Alert archive / Missouri / Areal Flood Advisories in 2021

Areal Flood Advisory 21, NWS St. Louis, MO

June 30, 2021Adams County, Illinois; Lewis County, Marion County, Missouri

NWS St. Louis, MO issued this areal flood advisory at Jun 30, 2021, 4:03 PM CDT for Adams County, Illinois; Lewis County, Marion County, Missouri. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Jun 30, 2021, 4:03 PM CDT (21:03 UTC)
Expired
Jun 30, 2021, 7:07 PM CDT
In force
3 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon

Counties Adams County, IL, Lewis County, MO, Marion County, MO

The radar

The St Louis radar (KLSX), 151 km from the middle of the area, began a volume at 21:04 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

Davenport, (KDVN), launched 12:00Z, 9.1 hours before the alert went out and 216 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 12:00Z on 2021-06-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 377 joules per kilogram.LCLLFCEL10008507005003002001001 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, Davenport, at 12:00Z on 2021-06-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 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
377 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
738 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
40 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.3

Open this sounding in Storm Lab

The text

As transmitted.

558 
WGUS83 KLSX 302103
FLSLSX

Flood Advisory
National Weather Service St Louis MO
403 PM CDT Wed Jun 30 2021

ILC001-MOC111-127-010015-
/O.NEW.KLSX.FA.Y.0021.210630T2103Z-210701T0015Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Adams IL-Lewis MO-Marion MO-
403 PM CDT Wed Jun 30 2021

The National Weather Service in St Louis has issued a

* Urban and Small Stream Flood Advisory for...
  West Central Adams County in west central Illinois...
  Southeastern Lewis County in northeastern Missouri...
  Central Marion County in northeastern Missouri...

* Until 715 PM CDT.

* At 403 PM CDT, Doppler radar indicated heavy rain due to 
  thunderstorms. This will cause urban and small stream flooding. 
  Between 1 and 2 inches of rain have fallen.

* Some locations that will experience flooding include...
  Quincy, Palmyra, Warren, Maywood, Philadelphia and Taylor.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 3997 9162 3998 9130 3984 9143 3970 9160
      3970 9179 3987 9179

$$

MRB
2 follow-up statements
354 
WGUS83 KLSX 302245
FLSLSX

Flood Advisory
National Weather Service St Louis MO
545 PM CDT Wed Jun 30 2021

ILC001-MOC111-127-010015-
/O.CON.KLSX.FA.Y.0021.000000T0000Z-210701T0015Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Adams IL-Lewis MO-Marion MO-
545 PM CDT Wed Jun 30 2021

...THE URBAN AND SMALL STREAM FLOOD ADVISORY REMAINS IN EFFECT UNTIL 
715 PM CDT THIS EVENING FOR WEST CENTRAL ADAMS COUNTY IN WEST 
CENTRAL ILLINOIS AND SOUTHEASTERN LEWIS AND CENTRAL MARION COUNTIES 
IN NORTHEASTERN MISSOURI...

At 545 PM CDT, Doppler radar indicated heavy rain due to 
thunderstorms. This will cause urban and small stream flooding. 
Between 1 and 2 inches of rain have fallen.

Some locations that will experience flooding include...
  Quincy, Palmyra, Warren, Maywood, Philadelphia and Taylor.

Additional rainfall amounts of 1 to 2 inches are expected over the 
area. This additional rain will result in minor flooding.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 3997 9162 3998 9130 3984 9143 3970 9160
      3970 9179 3987 9179

$$

MRB
336 
WGUS83 KLSX 010007
FLSLSX

Flood Advisory
National Weather Service St Louis MO
707 PM CDT Wed Jun 30 2021

ILC001-MOC111-127-010017-
/O.CAN.KLSX.FA.Y.0021.000000T0000Z-210701T0015Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Adams IL-Lewis MO-Marion MO-
707 PM CDT Wed Jun 30 2021

...THE URBAN AND SMALL STREAM FLOOD ADVISORY IS CANCELLED FOR WEST 
CENTRAL ADAMS COUNTY IN WEST CENTRAL ILLINOIS AND SOUTHEASTERN LEWIS 
AND CENTRAL MARION COUNTIES IN NORTHEASTERN MISSOURI...

The heavy rain has ended. Urban and small stream flooding is no 
longer expected to pose a threat. Please continue to heed remaining 
road closures.

LAT...LON 3997 9162 3998 9130 3984 9143 3970 9160
      3970 9179 3987 9179

$$

MRB

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 30, 4:34 PM CDTAreal Flood AdvisoryLSXAdams46 min
Jun 30, 5:20 PM CDTFlash Flood WarningLSXAdams2 hr
Jun 29, 8:41 PM CDTRiver Flood WarningLSXLewis30 hr
Jun 30, 3:30 AM CDTFlash Flood WatchLSXAudrain, Boone, Callaway, Cole, Crawford, Franklin and 8 more33 hr
Jun 30, 5:15 AM CDTAreal Flood AdvisoryLSXBoone, Moniteau3 hr
Jun 30, 5:44 AM CDTRiver Flood WarningLSXLincoln49 hr
Jun 30, 5:59 AM CDTAreal Flood AdvisoryLSXBoone, Callaway3 hr
Jun 30, 7:01 AM CDTAreal Flood AdvisoryLSXMontgomery3 hr
Jun 30, 7:49 AM CDTAreal Flood AdvisoryLSXLincoln, Montgomery, Warren3 hr
Jun 30, 6:00 PM CDTRiver Flood WarningLSXMarion22 hr
Jun 30, 6:00 PM CDTRiver Flood WarningLSXMarion19 hr

Nearby

Areal Flood Advisories in Missouri, 2021Areal Flood Advisories in Illinois, 2021Every 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.