Alert archive / Iowa / Special Weather Statements in 2021

Special Weather Statement, NWS Quad Cities, IA

August 25, 2021Jefferson County, Iowa

NWS Quad Cities, IA issued this special weather statement at Aug 25, 2021, 3:53 AM CDT for Jefferson County, Iowa. It was in force for 37 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Aug 25, 2021, 3:53 AM CDT (08:53 UTC)
Expired: Aug 25, 2021, 4:30 AM CDT
In force: 37 min
Issued by: NWS Quad Cities, IA
Hail: 0.00 in
Wind: 30

County Jefferson County, IA

The radar

The Quad Cities radar (KDVN), 121 km from the middle of the area, began a volume at 08:54 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, 8.9 hours before the alert went out and 294 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: 2737 J/kg
Mixed-layer CIN: -9 J/kg
Mixed-layer LCL: 1274 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 43 m²/s²
0-3 km storm-relative helicity: 120 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 4.3

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement 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 special weather statement went out at Aug 25, 3:18 AM CDT, 35 minutes earlier.

Area forecast discussion, Aug 25, 3:18 AM CDT, 35 minutes before

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Hazardous weather outlook, Aug 25, 3:48 AM CDT, 5 minutes before

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In the hours before

Special weather statement, Aug 25, 3:53 AM CDT, 0 minutes before

Special Weather Statement
National Weather Service Quad Cities IA/IL
353 AM CDT Wed Aug 25 2021

IAZ087-250930-
Jefferson IA-
353 AM CDT Wed Aug 25 2021

...Strong thunderstorms will impact portions of northern Jefferson
County through 430 AM CDT...

At 352 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Pleasant Plain to near Libertyville.
Movement was east at 25 mph.

HAZARD...Winds in excess of 30 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Fairfield, Maharishi Vedic City, Pleasant Plain, Brookville,
Fairfield Municipal Airport, Mac Coon Access, Salina, Perlee, East
Pleasant Plain, Germanville, Beckwith and Jefferson County
Fairgrounds.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with these storms and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 4116 9172 4100 9172 4101 9215 4116 9197
TIME...MOT...LOC 0852Z 267DEG 22KT 4115 9191 4100 9205

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...30 MPH

McClure

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 25, 7:15 AM CDT	Flash Flood Warning	DVN	Iowa, Keokuk, Washington	4 hr
Aug 24, 7:22 PM CDT	Special Weather Statement	DVN	Henry	53 min
Aug 25, 3:37 PM CDT	Special Weather Statement	DVN	Henry	53 min
Aug 25, 3:39 PM CDT	Severe Thunderstorm Warning	DVN	Henry	36 min
Aug 25, 3:43 PM CDT	Tornado Warning Tornado observed	DVN	Henry	17 min
Aug 25, 4:11 PM CDT	Severe Thunderstorm Warning Considerable damage threat	DVN	Henry	49 min
Aug 25, 4:46 PM CDT	Severe Thunderstorm Warning	DVN	Bureau	29 min
Aug 25, 4:59 PM CDT	Severe Thunderstorm Warning	DVN	Bureau, Putnam	46 min
Aug 25, 6:12 PM CDT	Special Weather Statement	DVN	McDonough	33 min

Nearby

Special Weather Statements in Iowa, 2021 Every special weather statement 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.