Alert archive / Iowa / Special Weather Statements in 2017

Special Weather Statement, NWS Quad Cities, IA

August 3, 2017Delaware County, Iowa

NWS Quad Cities, IA issued this special weather statement at Aug 3, 2017, 2:16 PM CDT for Delaware County, Iowa. It was in force for 59 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 3, 2017, 2:16 PM CDT (19:16 UTC)
Expired
Aug 3, 2017, 3:15 PM CDT
In force
59 min
Issued by
NWS Quad Cities, IA

County Delaware County, IA

The radar

The Quad Cities radar (KDVN), 128 km from the middle of the area, began a volume at 19:17 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, 7.3 hours before the alert went out and 131 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 2017-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1188 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 2017-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 44 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
1188 J/kg
Mixed-layer CIN
-41 J/kg
Mixed-layer LCL
1075 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
44 m²/s²
0-3 km storm-relative helicity
79 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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 3, 12:31 PM CDT, 1 hour 45 minutes earlier.

Area forecast discussion, Aug 3, 12:31 PM CDT, 1 hour 45 minutes before
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Hazardous weather outlook, Aug 3, 10:15 AM CDT, 4 hours 1 minute before
Hazardous Weather Outlook
National Weather Service Quad Cities IA IL
1015 AM CDT Thu Aug 3 2017

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-041515-
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-
1015 AM CDT Thu Aug 3 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...TODAY AND TONIGHT

A line of thunderstorms will move across eastern Iowa this
morning. These storms are not expected to be severe, but wind
gusts up to 45 mph and heavy downpours will be possible north of
highway 30.

Thunderstorms are expected to redevelop this afternoon over
eastern Iowa and move into northwest Illinois through early
evening. Wind shear and instability is likely to be sufficient for
severe storms with large hail and damaging winds. LOW level shear
is expected to be highest along the highway 20 corridor, where
there will be a low threat of tornadoes. While the atmosphere is
very moist and locally heavy rain is possible, storms should be
moving fast enough to limit any significant flash flood threat.

The Storm Prediction Center has a slight risk outlooked for areas
east of a line from Monticello, Iowa through the Quad Cities, to
Carthage Illinois. A marginal threat covers the rest of the
outlook area.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be required this afternoon and evening.

Sheets

In the hours before

Special weather statement, Aug 3, 9:22 AM CDT, 4 hours 54 minutes before
Special Weather Statement
National Weather Service Quad Cities IA/IL
922 AM CDT THU AUG 3 2017

IAC011-019-055-105-113-031515-
Buchanan-Benton-Jones-Delaware-Linn-
922 AM CDT THU AUG 3 2017

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT BUCHANAN...EASTERN
BENTON...WESTERN JONES...DELAWARE AND LINN COUNTIES UNTIL 1015 AM
CDT...

At 920 AM CDT, radar indicated strong thunderstorms were located
along a line extending from near Fairbank to near Urbana to Atkins.
Movement was east at 40 mph.

Wind gusts up to 50 mph are possible with these storms.

Locations impacted include...
Cedar Rapids, Independence, Anamosa, Vinton, Manchester, Marion,
Hiawatha, Mount Vernon, Monticello, Robins, Jesup, Center Point,
Lisbon, Fairfax, Atkins, Urbana, Central City, Fairbank, Springville
and Palo.

This includes Interstate 380 between mile markers 17 and 54.

Brief heavy rainfall is also occurring with these storms, and may
cause localized ponding on roads. Do not drive your vehicle through
flooded roadways.

LAT...LON 4195 9110 4195 9136 4193 9137 4193 9194
      4236 9206 4264 9208 4265 9130
TIME...MOT...LOC 1420Z 259DEG 33KT 4259 9204 4225 9193 4199 9186

HAASE
Special weather statement, Aug 3, 11:11 AM CDT, 3 hours 5 minutes before
Special Weather Statement
National Weather Service Quad Cities IA/IL
1111 AM CDT THU AUG 3 2017

ILC015-085-177-IAC045-097-105-031715-
Jo Daviess-Carroll-Stephenson-Jackson-Jones-Clinton-
1111 AM CDT THU AUG 3 2017

...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN JO DAVIESS...
NORTHERN CARROLL...SOUTHWESTERN STEPHENSON...JACKSON...SOUTHEASTERN
JONES AND NORTHERN CLINTON COUNTIES UNTIL 1215 PM CDT...

