Special Weather Statement, NWS Quad Cities, IA

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1228 AM CDT Sat Jun 19 2021

...SHORT TERM AND 06z AVIATION UPDATE...

.SYNOPSIS...
Issued at 1223 AM CDT Sat Jun 19 2021

An active night is unfolding across most of eastern Iowa, northwest
Illinois and far northeast Missouri. Showers and thunderstorms have
developed as a result of interactions of a low-level jet, stalled
cold front, upper level jet streak entrance region and an
approaching short wave from the Dakotas. Reports of large hail up to
golf ball size, wind damage and torrential rain have been received
from the strongest cores, and will continue to be a concern over
the next few hours.

&&

.SHORT TERM...(Today and Tonight)
ISSUED AT 1223 AM CDT Sat Jun 19 2021

[Key Messages]

*Showers and strong/severe storms continue through early morning
before exiting the area.

*Dry Saturday daytime before precipitation chances increase
overnight into Sunday

[Discussion]

Expect showers and storms to continue to move south and east along
the favored convergence zone on the nose of the LLJ and cold front
through the early morning. Instability of around 2000-3500 J/kg
aloft and mid-level lapse rates favored around 7-9 C/km will ensure
large hail remains a threat. Storms that manage to become surface
based due to cold pools and outflow boundary interactions will also
be capable of producing damaging wind gusts.

These storms should exit the area around 10-12z, and will give way
to a relatively quiet Saturday as surface high pressure builds
across the area. Despite the cold front passing to the south,
temperatures will remain on the warm side with daytime highs
forecast to climb into the mid 80s to low 90s.

A renewed round of showers and storms will arrive across the area
late Saturday night into early Sunday. This looks to be the
remnants of severe convection that will fire in Nebraska/Kansas
Saturday evening with convergence into an MCS in the overnight
hours. Confidence on this complex maintaining severe criteria is
low, but chances for this look to return for the beginning of the
long term period with the approach of a cold front from the west.

.LONG TERM...(Saturday Night through Friday)
ISSUED AT 302 PM CDT Fri Jun 18 2021

Sunday into Sunday night may feature another round of severe
storms, then quieter weather with cooler temperatures and lower
humidity looks to be the rule through midweek.

Saturday night into Sunday, a couple shortwaves are shown directly
impacting the area bringing one round of thunderstorms late
Saturday night into Sunday and another late Sunday into Sunday
night. This second system looks stronger and will drive a strong
cold front through the area, presenting a risk for thunderstorms,
possibly severe. SPC has a broad Marginal risk in place for Sunday
and our forecast has likely POPS across the north for Sunday and
over much of the area for Sunday night. Highs in the upper 80s to
around 90 Sunday will be replaced by 70s with much lower humidity
Monday and Tuesday.

Wednesday begins a transition to a more active pattern with warmer
temperatures and thunderstorm chances Thursday and Friday.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday Night)
ISSUED AT 1223 AM CDT Sat Jun 19 2021

Concerns over the next 6 hours mainly for KMLI and KBRL as a large
complex of showers and strong/severe thunderstorms moves across the
area. Large hail and damaging wind gusts have been reported with the
strongest cores, and will continue to be a threat for these
terminals until storms exit the area around 10-12z. After this, VFR
conditions are expected with winds shifting to the north while
remaining under 10 knots.

&&

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

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

Hazardous Weather Outlook
National Weather Service Quad Cities IA IL
757 PM CDT Fri Jun 18 2021

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-200100-
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-
757 PM CDT Fri Jun 18 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...TONIGHT

Severe storms are possible tonight, especially along and south of
Interstate 80, where the Storm Prediction Center has an Enhanced
Risk for severe storms. The initial storm hazards will be very large
hail and damaging winds with scattered storms this evening.
Storms later tonight are expected to have primarily a risk for
damaging winds. Heavy rainfall will also be possible, which could
lead to flash flooding.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

Thunderstorms are expected late Saturday night, Sunday and Sunday
night. The Storm Prediction Center has outlooked a Marginal Risk
for severe weather across the forecast area Sunday. The main
threat from these storms will be large hail Sunday morning, then
large hail and damaging winds with storms along an ahead of a cold
front that will pass through the area late Sunday and Sunday
night.

.SPOTTER INFORMATION STATEMENT...

Storm spotter activation will likely be needed tonight in
southeast Iowa, northeast Missouri and west central Illinois.

DLS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1152 PM CDT FRI JUN 18 2021

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

1152 PM     HAIL             WASHINGTON              41.29N 91.69W
06/18/2021  M0.75 INCH       WASHINGTON         IA   TRAINED SPOTTER

            RELAYED BY HAM RADIO OPERATOR.

&&

PS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1202 AM CDT SAT JUN 19 2021

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

1150 PM     HEAVY RAIN       OQUAWKA                 40.94N 90.95W
06/18/2021  M1.33 INCH       HENDERSON          IL   PUBLIC

            TOTAL RAINFALL SO FAR.

&&

PS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1232 AM CDT SAT JUN 19 2021

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

1100 PM     TSTM WND DMG     MONMOUTH                40.92N 90.64W
06/18/2021                   WARREN             IL   TRAINED SPOTTER

            2 LARGE TREE LIMBS BLOWN DOWN.

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1232 AM CDT SAT JUN 19 2021

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

1105 PM     TSTM WND DMG     MONMOUTH                40.92N 90.64W
06/18/2021                   WARREN             IL   TRAINED SPOTTER

            2 LARGE TREE LIMBS BLOWN DOWN.

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1248 AM CDT SAT JUN 19 2021

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

1217 AM     HAIL             4 NE KEOTA              41.41N 91.89W
06/19/2021  M1.50 INCH       WASHINGTON         IA   PUBLIC

            REPORT AND PICTURE VIA SOCIAL MEDIA.

&&

PS

Special Weather Statement
National Weather Service Quad Cities IA/IL
128 AM CDT Sat Jun 19 2021

ILC071-131-187-IAC057-115-190830-
Henderson-Warren-Mercer-Des Moines-Louisa-
128 AM CDT Sat Jun 19 2021

...MINOR FLOODING WILL AFFECT NORTHEASTERN HENDERSON...NORTHERN
WARREN...SOUTHERN MERCER...NORTHERN DES MOINES AND SOUTHERN LOUISA
COUNTIES UNTIL 330 AM CDT...

At 126 AM CDT, radar indicated heavy rain had fallen along a line
extending from near Winfield to near Knoxville.

Locations impacted include...
Monmouth, Wapello, Columbus Junction, Oquawka, Mediapolis, Morning
Sun, Kirkwood, New Boston, Keithsburg, Columbus City, Little York,
Rozetta, Seaton, Oakville, Toolesboro, Ogle, Kossuth, Alexis,
Coldbrook and Bald Bluff.

Torrential rainfall is also occurring with these storms. Minor
flooding of low lying areas, creeks, streams and urban areas is
possible. If you encounter water over a roadway, do not drive through
it.

LAT...LON 4103 9137 4116 9137 4116 9140 4128 9140
      4107 9044 4080 9044
TIME...MOT...LOC 0626Z 309DEG 4KT 4116 9135 4090 9032

Gibbs