Alert archive / Missouri / Areal Flood Advisories in 2021

Areal Flood Advisory 37, NWS St. Louis, MO

July 10, 2021Saint Louis County, City of Saint Louis, Missouri

NWS St. Louis, MO issued this areal flood advisory at Jul 10, 2021, 12:41 AM CDT for Saint Louis County, City of Saint Louis, Missouri. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: Jul 10, 2021, 12:41 AM CDT (05:41 UTC)
Expired: Jul 10, 2021, 3:45 AM CDT
In force: 3 hr
Issued by: NWS St. Louis, MO
Area: Storm-based polygon

Counties City of Saint Louis, MO, Saint Louis County, MO

The radar

The St Louis radar (KLSX), 32 km from the middle of the area, began a volume at 05:45 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, 5.7 hours before the alert went out and 224 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1282 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 57 m²/s²
0-3 km storm-relative helicity: 177 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal flood advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS St. Louis, MO wrote its last area forecast discussion before this areal flood advisory went out at Jul 9, 10:57 PM CDT, 1 hour 44 minutes earlier.

Area forecast discussion, Jul 9, 10:57 PM CDT, 1 hour 44 minutes before

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Hazardous weather outlook, Jul 9, 2:55 PM CDT, 9 hours 46 minutes before

Hazardous Weather Outlook
National Weather Service Saint Louis MO
255 PM CDT Fri Jul 9 2021

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-102000-
Adams IL-Audrain MO-Bond IL-Boone MO-Brown IL-Calhoun IL-Callaway MO-
Clinton IL-Cole MO-Crawford MO-Fayette IL-Franklin MO-Gasconade MO-
Greene IL-Iron MO-Jefferson MO-Jersey IL-Knox MO-Lewis MO-Lincoln MO-
Macoupin IL-Madison IL-Madison MO-Marion IL-Marion MO-Moniteau MO-
Monroe IL-Monroe MO-Montgomery IL-Montgomery MO-Osage MO-Pike IL-
Pike MO-Ralls MO-Randolph IL-Reynolds MO-Saint Charles MO-
Saint Clair-Saint Francois MO-Saint Louis City MO-Saint Louis MO-
Sainte Genevieve MO-Shelby MO-Warren MO-Washington IL-Washington MO-
255 PM CDT Fri Jul 9 2021

This Hazardous Weather Outlook is for portions of eastern and
central Missouri as well as west central and southwest Illinois.

.DAY ONE...Tonight.

Severe thunderstorms are possible across portions of eastern
Missouri and western Illinois tonight. Damaging winds and isolated
tornadoes are the main threats.

Heavy rainfall is also possible tonight, mainly for portions of
northeast Missouri and west-central Illinois. Please see the flash
flood watch product for more details.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

The threat for heavy rainfall continues into Saturday morning.
Please see the flash flood watch product for more details.

Thunderstorms are likely on Saturday across the area. Some of these
storms may be strong to severe in southeast Missouri and southwest
Illinois.

Additional thunderstorms are possible across portions of the area
Sunday through Thursday.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures.

BSH

In the hours before

Local storm report, Jul 10, 12:06 AM CDT, 35 minutes before

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Local storm report, Jul 10, 12:17 AM CDT, 24 minutes before

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Local storm report, Jul 10, 12:26 AM CDT, 15 minutes before

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Local storm report, Jul 10, 12:30 AM CDT, 11 minutes before

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Local storm report, Jul 10, 12:33 AM CDT, 8 minutes before

