Severe Thunderstorm Warning 69, NWS Quad Cities, IA

788 
WWUS53 KDVN 172234
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
534 PM CDT WED MAY 17 2017

ILC161-172243-
/O.CAN.KDVN.SV.W.0069.000000T0000Z-170517T2315Z/
Rock Island IL-
534 PM CDT WED MAY 17 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN ROCK ISLAND
COUNTY IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved north 
out of the warned area. Therefore, the warning has been cancelled.

A tornado watch remains in effect until 1100 PM CDT for east central
Iowa.

LAT...LON 4152 9080 4161 9106 4203 9085 4187 9034
TIME...MOT...LOC 2233Z 208DEG 40KT 4170 9082 

$$

IAC031-045-139-163-172315-
/O.CON.KDVN.SV.W.0069.000000T0000Z-170517T2315Z/
Cedar IA-Scott IA-Muscatine IA-Clinton IA-
534 PM CDT WED MAY 17 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM CDT
FOR SOUTHEASTERN CEDAR...NORTHWESTERN SCOTT...NORTHEASTERN MUSCATINE
AND WESTERN CLINTON COUNTIES...

At 533 PM CDT, a severe thunderstorm was located 7 miles north of
Walcott, or 7 miles northeast of Durant, moving northeast at 45 mph.

HAZARD...Ping pong ball size hail and 60 mph wind gusts. 

SOURCE...Trained weather spotters. 

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees. 

Locations impacted include...
Durant, DeWitt, Wilton, Walcott, Long Grove, Lowden, Wheatland, Grand
Mound, Lost Nation, Calamus, Bennett, Donahue, Welton, Toronto,
Dixon, Stockton, Maysville, New Liberty, Malone and Camp Liberty.

This includes Interstate 80 in Iowa between mile markers 271 and 289.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
sturdy building.

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows.

&&

A tornado watch remains in effect until 1100 PM CDT for east central
Iowa.

LAT...LON 4152 9080 4161 9106 4203 9085 4187 9034
TIME...MOT...LOC 2233Z 208DEG 40KT 4170 9082 

TORNADO...POSSIBLE
HAIL...1.50IN
WIND...60MPH
 
$$

12

176 
WWUS53 KDVN 172241
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
541 PM CDT WED MAY 17 2017

IAC139-172251-
/O.CAN.KDVN.SV.W.0069.000000T0000Z-170517T2315Z/
Muscatine IA-
541 PM CDT WED MAY 17 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN MUSCATINE COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved north 
out of the warned area. Therefore, the warning has been cancelled.

A tornado watch remains in effect until 1100 PM CDT for east central
Iowa.

LAT...LON 4163 9067 4169 9101 4203 9085 4187 9034
TIME...MOT...LOC 2241Z 209DEG 39KT 4177 9076 

$$

IAC031-045-163-172315-
/O.CON.KDVN.SV.W.0069.000000T0000Z-170517T2315Z/
Cedar IA-Scott IA-Clinton IA-
541 PM CDT WED MAY 17 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM CDT
FOR EAST CENTRAL CEDAR...NORTHWESTERN SCOTT AND WESTERN CLINTON
COUNTIES...

At 541 PM CDT, a severe thunderstorm was located near Calamus, or 14
miles northeast of Durant, moving northeast at 45 mph.

HAZARD...60 mph wind gusts and half dollar size hail. 

SOURCE...Radar indicated. 

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees. 

Locations impacted include...
DeWitt, Long Grove, Lowden, Wheatland, Grand Mound, Lost Nation,
Calamus, Bennett, Donahue, Welton, Toronto, Dixon, Maysville, New
Liberty, Malone, Camp Liberty, Bennett Park, Big Rock, Elvira and
Sherman Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
sturdy building.

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows.

&&

A tornado watch remains in effect until 1100 PM CDT for east central
Iowa.

