Alert archive / Missouri / Flood Watches in 2021

Flood Watch 2, NWS St. Louis, MO

March 11, 202120 counties in Missouri; 7 counties in Illinois

NWS St. Louis, MO issued this flood watch at Mar 11, 2021, 3:27 AM CST for 20 counties in Missouri; 7 counties in Illinois. It took effect at Mar 11, 2021, 6:00 PM CST. It was in force for 41 hr.

The area

The counties it named.

The facts

Issued
Mar 11, 2021, 3:27 AM CST (09:27 UTC)
In effect from
Mar 11, 2021, 6:00 PM CST
Expired
Mar 13, 2021, 10:36 AM CST
In force
41 hr
Issued by
NWS St. Louis, MO
Flood severity
None
All 27 counties

Clinton County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Randolph County, IL, Saint Clair County, IL, Washington County, IL, Boone County, MO, Callaway County, MO, City of Saint Louis, MO, Cole County, MO, Crawford County, MO, Franklin County, MO, Gasconade County, MO, Iron County, MO, Jefferson County, MO, Madison County, MO, Moniteau County, MO, Montgomery County, MO, Osage County, MO, Reynolds County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Warren County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 39 km from the middle of the area, began a volume at 09:30 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 00:00Z, 9.5 hours before the alert went out and 273 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 00:00Z on 2021-03-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 00:00Z on 2021-03-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 236 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
906 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
236 m²/s²
0-3 km storm-relative helicity
244 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

837 
WGUS63 KLSX 110927
FFALSX

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service St Louis MO
327 AM CST Thu Mar 11 2021

ILZ069-070-074-079-100>102-MOZ041-047>051-059>065-072>075-084-085-
099-111730-
/O.NEW.KLSX.FA.A.0002.210312T0000Z-210314T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clinton IL-Marion IL-Washington IL-Randolph IL-Madison IL-Saint
Clair-Monroe IL-Boone MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-
Montgomery MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
Including the cities of Cahokia, Saint Charles, Alton, Centralia,
Farmington, Sparta, Washington, Saint Louis, Jefferson City,
Belleville, Salem, Edwardsville, Chester, Union, Columbia,
Sullivan, and Fulton
327 AM CST Thu Mar 11 2021

...FLOOD WATCH IN EFFECT FROM THIS EVENING THROUGH SATURDAY 
AFTERNOON...

The National Weather Service in St Louis has issued a

* Flood Watch for Portions of Illinois, including the following 
  areas, Clinton IL, Madison IL, Marion IL, Monroe IL, Randolph IL, 
  Saint Clair and Washington IL. Portions of Missouri, including the 
  following areas, Boone MO, Callaway MO, Cole MO, Crawford MO, 
  Franklin MO, Gasconade MO, Iron MO, Jefferson MO, Madison MO, 
  Moniteau MO, Montgomery MO, Osage MO, Reynolds MO, Saint Charles 
  MO, Saint Francois MO, Saint Louis City MO, Saint Louis MO, Sainte 
  Genevieve MO, Warren MO and Washington MO.

* From this evening through Saturday afternoon.

* A prolonged period of rain through Saturday. Between 1 and 3 
  inches of rainfall with locally higher amounts possible.

* Excessive runoff may result in flooding of rivers, creeks, 
  streams, and other low-lying and flood-prone locations.
  Creeks and streams may rise out of their banks.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be alert for possible Flood 
Warnings. Those living in areas prone to flooding should be prepared 
to take action should flooding develop.

&&

$$

Byrd
5 follow-up statements
184 
WGUS63 KLSX 112054
FFALSX

Flood Watch
National Weather Service St Louis MO
254 PM CST Thu Mar 11 2021

ILZ069-070-074-079-100>102-MOZ041-047>051-059>065-072>075-084-085-
099-121000-
/O.CON.KLSX.FA.A.0002.210312T0000Z-210314T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clinton IL-Marion IL-Washington IL-Randolph IL-Madison IL-Saint
Clair-Monroe IL-Boone MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-
Montgomery MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
Including the cities of Cahokia, Saint Charles, Alton, Centralia,
Farmington, Sparta, Washington, Saint Louis, Jefferson City,
Belleville, Salem, Edwardsville, Chester, Union, Columbia,
Sullivan, and Fulton
254 PM CST Thu Mar 11 2021

...FLOOD WATCH REMAINS IN EFFECT FROM 6 PM CST THIS EVENING THROUGH 
SATURDAY AFTERNOON...

The Flood Watch continues for

* Portions of Illinois, including the following areas, Clinton IL, 
  Madison IL, Marion IL, Monroe IL, Randolph IL, Saint Clair and 
  Washington IL. Portions of Missouri, including the following 
  areas, Boone MO, Callaway MO, Cole MO, Crawford MO, Franklin MO, 
  Gasconade MO, Iron MO, Jefferson MO, Madison MO, Moniteau MO, 
  Montgomery MO, Osage MO, Reynolds MO, Saint Charles MO, Saint 
  Francois MO, Saint Louis City MO, Saint Louis MO, Sainte Genevieve 
  MO, Warren MO and Washington MO.

