched 00:00Z, 11.8 hours before the alert went out and 226 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.
- Mixed-layer CAPE
- 348 J/kg
- Mixed-layer CIN
- -66 J/kg
- Mixed-layer LCL
- 1581 m above ground
- 0-6 km bulk shear
- 8 kt
- 0-1 km storm-relative helicity
- 4 m²/s²
- 0-3 km storm-relative helicity
- 40 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
465
WGUS53 KLSX 301149
FFWLSX
ILC119-MOC183-189-510-301745-
/O.NEW.KLSX.FF.W.0045.200730T1149Z-200730T1745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
649 AM CDT Thu Jul 30 2020
The National Weather Service in St Louis has issued a
* Flash Flood Warning for...
Southwestern Madison County in southwestern Illinois...
St. Louis City in east central Missouri...
Northeastern St. Charles County in east central Missouri...
St. Louis County in east central Missouri...
* Until 1245 PM CDT.
* At 648 AM CDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. 1 to 2 inches of rain have
fallen between 5:45 and 6:45 AM CDT. Flash flooding is ongoing or
expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar indicated.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other
drainage and low lying areas.
* Some locations that will experience flooding include...
St. Louis, O'Fallon, St. Charles, St. Peters, Florissant,
Chesterfield, Wildwood, University City, Ballwin, Kirkwood,
Maryland Heights, Hazelwood, Webster Groves, Ferguson, Arnold,
Manchester, Creve Coeur, Overland, Clayton and Cahokia.
This also includes Scott Joplin Historic Site, Route 66 State Park,
Castlewood State Park, Confluence State Park, and First Missouri
State Capitol Historic Site.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.
Please report flooding to your local law enforcement agency when you
can do so safely.
&&
LAT...LON 3867 9019 3861 9018 3854 9025 3843 9031
3844 9034 3846 9034 3845 9041 3848 9042
3849 9040 3850 9041 3850 9061 3878 9075
3889 9074 3891 9065 3888 9061 3887 9056
3891 9050 3895 9048 3897 9041 3884 9010
FLASH FLOOD...RADAR INDICATED
$$
TES1 follow-up statement
558
WGUS73 KLSX 301716
FFSLSX
Flash Flood Statement
National Weather Service St Louis MO
1216 PM CDT Thu Jul 30 2020
ILC119-MOC183-189-510-301725-
/O.CAN.KLSX.FF.W.0045.000000T0000Z-200730T1745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Madison IL-St. Louis City MO-St. Charles MO-St. Louis MO-
1216 PM CDT Thu Jul 30 2020
...THE FLASH FLOOD WARNING FOR SOUTHWESTERN MADISON COUNTY IN
SOUTHWESTERN ILLINOIS...NORTHEASTERN ST. CHARLES AND ST. LOUIS
COUNTIES IN EAST CENTRAL MISSOURI AND ST. LOUIS CITY IS CANCELLED...
The heavy rain has ended. Flood waters have receded. Flooding is no
longer expected to pose a threat. Please continue to heed any
remaining road closures.
LAT...LON 3867 9019 3861 9018 3854 9025 3843 9031
3844 9034 3846 9034 3845 9041 3848 9042
3849 9040 3850 9041 3850 9061 3878 9075
3889 9074 3891 9065 3888 9061 3887 9056
3891 9050 3895 9048 3897 9041 3884 9010
$$
MaplesThe office that day
Everything else NWS St. Louis, MO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 30, 2:17 AM CDT | Areal Flood Advisory | LSX | Saint Charles, Saint Louis, City of Saint Louis | 6 hr |
| Jul 30, 8:04 AM CDT | Areal Flood Advisory | LSX | Macoupin, Montgomery | 6 hr |
Nearby
Flash Flood Warnings in Missouri, 2020Flash Flood Warnings in Illinois, 2020Every flash flood warning in 2020
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.