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Local storm report, Jul 10, 12:39 AM CDT, 2 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 9, 8:21 PM CDT	Severe Thunderstorm Warning	LSX	Lewis, Marion	39 min
Jul 9, 8:55 PM CDT	Severe Thunderstorm Warning	LSX	Marion, Ralls	50 min
Jul 9, 8:58 PM CDT	Severe Thunderstorm Warning	LSX	Saint Charles, Saint Louis	62 min
Jul 9, 9:00 PM CDT	Severe Thunderstorm Warning	LSX	Knox	45 min
Jul 9, 9:08 PM CDT	Areal Flood Advisory	LSX	Lewis, Marion	32 min
Jul 9, 9:10 PM CDT	Severe Thunderstorm Warning	LSX	Knox, Lewis, Marion, Shelby	65 min
Jul 9, 9:14 PM CDT	Severe Thunderstorm Warning	LSX	Saint Louis, City of Saint Louis	48 min
Jul 9, 9:36 PM CDT	Severe Thunderstorm Warning	LSX	Marion, Monroe, Pike, Ralls, Shelby	54 min
Jul 9, 9:40 PM CDT	Flash Flood Warning	LSX	Lewis, Marion	3 hr
Jul 9, 10:10 PM CDT	Severe Thunderstorm Warning	LSX	Audrain, Lincoln, Monroe, Pike, Ralls	50 min
Jul 9, 10:32 PM CDT	Severe Thunderstorm Warning	LSX	Monroe, Shelby	23 min
Jul 9, 10:45 PM CDT	Severe Thunderstorm Warning	LSX	Audrain, Callaway, Lincoln, Montgomery, Pike, Warren	45 min
Jul 9, 11:08 PM CDT	Severe Thunderstorm Warning	LSX	Callaway, Franklin, Gasconade, Montgomery, Osage, Warren	67 min
Jul 9, 11:10 PM CDT	River Flood Warning	LSX	Lewis	5 days
Jul 9, 11:10 PM CDT	River Flood Warning	LSX	Lewis	32 hr
Jul 9, 11:10 PM CDT	River Flood Warning	LSX	Marion	4 days
Jul 9, 11:24 PM CDT	Areal Flood Advisory	LSX	Audrain, Marion, Monroe, Pike, Ralls, Shelby	3 hr
Jul 9, 11:28 PM CDT	Severe Thunderstorm Warning	LSX	Lincoln, Montgomery, Saint Charles, Warren	47 min
Jul 9, 11:57 PM CDT	Areal Flood Advisory	LSX	Lincoln, Pike	3 hr
Jul 9, 11:59 PM CDT	Severe Thunderstorm Warning	LSX	Franklin, Jefferson, Lincoln, Saint Charles, Saint Louis, Warren and 1 more	61 min
Jul 10, 12:26 AM CDT	Areal Flood Advisory	LSX	Lincoln, Saint Charles	3 hr
Jul 10, 12:42 AM CDT	Severe Thunderstorm Warning	LSX	Jefferson, Saint Louis, City of Saint Louis	63 min
Jul 10, 1:08 AM CDT	Severe Thunderstorm Warning	LSX	Jefferson, Sainte Genevieve, Saint Francois, Washington	52 min
Jul 10, 1:49 AM CDT	River Flood Warning	LSX	Marion	18 hr
Jul 10, 1:50 AM CDT	Severe Thunderstorm Warning	LSX	Iron, Madison, Sainte Genevieve, Saint Francois, Washington	40 min
Jul 10, 2:29 AM CDT	Severe Thunderstorm Warning	LSX	Iron, Madison	21 min
Jul 10, 6:14 AM CDT	River Flood Warning	LSX	Monroe	4 days
Jul 10, 8:30 AM CDT	River Flood Warning	LSX	Lincoln	3 days
Jul 10, 2:15 PM CDT	Areal Flood Advisory	LSX	Saint Charles, Saint Louis	3 hr
Jul 9, 8:07 PM CDT	Severe Thunderstorm Warning	LSX	Adams, Brown	38 min
Jul 9, 8:43 PM CDT	Severe Thunderstorm Warning	LSX	Brown	47 min
Jul 9, 9:17 PM CDT	Severe Thunderstorm Warning	LSX	Brown, Pike	43 min
Jul 9, 10:03 PM CDT	Areal Flood Advisory	LSX	Adams, Brown, Pike	3 hr
Jul 10, 1:36 AM CDT	Severe Thunderstorm Warning	LSX	Bond, Clinton, Marion, Saint Clair, Washington	54 min
Jul 10, 2:49 AM CDT	River Flood Warning	LSX	Calhoun, Greene, Jersey	10 days
Jul 10, 3:05 PM CDT	Severe Thunderstorm Warning	LSX	Bond, Clinton, Madison, Saint Clair	21 min
Jul 10, 3:11 PM CDT	Areal Flood Advisory	LSX	Macoupin, Madison	3 hr
Jul 10, 4:31 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Marion, Randolph, Washington	59 min

Nearby

Areal Flood Advisories in Missouri, 2021 Every areal flood advisory 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.