At 1110 AM CDT, a strong thunderstorm was located over Nashville, or
7 miles southwest of Maquoketa, moving east at 45 mph.

Winds in excess of 40 mph and dime size hail are possible with this
storm.

Locations impacted include...
Maquoketa, Mount Carroll, Savanna, Lanark, Preston, Hanover, Sabula,
Delmar, Wyoming, Oxford Junction, Lost Nation, Miles, Andrew,
Charlotte, Onslow, Welton, Monmouth, Springbrook, Toronto and
Andover.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 4206 8980 4186 9090 4194 9090 4195 9097
      4213 9102 4233 8989
TIME...MOT...LOC 1610Z 255DEG 38KT 4202 9079

HAASE
Special weather statement, Aug 3, 11:55 AM CDT, 2 hours 21 minutes before
Special Weather Statement
National Weather Service Quad Cities IA/IL
1155 AM CDT THU AUG 3 2017

ILC015-085-177-IAC097-031800-
Jo Daviess-Carroll-Stephenson-Jackson-
1155 AM CDT THU AUG 3 2017

...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN JO DAVIESS...
NORTHERN CARROLL...STEPHENSON AND SOUTHEASTERN JACKSON COUNTIES UNTIL
100 PM CDT...

At 1152 AM CDT, a strong thunderstorm was located over Green Island,
or 16 miles east of Maquoketa, moving east at 40 mph.

Winds in excess of 40 mph and half inch hail are possible with this
storm.

At 1130 am a wind gust of 43 mph was reported in Maquoketa, Iowa.

Locations impacted include...
Freeport, Mount Carroll, Savanna, Lena, Bellevue, Stockton, Lanark,
Preston, Hanover, Pearl City, Elizabeth, Shannon, Cedarville, Davis,
Sabula, Dakota, German Valley, Miles, Rock City and Ridott.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 4250 8940 4220 8940 4220 8969 4212 8969
      4203 9027 4203 9043 4226 9050 4250 8948
TIME...MOT...LOC 1652Z 253DEG 34KT 4213 9035

HAASE
Special weather statement, Aug 3, 2:16 PM CDT, 0 minutes before
Special Weather Statement
National Weather Service Quad Cities IA/IL
216 PM CDT THU AUG 3 2017

IAC019-055-032015-
Buchanan-Delaware-
216 PM CDT THU AUG 3 2017

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN BUCHANAN AND
NORTHERN DELAWARE COUNTIES UNTIL 315 PM CDT...

At 215 PM CDT, a strong thunderstorm was located over Stanley, or
near Oelwein, moving east at 25 mph.

Winds in excess of 40 mph are possible with this storm.

At 215 pm a trained spotter reported 40 mph winds in Stanley.

Locations impacted include...
Manchester, Edgewood, Hazleton, Lamont, Colesburg, Greeley, Aurora,
Dundee, Stanley, Oneida, Twin Bridges Park, Petersburg, Backbone
State Park and Jakway Park.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 4248 9116 4254 9190 4264 9190 4265 9116
TIME...MOT...LOC 1915Z 271DEG 23KT 4263 9180

HAASE

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 3, 9:22 AM CDTSpecial Weather StatementDVNBuchanan, Delaware, Linn53 min
Aug 3, 11:11 AM CDTSpecial Weather StatementDVNJackson64 min
Aug 3, 11:55 AM CDTSpecial Weather StatementDVNStephenson65 min
Aug 3, 3:42 PM CDTSpecial Weather StatementDVNHenderson48 min
Aug 3, 4:46 PM CDTSpecial Weather StatementDVNMercer44 min
Aug 3, 5:08 PM CDTSevere Thunderstorm WarningDVNMercer, Warren21 min
Aug 3, 5:11 PM CDTSpecial Weather StatementDVNHancock64 min
Aug 3, 5:43 PM CDTSpecial Weather StatementDVNMcDonough62 min
Aug 3, 6:06 PM CDTSevere Thunderstorm WarningDVNMcDonough39 min

Nearby

Special Weather Statements in Iowa, 2017Every 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.