Alert archive / Illinois / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 91, NWS Quad Cities, IA

April 20, 2023Bureau County, Henry County, Illinois

NWS Quad Cities, IA issued this severe thunderstorm warning at Apr 20, 2023, 4:05 PM CDT for Bureau County, Henry County, Illinois. It was in force for 40 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Apr 20, 2023, 4:05 PM CDT (21:05 UTC)
Expired: Apr 20, 2023, 4:45 PM CDT
In force: 40 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Tornado: Possible
Hail: 1.5 in
Wind: 60.0 mph

Counties Bureau County, IL, Henry County, IL

The radar

The Quad Cities radar (KDVN), 68 km from the middle of the area, began a volume at 21:09 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Apr 20, 2:06 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 9.1 hours before the alert went out and 62 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: 1350 m above ground
0-6 km bulk shear: 60 kt
0-1 km storm-relative helicity: 44 m²/s²
0-3 km storm-relative helicity: 166 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 severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Quad Cities, IA wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 20, 2:02 PM CDT, 2 hours 3 minutes earlier.

Area forecast discussion, Apr 20, 2:02 PM CDT, 2 hours 3 minutes before

Area Forecast Discussion
National Weather Service Quad Cities IA IL
202 PM CDT Thu Apr 20 2023

.SYNOPSIS...
Issued at 159 PM CDT Thu Apr 20 2023

Latest sfc analysis was indicating a low center currently acrs
northeast IA/far southeast MN, with trailing front down along and
west of the DVN CWA placing the local area in the warm sector.
Morning convective debris with passing MCV has dissipated, but pre
to post-frontal stratocu deck has filled in acrs much of the CWA
from the west. Some wake low wind phenomena going on acars eastern
IA behind the MCV decay with southwest gusts of 40-50 MPH. SBCAPEs
are growing acrs the southeastern third of the CWA with sfc DPTS
rising to near 60 along with some cloud break heating. Deep shear
profiles are ranging from 50 to 65+ KTs, thus the slight risk
along and east of the MS RVR looks warranted.

&&

.SHORT TERM...(This evening through Friday)
Issued at 159 PM CDT Thu Apr 20 2023

Afternoon and Tonight...Combo of 1000-1500 J/kg MUCAPEs and strong
storm bearing shear profiles support the severe risk along and east
of the MS RVR/west central into NW IL, with all modes of severe
possible including tornadoes with thermodynamic/kinematic profiles
supporting supercell structures. Most prime looking areas for this
activity appear to be along an east of a Kahoka MO, to Burlington IA
to Sterling IL line thru 6-7 PM before moving off to the east. After
storms clear off to the east, breezy post-frontal west winds of 15
to 30 mph for much of the evening, before decreasing after midnight
into early Friday morning. Cool air advection to usher in low temps
in the mid to upper 30s northwest, to the low to mid 40s in the
southeast.

Friday...Stacking cyclonic flow and very steep LLVL lapse rates up
to H85 or even H8 MB to drive breezy WSW sfc winds of 15 to 25 MPH
and gusts to 35 MPH. These parameters also to make the most of
cooling thermal profiles with some insolation to produce high temps
in the low 50s northwest, to the mid 60s southeast. Some sctrd wrap
around instability showers possible especially in the northwest in
the afternoon, and with classic looking inverted-V fcst soundings,
the showers may produce enhanced downward mixed wind gusts up to 50
MPH.  ..12..

.LONG TERM...(Friday night through Thursday)
Issued at 159 PM CDT Thu Apr 20 2023

Key Messages:

1. Temperatures Friday night through Monday morning near freezing
with frost and or freeze headlines possible across eastern Iowa,
northwest Illinois, and far northeast Missouri.

2. Below normal temperatures through the period with Saturday .

Discussion:

A closed 500 mb low will sit across the Upper Midwest through
Sunday. Spokes of vorticity rotating around the upper level low will
bring clouds to the area along with the potential for showers
especially Friday night into Saturday morning. Temperatures aloft
are cooling enough that any showers Friday night would be a mix of
rain and snow or rain, snow, and sleet. Little if any accumulation
is expected. This will also keep temperatures from bottoming out
Friday night although temperatures below freezing are possible
west of a line from Memphis Missouri to Dubuque Iowa.

Models show the 500 MB low slowly lifting northward through the day
on Saturday which will lift the clouds farther to the north.  this
may lead to continue showers during the day on Saturday. It will be
noticeably cooler with temperatures in the 40s. With clouds
clearing, temperatures will quickly fall off with the possibility of
widespread temperatures below freezing across the entire area. A
slight rebound in temperatures will occur on Sunday with high
temperatures in the upper 40s to lower 50s.

