Alert archive / Illinois / Special Weather Statements in 2017

Special Weather Statement, NWS Quad Cities, IA

June 28, 2017Stephenson County, Illinois

NWS Quad Cities, IA issued this special weather statement at Jun 28, 2017, 9:55 PM CDT for Stephenson County, Illinois. It was in force for 35 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: Jun 28, 2017, 9:55 PM CDT (02:55 UTC)
Expired: Jun 28, 2017, 10:30 PM CDT
In force: 35 min
Issued by: NWS Quad Cities, IA

County Stephenson County, IL

The radar

The Milwaukee radar (KMKX), 110 km from the middle of the area, began a volume at 02:59 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 00:00Z, 2.9 hours before the alert went out and 110 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: 1521 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1099 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 259 m²/s²
0-3 km storm-relative helicity: 334 m²/s²
Significant tornado parameter: 2.7
Supercell composite: 15.1

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 Jun 28, 6:56 PM CDT, 2 hours 59 minutes earlier.

Area forecast discussion, Jun 28, 6:56 PM CDT, 2 hours 59 minutes before

Area Forecast Discussion
National Weather Service Quad Cities IA IL
656 PM CDT Wed Jun 28 2017

...AVIATION UPDATE...

.SYNOPSIS...
Issued at 323 PM CDT Wed Jun 28 2017

Thunderstorms have been festering over the forecast area through
much of the afternoon in the wake of the early morning heavy
rain producing storms. These storms have recently strengthened
some south of the Quad Cities. In the big picture, an upper level
shortwave was moving across northern IA and a 60 kt upper level
jet max is moving into western Iowa causing an uptick in storms
over northern and western IA and along the MO River in southwest
IA. Deep shear and increasing instability will favor severe storm
development and a tornado watch was just issued for most of IA and
northern MO.

&&

.SHORT TERM...(This Evening through Thursday)
ISSUED AT 323 PM CDT Wed Jun 28 2017

Severe weather and heavy rainfall will be the focus overnight
through at least Thursday night. Developing severe storms over
western and northern IA will likely evolve into a more linear
structure overnight and advance southeast over especially the
southern half of the local forecast area. Like last night, the
with abundant moisture, will continue a heavy rain threat. Deeper
wind shear, high CAPES and possibly boundary interactions will
lead to an enhanced severe risk with all modes including large
hail, damaging winds and tornadoes, especially late this afternoon
through evening. From late evening through overnight, the severe
threat will likely diminish, but will have to watch for any
possible back-building for a heavy rainfall threat, especially
over the forecast area south of I-80.

Forecast models largely continue the idea of the main boundary
stalling from west to east across southern IA or northern MO late
tonight and remaining there through Thursday. Additional mid level
shortwaves and high levels of moisture on a southwest low level
flow impinging on the boundary will continue the risk for heavy
rainfall and at least a slight risk for severe weather as
demonstrated by the SPC day 2 outlook with a slight risk over most
of the forecast area.

.LONG TERM...(Thursday Night through Wednesday)
ISSUED AT 323 PM CDT Wed Jun 28 2017

Another wave of showers and thunderstorms is possible for late
Friday into Saturday ahead of another shortwave traversing
through broad Upper Midwest/Great Lakes trough. However,
conditions will not be as conducive for heavy rainfall.

Semi-zonal to W/NW flow looks to keep things somewhat unsettled
late weekend through early next week with periodic shower
chances. Temperatures look to be near to slightly below normal
throughout the period.

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday Evening)
ISSUED AT 655 PM CDT Wed Jun 28 2017

Clusters of strong to severe storms with damaging wind, large hail
and very heavy rainfall will continue to move through eastern Iowa
early this evening. There will likely be a break in the storms
overnight, then additional storms Thursday morning in the
Burlington area, then possibly affecting all terminals Thursday
afternoon. Have kept conditions prevailing VFR, but there will be
a potential for MVFR low clouds and fog behind the rain, which is
not mentioned in the forecasts.