* From 6 PM CST this evening through Saturday afternoon.

* A prolonged period of rain through Saturday. Between 1 and 3 
  inches of rainfall with locally higher amounts possible.

* Excessive runoff may result in flooding of rivers, creeks, 
  streams, and other low-lying and flood-prone locations.
  Creeks and streams may rise out of their banks.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be alert for possible Flood 
Warnings. Those living in areas prone to flooding should be prepared 
to take action should flooding develop.

&&

$$

TES
365 
WGUS63 KLSX 120939
FFALSX

Flood Watch
National Weather Service St Louis MO
339 AM CST Fri Mar 12 2021

ILZ069-070-074-079-100>102-MOZ041-047>051-059>065-072>075-084-085-
099-140000-
/O.CON.KLSX.FA.A.0002.000000T0000Z-210314T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clinton IL-Marion IL-Washington IL-Randolph IL-Madison IL-Saint
Clair-Monroe IL-Boone MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-
Montgomery MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
Including the cities of Cahokia, Saint Charles, Alton, Centralia,
Farmington, Sparta, Washington, Saint Louis, Jefferson City,
Belleville, Salem, Edwardsville, Chester, Union, Columbia,
Sullivan, and Fulton
339 AM CST Fri Mar 12 2021

...FLOOD WATCH REMAINS IN EFFECT THROUGH SATURDAY AFTERNOON...

The Flood Watch continues for

* Portions of Illinois, including the following areas, Clinton IL, 
  Madison IL, Marion IL, Monroe IL, Randolph IL, Saint Clair and 
  Washington IL. Portions of Missouri, including the following 
  areas, Boone MO, Callaway MO, Cole MO, Crawford MO, Franklin MO, 
  Gasconade MO, Iron MO, Jefferson MO, Madison MO, Moniteau MO, 
  Montgomery MO, Osage MO, Reynolds MO, Saint Charles MO, Saint 
  Francois MO, Saint Louis City MO, Saint Louis MO, Sainte Genevieve 
  MO, Warren MO and Washington MO.

* Through Saturday afternoon.

* A prolonged period of rain will continue through Saturday. Between 
  one half and two inches of additional rainfall with locally higher 
  amounts possible.

* Excessive runoff may result in flooding of rivers, creeks, 
  streams, and other low-lying and flood-prone locations.
  Creeks and streams may rise out of their banks.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be alert for possible Flood 
Warnings. Those living in areas prone to flooding should be prepared 
to take action should flooding develop.

&&

$$

Pfahler
604 
WGUS63 KLSX 122028
FFALSX

Flood Watch
National Weather Service St Louis MO
228 PM CST Fri Mar 12 2021

ILZ069-070-074-079-100>102-MOZ051-060-061-063-064-122130-
/O.CAN.KLSX.FA.A.0002.000000T0000Z-210314T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clinton IL-Marion IL-Washington IL-Randolph IL-Madison IL-Saint
Clair-Monroe IL-Montgomery MO-Warren MO-Saint Charles MO-Saint
Louis MO-Saint Louis City MO-
Including the cities of Cahokia, Saint Charles, Alton, Centralia,
Sparta, Saint Louis, Belleville, Salem, Edwardsville, and Chester
228 PM CST Fri Mar 12 2021

...FLOOD WATCH IS CANCELLED...

The Flood Watch for Portions of Illinois, including the following 
areas, Clinton IL, Madison IL, Marion IL, Monroe IL, Randolph IL, 
Saint Clair and Washington IL. Portions of east central Missouri, 
including the following areas, Montgomery MO, Saint Charles MO, 
Saint Louis City MO, Saint Louis MO and Warren MO. has been 
cancelled.

The Flood Watch is cancelled. Rainfall amounts are forecasted to be 
much less than previously for tonight and Saturday. Additional 
rainfall is also forecast for Sunday and Monday.

$$

MOZ041-047>050-059-062-065-072>075-084-085-099-131100-
/O.CON.KLSX.FA.A.0002.000000T0000Z-210314T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Boone MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Gasconade MO-
Franklin MO-Jefferson MO-Crawford MO-Washington MO-Saint Francois
MO-Sainte Genevieve MO-Iron MO-Madison MO-Reynolds MO-
Including the cities of Columbia, Union, Farmington, Washington,
Jefferson City, Sullivan, and Fulton
228 PM CST Fri Mar 12 2021

...FLOOD WATCH REMAINS IN EFFECT THROUGH SATURDAY AFTERNOON...