Monday through Wednesday some uncertainty in the forecast as a
shortwave trough passes to our south with some ridging building into
our area ahead of this shortwave. This will keep the precipitation
to our south through the period.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1240 PM CDT Thu Apr 20 2023

Gusty wake low winds up to 40 KTs from the southwest behind
decaying morning showers/storms through 2 pm, then decreasing some
to 20-30 KTs later this afternoon. Will have to watch for sctrd
thunderstorm development ahead of an incoming front this
afternoon, especially along and east of the MS RVR. Mainly VFR
clouds with a few bouts of MVFR CIGs/VSBYs possible with this
activity this afternoon, before improving later tonight. VFR late
night into Friday morning after post-frontal MVFR cloud deck
moves off to the east.

&&

.HYDROLOGY...
Issued at 159 PM CDT Thu Apr 20 2023

The 2023 Spring Snowmelt Flood will continue to work its way down
the main stem Mississippi River over the next couple of weeks.

All points on the Mississippi River continue to rise today. This
morning, we upgraded the flood warnings on the Mississippi River at
Fulton, Gladstone, and Burlington from Moderate to Major Flood. The
Major Flood is maintained at the other locations on the Mississippi
River over the next 7 days. Additional rises are expected beyond the
7-day forecast.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

SYNOPSIS...12
SHORT TERM...12
LONG TERM...Cousins
AVIATION...12
HYDROLOGY...Cousins

Hazardous weather outlook, Apr 20, 11:41 AM CDT, 4 hours 24 minutes before

Hazardous Weather Outlook
National Weather Service Quad Cities IA IL
1141 AM CDT Thu Apr 20 2023

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-211100-
Buchanan-Delaware-Dubuque-Benton-Linn-Jones-Jackson-Iowa-Johnson-
Cedar-Clinton-Muscatine-Scott-Keokuk-Washington-Louisa-Jefferson-
Henry IA-Des Moines-Van Buren-Lee-Jo Daviess-Stephenson-Carroll-
Whiteside-Rock Island-Henry IL-Bureau-Putnam-Mercer-Henderson-
Warren-Hancock-McDonough-Scotland-Clark-
1141 AM CDT Thu Apr 20 2023

This Hazardous Weather Outlook is for portions of north central
Illinois...northwest Illinois...west central Illinois...east
central Iowa...northeast Iowa...southeast Iowa and northeast
Missouri.

.DAY ONE...THIS AFTERNOON AND TONIGHT

There is a Slight Risk or level 2 out of 5, for severe storms this
afternoon generally along and east of the Mississippi River.
Large hail, isolated tornadoes and damaging wind will be the
primary risks in the slight risk area. The rest of the Outlook
Area is in a Marginal Risk or level 1 for severe weather. Large
hail and damaging winds will be the primary threats in the
marginal risk areas. Localized heavy rain will also be possible
across much of the Outlook Area.

Locations along the Mississippi River will begin to experience
flooding this week. Please see the latest Flood Statements and
Flood Warnings for details.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

Below freezing temperatures will be possible from Friday night,
Saturday night and Sunday night. This may impact sensitive
vegetation if not protected or covered.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed this afternoon.

12

In the hours before

Local storm report, Apr 20, 3:45 PM CDT, 20 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
345 PM CDT THU APR 20 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0341 PM     HAIL             MOUNT CARROLL           42.10N 89.98W
04/20/2023  M0.88 INCH       CARROLL            IL   PUBLIC

            REPORTED VIA SOCIAL MEDIA.

&&

JTS

Local storm report, Apr 20, 3:47 PM CDT, 18 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
347 PM CDT THU APR 20 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0320 PM     HAIL             ORION                   41.35N 90.37W
04/20/2023  E1.75 INCH       HENRY              IL   PUBLIC

            RELAYED BY BROADCAST MEDIA. VIEWER PHOTO.

&&

DC

Local storm report, Apr 20, 3:50 PM CDT, 15 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
350 PM CDT THU APR 20 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0337 PM     HAIL             GENESEO                 41.45N 90.15W
04/20/2023  E1.75 INCH       HENRY              IL   PUBLIC

            MEDIA RELAYED A VIEWER PHOTO OF GOLF BALL
            SIZE HAIL.

&&

DC

Local storm report, Apr 20, 3:52 PM CDT, 13 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
352 PM CDT THU APR 20 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0345 PM     HAIL             GENESEO                 41.45N 90.15W
04/20/2023  M1.00 INCH       HENRY              IL   BROADCAST MEDIA

&&

DC

Local storm report, Apr 20, 3:55 PM CDT, 10 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
355 PM CDT THU APR 20 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0320 PM     HAIL             ORION                   41.35N 90.37W
04/20/2023  E1.75 INCH       HENRY              IL   PUBLIC

            RELAYED VIA SOCIAL MEDIA.