&&

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

SYNOPSIS...Sheets
SHORT TERM...Sheets
LONG TERM...Sheets
AVIATION...Sheets

Hazardous weather outlook, Jun 28, 12:11 PM CDT, 9 hours 44 minutes before

Hazardous Weather Outlook
National Weather Service Quad Cities Ia IL
1211 PM CDT Wed Jun 28 2017

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-291715-
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-
1211 PM CDT Wed Jun 28 2017

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

Severe thunderstorms are expected to develop this afternoon over
eastern Iowa and spread east to southeast across most of the
outlook area from late afternoon through evening. These storms
will likely develop west of highway 218 and north of Interstate 80
between 2 pm and 4 pm. Severe weather threats include damaging
wind, large hail, torrential rainfall and isolated tornadoes.

The Storm Prediction Center has placed most of eastern Iowa and
northwest Illinois in an enhanced risk for severe weather for this
afternoon and evening. All of west central Illinois and northeast
Missouri are in a slight risk for severe weather.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

Thunderstorms are again likely Thursday into Friday. There is a
risk of severe storms and very heavy rainfall, mainly south of
Highway 30 or roughly south of a line from Cedar Rapids Iowa to
Sterling Illinois.

Active weather will continue into next week with almost daily
chances for thunderstorms Saturday through Tuesday. At this time
it is too early to determine the threat for severe thunderstorms
beyond Friday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will be needed this afternoon and evening.

Sheets

In the hours before

Local storm report, Jun 28, 9:14 PM CDT, 41 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
914 PM CDT WED JUN 28 2017

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

0800 PM     TORNADO          OXFORD JUNCTION         41.98N 90.96W
06/28/2017                   JONES              IA   TRAINED SPOTTER

            APPROXIMATELY A HALF MILE SSW OF OXFORD
            JUNCTION.

&&

UTTECH

Special weather statement, Jun 28, 9:43 PM CDT, 12 minutes before

Special Weather Statement
National Weather Service Quad Cities IA
Issued by National Weather Service Des Moines IA
943 PM CDT WED JUN 28 2017

IAZ099-ILZ034-MOZ010-290345-
Hancock IL-Lee IA-Clark MO-
943 PM CDT WED JUN 28 2017

...Strong Thunderstorm to impact southern Clark and Hancock
counties...

At 942 PM CDT, Doppler radar was tracking a strong thunderstorm 8
miles southeast of Wyaconda, or 8 miles southwest of Kahoka, moving
east at 40 mph.

Half inch hail and wind gusts of 50 to 55 mph will be possible with
this storm.

Locations impacted include...
Keokuk, Carthage, Kahoka, Hamilton, Warsaw, Augusta, Wayland, Bowen,
Wyaconda, West Point, Alexandria, Luray, Winchester, Plymouth,
Denver, Elvaston, Basco, Bentley, Gregory Landing and Tioga.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Persons in campgrounds should consider seeking sturdy shelter until
this storm passes.

&&

A tornado watch remains in effect until midnight CDT for southeastern
Iowa...and northeastern Missouri.

LAT...LON 4020 9150 4025 9150 4025 9152 4026 9195
      4045 9194 4045 9091 4019 9091
TIME...MOT...LOC 0242Z 270DEG 33KT 4031 9180

RP Kinney

Local storm report, Jun 28, 9:49 PM CDT, 6 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
949 PM CDT WED JUN 28 2017

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

0716 PM     TSTM WND DMG     4 N MONTICELLO          42.30N 91.19W
06/28/2017                   DELAWARE           IA   EMERGENCY MNGR

            TWO DAMAGED HOUSES, POSSIBLE TORNADO.

&&

UTTECH

Local storm report, Jun 28, 9:53 PM CDT, 2 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
953 PM CDT WED JUN 28 2017

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

0717 PM     TSTM WND DMG     3 ESE HOPKINTON         42.33N 91.19W
06/28/2017                   DELAWARE           IA   EMERGENCY MNGR

            POWER LINES DOWN.

