Alert archive / Illinois / Special Weather Statements in 2021

Special Weather Statement, NWS Quad Cities, IA

September 7, 2021Putnam County, Illinois

NWS Quad Cities, IA issued this special weather statement at Sep 7, 2021, 2:47 PM CDT for Putnam County, Illinois. It was in force for 28 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: Sep 7, 2021, 2:47 PM CDT (19:47 UTC)
Expired: Sep 7, 2021, 3:15 PM CDT
In force: 28 min
Issued by: NWS Quad Cities, IA
Hail: 0.50 in
Wind: 40

County Putnam County, IL

The radar

The Quad Cities radar (KDVN), 98 km from the middle of the area, began a volume at 19:49 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

Davenport, (KDVN), launched 12:00Z, 7.8 hours before the alert went out and 93 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: 827 J/kg
Mixed-layer CIN: -263 J/kg
Mixed-layer LCL: 1475 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 185 m²/s²
0-3 km storm-relative helicity: 167 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

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 Sep 7, 2:37 PM CDT, 10 minutes earlier.

Area forecast discussion, Sep 7, 2:37 PM CDT, 10 minutes before

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Hazardous weather outlook, Sep 7, 1:20 PM CDT, 1 hour 27 minutes before

Hazardous Weather Outlook
National Weather Service Quad Cities IA IL
120 PM CDT Tue Sep 7 2021

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-081830-
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-
120 PM CDT Tue Sep 7 2021

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

Isolated severe thunderstorms are possible this afternoon, mainly
southeast of a line from Morrison, Illinois to Burlington, Iowa.
The primary threats are damaging winds and large hail.

The Wapsipinicon River is experiencing flooding. Please see the
latest Flood Statements and Flood Warnings for details.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is likely this afternoon, mainly for portions
of northwest and west central Illinois.

In the hours before

Special weather statement, Sep 7, 12:37 PM CDT, 2 hours 10 minutes before

Special Weather Statement
National Weather Service Quad Cities IA/IL
1237 PM CDT Tue Sep 7 2021

ILZ007-009-071815-
Whiteside IL-Carroll IL-
1237 PM CDT Tue Sep 7 2021

...A strong thunderstorm will impact portions of northeastern
Whiteside and southeastern Carroll Counties through 115 PM CDT...

At 1236 PM CDT, Doppler radar was tracking a strong thunderstorm over
Argo Fay, or 7 miles south of Mount Carroll, moving east at 45 mph.

HAZARD...Winds up to 40 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

This strong thunderstorm will be near...
  Fairhaven around 1240 PM CDT.
  Chadwick around 1245 PM CDT.
  Milledgeville around 1250 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4196 9007 4202 9005 4200 8969 4193 8969
      4193 8963 4188 8963
TIME...MOT...LOC 1736Z 278DEG 40KT 4198 9000

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

08

Local storm report, Sep 7, 12:56 PM CDT, 1 hour 51 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1256 PM CDT TUE SEP 7 2021

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

1243 PM     HAIL             2 W USTICK              41.88N 90.04W
09/07/2021  E1.00 INCH       WHITESIDE          IL   TRAINED SPOTTER

&&

Special weather statement, Sep 7, 2:20 PM CDT, 27 minutes before

Special Weather Statement
National Weather Service Quad Cities IA/IL
220 PM CDT Tue Sep 7 2021

ILZ017-018-071945-
Bureau IL-Putnam IL-
220 PM CDT Tue Sep 7 2021

...Strong thunderstorms will impact portions of northeastern Putnam
and central Bureau Counties through 245 PM CDT...

At 219 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Mendota to 6 miles south of Walnut to near
Sheffield. Movement was east at 45 mph.

HAZARD...Winds up to 40 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
  Tiskilwa, La Moille, Hennepin, Spring Valley, DePue, Ladd, Dalzell
  and Bureau Junction.

This includes the following highways...
 Interstate 80 in Illinois between mile markers 44 and 72.
 Interstate 180 between mile markers 1 and 13.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 900 PM CDT for
north central Illinois.

&&

LAT...LON 4124 8929 4130 8984 4147 8960 4159 8917
      4158 8917 4124 8916
TIME...MOT...LOC 1919Z 275DEG 39KT 4158 8918 4147 8954 4131 8978

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

08

Special weather statement, Sep 7, 2:47 PM CDT, 0 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 7, 12:37 PM CDT	Special Weather Statement	DVN	Carroll	38 min
Sep 7, 12:47 PM CDT	Severe Thunderstorm Warning	DVN	Whiteside	29 min
Sep 7, 2:20 PM CDT	Special Weather Statement	DVN	Bureau	25 min

Nearby

Special Weather Statements in Illinois, 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.