&&

JTS

Local storm report, Apr 20, 4:05 PM CDT, 0 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
405 PM CDT THU APR 20 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0402 PM     HAIL             2 SW GALVA              41.15N 90.06W
04/20/2023  M0.88 INCH       HENRY              IL   EMERGENCY MNGR

            NICKEL HAIL 1.5 MILES SOUTHWEST OF GALVA.

&&

HAASE

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 20, 12:04 AM CDT	Special Weather Statement	DVN	Benton, Iowa	41 min
Apr 20, 12:45 AM CDT	Special Weather Statement	DVN	Benton, Buchanan, Iowa, Johnson, Linn	45 min
Apr 20, 1:12 AM CDT	Special Weather Statement	DVN	Johnson, Keokuk	48 min
Apr 20, 1:28 AM CDT	Special Weather Statement	DVN	Linn	47 min
Apr 20, 1:57 AM CDT	Special Weather Statement	DVN	Cedar, Johnson	48 min
Apr 20, 2:17 AM CDT	Special Weather Statement	DVN	Cedar, Jones	43 min
Apr 20, 2:32 AM CDT	Severe Thunderstorm Warning	DVN	Clinton, Scott	28 min
Apr 20, 8:24 AM CDT	Special Weather Statement	DVN	Des Moines, Henry, Louisa	36 min
Apr 20, 1:45 PM CDT	Special Weather Statement	DVN	Henry	30 min
Apr 20, 1:54 PM CDT	Special Weather Statement	DVN	Lee	51 min
Apr 20, 1:57 PM CDT	Severe Thunderstorm Warning	DVN	Des Moines, Henry, Lee	48 min
Apr 20, 2:17 PM CDT	Tornado Warning	DVN	Lee	43 min
Apr 20, 3:10 PM CDT	Severe Thunderstorm Warning	DVN	Clinton	35 min
Apr 20, 3:05 AM CDT	Special Weather Statement	DVN	Jo Daviess	25 min
Apr 20, 3:32 AM CDT	Special Weather Statement	DVN	Stephenson	28 min
Apr 20, 7:47 AM CDT	Special Weather Statement	DVN	Hancock	43 min
Apr 20, 8:46 AM CDT	Special Weather Statement	DVN	Hancock, Henderson	44 min
Apr 20, 9:05 AM CDT	Special Weather Statement	DVN	Henderson, Mercer, Rock Island, Warren	40 min
Apr 20, 9:09 AM CDT	Special Weather Statement	DVN	McDonough, Warren	36 min
Apr 20, 9:34 AM CDT	Special Weather Statement	DVN	Henry, Rock Island	41 min
Apr 20, 2:15 PM CDT	Severe Thunderstorm Warning	DVN	Hancock, McDonough	60 min
Apr 20, 2:51 PM CDT	Severe Thunderstorm Warning	DVN	Mercer	24 min
Apr 20, 3:05 PM CDT	Severe Thunderstorm Warning	DVN	Henry, Mercer, Rock Island	40 min
Apr 20, 3:05 PM CDT	Severe Thunderstorm Warning	DVN	Henderson, Warren	40 min
Apr 20, 3:10 PM CDT	Severe Thunderstorm Warning Considerable damage threat	DVN	McDonough	35 min
Apr 20, 3:14 PM CDT	Tornado Warning	DVN	McDonough	20 min
Apr 20, 3:21 PM CDT	Tornado Warning	DVN	Henry, Mercer	39 min
Apr 20, 3:25 PM CDT	Severe Thunderstorm Warning	DVN	Henry, Mercer, Warren	50 min
Apr 20, 3:33 PM CDT	Severe Thunderstorm Warning	DVN	Carroll, Stephenson, Whiteside	42 min
Apr 20, 3:46 PM CDT	Severe Thunderstorm Warning Considerable damage threat	DVN	Bureau, Henry, Whiteside	29 min
Apr 20, 3:53 PM CDT	Severe Thunderstorm Warning	DVN	Whiteside	34 min
Apr 20, 3:56 PM CDT	Tornado Warning	DVN	Carroll, Whiteside	22 min
Apr 20, 4:19 PM CDT	Tornado Warning	DVN	Bureau, Henry	26 min
Apr 20, 4:29 PM CDT	Tornado Warning Tornado observed	DVN	Bureau	15 min
Apr 20, 4:36 PM CDT	Severe Thunderstorm Warning Considerable damage threat	DVN	Bureau, Putnam	39 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2023 Every severe thunderstorm warning in 2023

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.