&&

UTTECH

Local storm report, Jun 28, 9:54 PM CDT, 1 minute before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
954 PM CDT WED JUN 28 2017

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

0715 PM     TSTM WND DMG     HOPKINTON               42.35N 91.25W
06/28/2017                   DELAWARE           IA   EMERGENCY MNGR

            LARGE BRANCHES DOWN.

&&

UTTECH

Special weather statement, Jun 28, 9:55 PM CDT, 0 minutes before

Special Weather Statement
National Weather Service Quad Cities IA
Issued by National Weather Service Des Moines IA
955 PM CDT WED JUN 28 2017

ILZ002-290330-
Stephenson IL-
955 PM CDT WED JUN 28 2017

...Strong Thunderstorm Impacting eastern Stephenson County...

At 955 PM CDT, Doppler radar was tracking a strong thunderstorm near
Pecatonica, or 11 miles east of Freeport, moving east at 65 mph.

Half inch hail and wind gusts of 50 to 55 mph will be possible with
this storm.

Locations impacted include...
Freeport, Cedarville, Dakota, German Valley, Ridott, Winneshiek,
Dakota Dornink Airport, Albertus Airport and Stephenson  County
Fairgrounds.

A tornado watch remains in effect until midnight CDT for northwestern
Illinois.

LAT...LON 4220 8946 4221 8962 4240 8965 4240 8940
      4220 8940
TIME...MOT...LOC 0255Z 256DEG 55KT 4229 8941

RP Kinney

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 28, 7:02 PM CDT	Severe Thunderstorm Warning	DVN	Benton, Buchanan, Linn	43 min
Jun 28, 7:24 PM CDT	Severe Thunderstorm Warning	DVN	Dubuque, Jackson	51 min
Jun 28, 7:24 PM CDT	Tornado Warning Tornado observedConsiderable damage threat	DVN	Dubuque, Jackson, Jones	51 min
Jun 28, 7:28 PM CDT	Severe Thunderstorm Warning	DVN	Cedar, Clinton, Jackson, Jones	38 min
Jun 28, 7:47 PM CDT	Tornado Warning	DVN	Clinton, Jackson, Jones	43 min
Jun 28, 8:01 PM CDT	Severe Thunderstorm Warning	DVN	Jones, Linn	23 min
Jun 28, 8:24 PM CDT	Tornado Warning Tornado observed	DVN	Jackson	51 min
Jun 28, 9:12 PM CDT	Severe Thunderstorm Warning	DVN	Benton, Linn	48 min
Jun 28, 9:18 PM CDT	River Flood Warning	DVN	Clinton, Scott	4 days
Jun 28, 10:03 PM CDT	Severe Thunderstorm Warning	DVN	Lee	42 min
Jun 29, 4:54 PM CDT	Special Weather Statement	DVN	Buchanan	36 min
Jun 28, 7:36 PM CDT	Severe Thunderstorm Warning	DVN	Jo Daviess, Stephenson	54 min
Jun 28, 8:27 PM CDT	Flash Flood Warning	DVN	Jo Daviess, Stephenson	6 hr
Jun 28, 9:43 PM CDT	Special Weather Statement	DVN	Hancock	62 min
Jun 29, 10:52 AM CDT	River Flood Warning	DVN	Stephenson	3 days
Jun 29, 10:52 AM CDT	River Flood Warning	DVN	Whiteside	7 days
Jun 29, 10:52 AM CDT	River Flood Warning	DVN	Henry, Rock Island, Whiteside	8 days
Jun 29, 10:52 AM CDT	River Flood Warning	DVN	Henry, Rock Island	7 days
Jun 28, 8:36 PM CDT	Special Weather Statement	DVN	Clark, Scotland	54 min
Jun 28, 8:58 PM CDT	Severe Thunderstorm Warning	DVN	Scotland	47 min

Nearby

Special Weather Statements in Illinois, 2017 Every special weather statement in 2017

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.