LAT...LON 4163 9067 4169 9101 4203 9085 4187 9034
TIME...MOT...LOC 2241Z 209DEG 39KT 4177 9076 

TORNADO...POSSIBLE
HAIL...1.25IN
WIND...60MPH
 
$$

12

738 
WWUS53 KDVN 172254
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
554 PM CDT WED MAY 17 2017

IAC031-045-163-172304-
/O.CAN.KDVN.SV.W.0069.000000T0000Z-170517T2315Z/
Cedar IA-Scott IA-Clinton IA-
554 PM CDT WED MAY 17 2017

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL CEDAR...
NORTHWESTERN SCOTT AND WESTERN CLINTON COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning has been cancelled.  However small hail and
gusty winds are still possible with this thunderstorm.

A tornado watch remains in effect until 1100 PM CDT for east central
Iowa.

LAT...LON 4163 9067 4169 9101 4203 9085 4187 9034
TIME...MOT...LOC 2250Z 208DEG 40KT 4190 9066 

$$

12

Area Forecast Discussion
National Weather Service Quad Cities IA IL
224 PM CDT Wed May 17 2017

.SYNOPSIS...
Issued at 221 PM CDT Wed May 17 2017

Abbreviated early issuance AFD to get ready for convective event.
Water vapor showing neg tilted upper wave on track acrs southeastern
Neb. After potentail convective severe event this afternoon and
evening, a reprieve with cooler conditions on Thu. Then the next
main upstream large cut-off upper low will roll out to the upper
Midwest for a wet end to the week and start to the weekend.
Generally cooler Sunday into earlier next week, with another wave
digging from the northwest for another precip event toward mid next
week.

&&

.SHORT TERM...(This Evening through Thursday)
ISSUED AT 221 PM CDT Wed May 17 2017

Will have to watch for isolated to sctrd elevated storms with
hail potential ahead of the "main show" for the rest of the
afternoon, but the main severe weather event currently gathering
steam/"bubbling" in sfc pressure falls max over the MO RVR
Valley. Strong wing of lift into current mesoanalysis-indicated
already strongly sheared environment in place acrs the local area,
supportive of enhanced severe weather risk acrs the area
especially along and west of the MS RVR. Most of latest run
HiRes/CAM's continue to suggest an arching wing or two of broken
line of supercells, mixed with a few strong convective clusters,
moving rapidly at 50-60 MPH in from the west- southwest mainly
after 21z, with prime impact window from 5 PM to 8 or 9 PM CDT
before the brunt of the activity blows eastward. Again speed of
storms to complicate matters and increase danger aspect. Current
CAPEs of 1000-1500 J/KG acrs the region may increase a bit more
through early evening, while brunt of Cap/EML starts to migrate
eastward. This should be adequate for such strong shear profiles
to work with for all modes of severe weather, with tornadoes and
large hail the prime threats. But lingering concern that limited
CAPE for such strong shear profiles, may actually limit a higher
end severe weather event such as if we had 3000+ CAPEs.

The tornado threat may be limited to the initial incoming line as
long as llvl winds have some type of southeasterly direction
component, but then switch to more hail and damaging winds, as llvl
ambient environmental winds go south-southwest making for a more
uniform vertical profile, but still very high in speed shear.

Some isolated to sctrd showers and storms may linger acrs the
northern half of the CWA after the main line exits off to the east-
northeast through midnight, but then mainly dry into Thu morning or
just some wrap-around showers in the far north as upper level
cyclone pivots acrs northern WI and induces wrap-around.

Thu...after wrap around showers decrease in the north, this day
mainly dry and cooler in between two upper cyclones, with varying
amounts of cloud cover. LLVL baroclinicity aligns and tightens along
and south of the DVN CWA into the evening, with northeast post-
frontal boundary layer winds keeping temps in the 60s to low 70s
acrs much of the area.    ..12..

