Alert archive / Missouri / Flash Flood Watches in 2021
Flash Flood Watch 1, NWS St. Louis, MO
NWS St. Louis, MO issued this flash flood watch at Mar 17, 2021, 2:49 AM CDT for 7 counties in Missouri; Randolph County, Washington County, Illinois. It took effect at Mar 17, 2021, 10:00 AM CDT. It was in force for 15 hr.
The area
The counties it named.
The facts
- Issued
- Mar 17, 2021, 2:49 AM CDT (07:49 UTC)
- In effect from
- Mar 17, 2021, 10:00 AM CDT
- Expired
- Mar 18, 2021, 1:17 AM CDT
- In force
- 15 hr
- Issued by
- NWS St. Louis, MO
- Flood severity
- None
Counties Randolph County, IL, Washington County, IL, Crawford County, MO, Iron County, MO, Madison County, MO, Reynolds County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Washington County, MO
The radar
The St Louis radar (KLSX), 100 km from the middle of the area, began a volume at 07:49 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.
The nearest sounding before it
Lincoln, IL (KILX), launched 00:00Z, 7.8 hours before the alert went out and 305 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 602 m above ground
- 0-6 km bulk shear
- 55 kt
- 0-1 km storm-relative helicity
- 118 m²/s²
- 0-3 km storm-relative helicity
- 183 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
378 WGUS63 KLSX 170749 FFALSX URGENT - IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service St Louis MO 249 AM CDT Wed Mar 17 2021 ILZ074-079-MOZ072>075-084-085-099-171600- /O.NEW.KLSX.FF.A.0001.210317T1500Z-210318T1200Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Washington IL-Randolph IL-Crawford MO-Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-Madison MO-Reynolds MO- Including the cities of Farmington, Chester, and Sparta 249 AM CDT Wed Mar 17 2021 ...FLASH FLOOD WATCH IN EFFECT FROM 10 AM CDT THIS MORNING THROUGH THURSDAY MORNING... The National Weather Service in St Louis has issued a * Flash Flood Watch for Portions of Illinois, including the following areas, Randolph IL and Washington IL. Portions of Missouri, including the following areas, Crawford MO, Iron MO, Madison MO, Reynolds MO, Saint Francois MO, Sainte Genevieve MO and Washington MO. * From 10 AM CDT this morning through Thursday morning. * Numerous thunderstorms will move through the area between late Wednesday morning and Wednesday evening, producing heavy rain. Localized flash flooding will be possible, particularly in areas that see multiple rounds of thunderstorms. * Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Low-water crossings may be flooded. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ BRC
2 follow-up statements
422 WGUS63 KLSX 171946 FFALSX Flood Watch National Weather Service St Louis MO 246 PM CDT Wed Mar 17 2021 ILZ074-079-MOZ072>075-084-085-099-181100- /O.CON.KLSX.FF.A.0001.000000T0000Z-210318T1200Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Washington IL-Randolph IL-Crawford MO-Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-Madison MO-Reynolds MO- Including the cities of Farmington, Chester, and Sparta 246 PM CDT Wed Mar 17 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THURSDAY MORNING... The Flash Flood Watch continues for * Portions of Illinois, including the following areas, Randolph IL and Washington IL. Portions of Missouri, including the following areas, Crawford MO, Iron MO, Madison MO, Reynolds MO, Saint Francois MO, Sainte Genevieve MO and Washington MO. * Through Thursday morning. * An additional round of thunderstorms is expected this evening. Localized flash flooding will be possible. * Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Low-water crossings may be flooded. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ Gosselin
792 WGUS63 KLSX 180617 FFALSX Flood Watch National Weather Service St Louis MO 117 AM CDT Thu Mar 18 2021 ILZ074-079-MOZ072>075-084-085-099-180730- /O.CAN.KLSX.FF.A.0001.000000T0000Z-210318T1200Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Washington IL-Randolph IL-Crawford MO-Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-Madison MO-Reynolds MO- Including the cities of Farmington, Chester, and Sparta 117 AM CDT Thu Mar 18 2021 ...FLASH FLOOD WATCH IS CANCELLED... The Flash Flood Watch for Portions of Illinois, including the following areas, Randolph IL and Washington IL. Portions of Missouri, including the following areas, Crawford MO, Iron MO, Madison MO, Reynolds MO, Saint Francois MO, Sainte Genevieve MO and Washington MO. has been cancelled. The Flash Flood Watch is cancelled. The threat of flash flooding has diminished across the watch area with decreasing potential for heavy rainfall. $$ Pfahler
The office that day
Everything else NWS St. Louis, MO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 17, 7:52 AM CDT | Severe Thunderstorm Warning | LSX | Boone, Moniteau | 38 min |
| Mar 17, 9:39 AM CDT | Areal Flood Advisory | LSX | Audrain, Boone | 3 hr |
| Mar 17, 11:14 AM CDT | River Flood Warning | LSX | Gasconade, Montgomery | 4 days |
| Mar 17, 11:14 AM CDT | River Flood Warning | LSX | Callaway, Osage | 21 days |
| Mar 17, 11:14 AM CDT | River Flood Warning | LSX | Franklin, Warren | 21 days |
| Mar 17, 11:14 AM CDT | River Flood Warning | LSX | Saint Charles, Saint Louis | 4 days |
| Mar 17, 11:14 AM CDT | River Flood Warning | LSX | Boone, Callaway, Cole, Moniteau | 71 hr |
| Mar 17, 11:35 AM CDT | River Flood Warning | LSX | Boone | 10 hr |
| Mar 17, 12:05 PM CDT | River Flood Warning | LSX | Marion | 69 hr |
| Mar 17, 12:05 PM CDT | River Flood Warning | LSX | Marion | 42 hr |
| Mar 17, 12:05 PM CDT | River Flood Warning | LSX | Monroe | 3 days |
| Mar 17, 12:05 PM CDT | River Flood Warning | LSX | Lewis | 42 hr |
| Mar 17, 12:05 PM CDT | River Flood Warning | LSX | Lewis | 38 hr |
Nearby
Flash Flood Watches in Missouri, 2021Flash Flood Watches in Illinois, 2021Every flash 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.