The Flood Watch continues for

* Portions of central, east central, and southeast Missouri, 
  including the following areas, in central Missouri, Boone MO, 
  Callaway MO, Cole MO, Moniteau MO and Osage MO. In east central 
  Missouri, Crawford MO, Franklin MO, Gasconade MO, Jefferson MO and 
  Washington MO. In southeast Missouri, Iron MO, Madison MO, 
  Reynolds MO, Saint Francois MO and Sainte Genevieve MO.

* Through Saturday afternoon.

* Periods of rain, along with isolated thunderstorms, will continue 
  in this area through Saturday.  Additional rainfall amounts up to 
  2 inches with locally higher amounts will be possible.

* Excessive runoff may result in flooding of rivers, creeks, 
  streams, and other low-lying and flood-prone locations.
  Creeks and streams may rise out of their banks.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be alert for possible Flood 
Warnings. Those living in areas prone to flooding should be prepared 
to take action should flooding develop.

&&

$$

TES
792 
WGUS63 KLSX 130909
FFALSX

Flood Watch
National Weather Service St Louis MO
309 AM CST Sat Mar 13 2021

MOZ041-050-131015-
/O.CAN.KLSX.FA.A.0002.000000T0000Z-210314T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Boone MO-Callaway MO-
Including the cities of Columbia and Fulton
309 AM CST Sat Mar 13 2021

...FLOOD WATCH IS CANCELLED...

The Flood Watch for Boone MO and Callaway MO has been cancelled.

The Flood Watch is cancelled. The threat of flooding has shifted 
south of the area. Any additional rainfall through Saturday 
afternoon should be light.

$$

MOZ047>049-059-062-065-072>075-084-085-099-140000-
/O.CON.KLSX.FA.A.0002.000000T0000Z-210314T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Moniteau MO-Cole MO-Osage MO-Gasconade MO-Franklin MO-Jefferson
MO-Crawford MO-Washington MO-Saint Francois MO-Sainte Genevieve
MO-Iron MO-Madison MO-Reynolds MO-
Including the cities of Union, Jefferson City, Washington,
Sullivan, and Farmington
309 AM CST Sat Mar 13 2021

...FLOOD WATCH REMAINS IN EFFECT THROUGH THIS AFTERNOON...

The Flood Watch continues for

* Portions of central, east central, and southeast Missouri, 
  including the following areas, in central Missouri, Cole MO, 
  Moniteau MO and Osage MO. In east central Missouri, Crawford MO, 
  Franklin MO, Gasconade MO, Jefferson MO and Washington MO. In 
  southeast Missouri, Iron MO, Madison MO, Reynolds MO, Saint 
  Francois MO and Sainte Genevieve MO.

* Through this afternoon.

* Periods of rain will continue in this area into Saturday.  
  Additional rainfall amounts up to three quarters of an inch will 
  be possible on locations that have already experienced heavy 
  rainfall and flooding.

* Excessive runoff may result in flooding of rivers, creeks, 
  streams, and other low-lying and flood-prone locations.
  Creeks and streams may rise out of their banks.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be alert for possible Flood 
Warnings. Those living in areas prone to flooding should be prepared 
to take action should flooding develop.

&&

$$

Pfahler
728 
WGUS63 KLSX 131636
FFALSX

Flood Watch
National Weather Service St Louis MO
1036 AM CST Sat Mar 13 2021

MOZ047>049-059-062-065-072>075-084-085-099-131745-
/O.CAN.KLSX.FA.A.0002.000000T0000Z-210314T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Moniteau MO-Cole MO-Osage MO-Gasconade MO-Franklin MO-Jefferson
MO-Crawford MO-Washington MO-Saint Francois MO-Sainte Genevieve
MO-Iron MO-Madison MO-Reynolds MO-
Including the cities of Union, Jefferson City, Washington,
Sullivan, and Farmington
1036 AM CST Sat Mar 13 2021

...FLOOD WATCH IS CANCELLED...

The Flood Watch for Portions of central, east central, and southeast 
Missouri, including the following areas, in central Missouri, Cole 
MO, Moniteau MO and Osage MO. In east central Missouri, Crawford MO, 
Franklin MO, Gasconade MO, Jefferson MO and Washington MO. In 
southeast Missouri, Iron MO, Madison MO, Reynolds MO, Saint Francois 
MO and Sainte Genevieve MO. has been cancelled.

The Flood Watch is cancelled. The potential for new flooding is very 
low through the rest of today. Please continue to heed remaining 
road closures.

$$

TES

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 11, 12:43 PM CSTSevere Thunderstorm WarningLSXIron, Madison, Sainte Genevieve, Saint Francois22 min
Mar 11, 1:58 PM CSTSevere Thunderstorm WarningLSXIron, Madison, Sainte Genevieve, Saint Francois47 min
Mar 11, 3:38 PM CSTAreal Flood AdvisoryLSXCrawford, Iron, Sainte Genevieve, Saint Francois, Washington3 hr

Nearby

Flood Watches in Missouri, 2021Flood Watches in Illinois, 2021Every flood watch in 2021

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.