.LONG TERM...(Thursday Night through next Wednesday)
ISSUED AT 221 PM CDT Wed May 17 2017

Active weather pattern to continue through the period with chances
of rain and thunderstorms through the beginning of the weekend and
then again midweek next week.  Previously discussed issues with
model inconsistency still remains with this package.  This, along
with the threat for severe weather today has led to heavy use of
blended guidance for the long term.  Overall agreement in the large
scale pattern through the period means that the mesoscale details
need to be worked out and thus lead to most of uncertainty
throughout the period.   Gibbs

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
ISSUED AT 1241 PM CDT Wed May 17 2017

Brisk southerly sfc winds gusting over 30 KTS along with passing
mainly VFR clouds will be the main story this afternoon before the
main line of storms is expected to move into the local area from
the southwest later this afternoon and evening. An isolated storm to
wdly sctrd storms, though, is possible over the area ahead of the
main line, thus may keep VCNTY wording although that may be heavy
handed if current RADAR trends remain consistent. Have tried to
time a 1-2 hour window when a passing line of severe storms will
move northeastward through the TAF sites again during late
afternoon into early-mid evening. Then VCNTY for a few hours for
lingering isolated to sctrd storms behind the main line through
mid to late evening, then trend dry from midnight into Thu
morning. Sfc winds veering to the west at 10-20 KTS late tonight
into Thu morning, with cigs lowering to low VFR to MVFR in the main
low pressure storm system's wrap around cloud deck.   ..12..

&&

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

SYNOPSIS...12
SHORT TERM...12
LONG TERM...Gibbs
AVIATION...12

Hazardous Weather Outlook
National Weather Service Quad Cities IA IL
302 AM CDT Wed May 17 2017

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-180815-
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-
302 AM CDT Wed May 17 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...TONIGHT

Scattered thunderstorms are expected this morning. The main
threats are lightning and hail to penny size.

More widespread thunderstorms are expected this afternoon and
evening. Fast-moving storms could produce damaging winds around 70
mph and tornadoes. A secondary threat is large hail.

A south wind will gust around 40 mph this afternoon. Drivers of
high profile vehicles should use caution.

Area rivers are experiencing flooding. Please see the
latest Flood Statements and Flood Warnings for details.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

There is a risk of thunderstorms late Thursday night through
Saturday evening. It is too early to determine the severe weather
risk.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is expected between 2 PM and 10 PM CDT today.

RP Kinney/08

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
513 PM CDT WED MAY 17 2017

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

0452 PM     HAIL             SSE GRANDVIEW           41.28N 91.19W
05/17/2017  M1.00 INCH       LOUISA             IA   TRAINED SPOTTER

            DELAYED REPORT, TIME ESTIMATED

&&

PETERS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
515 PM CDT WED MAY 17 2017

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

0420 PM     TSTM WND DMG     WELLMAN                 41.47N 91.84W
05/17/2017                   WASHINGTON         IA   LAW ENFORCEMENT

            TIME ESTIMATED - OUTBUILDINGS, SHED, WINDOWS AND ROOFS
            DAMAGED

&&

TES

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
516 PM CDT WED MAY 17 2017

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

0514 PM     HAIL             3 NE MUSCATINE          41.45N 91.04W
05/17/2017  M0.88 INCH       MUSCATINE          IA   TRAINED SPOTTER

&&

GROSS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
521 PM CDT WED MAY 17 2017

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

0420 PM     TSTM WND DMG     1 E RUBIO               41.22N 91.91W
05/17/2017                   WASHINGTON         IA   TRAINED SPOTTER

            TIME ESTIMATED - SEVERAL TREES DAMAGED. BOARDS BLOWN OFF
            RAILROAD WALKWAY, GROUND COVERED WITH LEAVES

&&

TES

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
522 PM CDT WED MAY 17 2017

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

0511 PM     HAIL             3 NE MUSCATINE          41.46N 91.03W
05/17/2017  M1.00 INCH       MUSCATINE          IA   TRAINED SPOTTER

&&

GROSS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
523 PM CDT WED MAY 17 2017

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

0523 PM     HAIL             3 S DURANT              41.56N 90.91W
05/17/2017  M1.75 INCH       MUSCATINE          IA   TRAINED SPOTTER

&&

TES