Special Weather Statement, NWS Lincoln, IL

Area Forecast Discussion
National Weather Service Lincoln IL
1149 PM CDT Wed Aug 25 2021

.SYNOPSIS...
Issued at 251 PM CDT Wed Aug 25 2021

Hot and humid conditions will continue across the region the next
couple days, with periodic chances of showers and thunderstorms.
A few of the storms may be strong or locally severe, especially
in the afternoon and evening hours.

&&

.UPDATE...
Issued at 802 PM CDT Wed Aug 25 2021

Thunderstorms continue across central Illinois this evening,
though seeing signs of overall weakening trends this hour. An
outflow boundary has surged well ahead of a complex of storms,
reaching roughly Rushville to just north of Springfield then NE
through Le Roy as of 8 PM. Wind gusts of around 30 to 40 mph are
being reported with the gust front, and a few showers and storms
are briefly pulsing up along the boundary. Weak deep layer shear
and diminishing diurnal instability should keep the severe threat
in check for the remainder of the evening, and SPC has pulled the
marginal risk as a result. Storms may still briefly pulse up and
become strong with 3500 J/kg MLCAPE still in place, but slow storm
motions mean these storms quickly fall behind the outflow
boundary. Locally heavy rain is expected with the strongest cores
producing 1.5 inches per hour.

&&

.SHORT TERM...(This evening through Thursday)
ISSUED AT 251 PM CDT Wed Aug 25 2021

Outflow boundary that pushed through earlier today has washed out
without doing anything, though a boundary from convection in
Indiana has fired a few storms along the border near Danville and
Paris. Some new development southwest of the Quad Cities may be
associated with an earlier MCV, and will be curious to see how
much expansion takes place with it. NAM Nest was the only CAM that
hinted at that possibility with the morning model runs, and it
brings showers/storms across mainly the northwest third of the
forecast area through mid evening. Latest HRRR is more
disorganized and later with its development. Will mainly keep
evening PoP's in the 30% range for this activity with all the
uncertainty, with slight chances after midnight.

No significant pattern change is expected Thursday, with
boundaries still driving the rain chances. Outside of the storms,
another hot and humid day on tap. No changes will be done with the
heat headlines at this time.

.LONG TERM...(Thursday night through Wednesday)
ISSUED AT 251 PM CDT Wed Aug 25 2021

Several models indicate the potential for one or more MCS's to
move through the upper Mississippi Valley Thursday night. Most
take them just to our north, though the morning HRRR dives one
southeast into central Illinois Thursday evening. Will include
some 30-40% rain chances around Peoria northward for that. After
that, the general storm track pushes further north, with mostly
dry weather the first half of the weekend.

Forecast complications increase next week. Longer range models are
generally in agreement with a shortwave tracking across the upper
Mississippi Valley late Sunday, with shower and thunderstorm
chances increasing again. After that, the forecast will be driven
by a potential hurricane in the Gulf of Mexico. Models currently
have it arriving in Louisiana, though the GFS is much stronger
and slower with it. By Wednesday, its remnants are progged to be
in the vicinity of Arkansas. This would cause a bottleneck in
progression of the lingering front, though a stronger northeast
flow over our area would bring some welcome cooler conditions.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1144 PM CDT Wed Aug 25 2021

Showers and thunderstorms are ongoing across portions of the I-72
corridor, but expect these to be through the terminals by around
the time the 06Z TAFs go into effect. Light and variable winds are
expected overnight and may see some patchy fog, especially near
PIA which saw decent rainfall earlier today. Unstable conditions
will be in place through the day Thursday and cannot rule out
storms at any point, but have low confidence in any specifics.
Storms may reform mid to late Thursday morning along outflow south
and southwest of the terminals, then late in the evening and
overnight, another complex of storms may approach from the NW.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 7 PM CDT Thursday for ILZ040>042-047>057-
061>063-066>068-071>073.

&&

UPDATE...Deubelbeiss
SYNOPSIS...Geelhart
SHORT TERM...Geelhart
LONG TERM...Geelhart
AVIATION...Deubelbeiss

Hazardous Weather Outlook
National Weather Service Lincoln IL
311 PM CDT Wed Aug 25 2021

ILZ040>042-047>057-061>063-066>068-071>073-262015-
Cass-Christian-Clark-Clay-Coles-Crawford-Cumberland-Douglas-Edgar-
Effingham-Jasper-Lawrence-Logan-Macon-Mason-Menard-Morgan-
Moultrie-Richland-Sangamon-Schuyler-Scott-Shelby-
311 PM CDT Wed Aug 25 2021

...HEAT ADVISORY IN EFFECT UNTIL 7 PM CDT THURSDAY...

This Hazardous Weather Outlook is for portions of central
Illinois, east central Illinois, southeast Illinois and west
central Illinois.

.DAY ONE...TONIGHT...

Heat indices up to 105 are expected into early evening.

Scattered strong to severe storms are possible through tonight.
Damaging winds and locally heavy rainfall are the primary threats.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY...

Hot and humid conditions are expected again on Thursday with heat
indices between 100 and 105. Similar conditions will be present
Friday and Saturday, though afternoon heat indices look to be
around 100.

Isolated to scattered storms are possible at times through early
next week, including a few strong storms on Thursday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed through tonight.

ILZ027>031-036>038-043>046-262015-
Champaign-De Witt-Fulton-Knox-Marshall-McLean-Peoria-Piatt-Stark-
Tazewell-Vermilion-Woodford-
311 PM CDT Wed Aug 25 2021

...HEAT ADVISORY IN EFFECT UNTIL 7 PM CDT THIS EVENING...

This Hazardous Weather Outlook is for portions of central
Illinois, east central Illinois and west central Illinois.

.DAY ONE...TONIGHT...

Heat indices of 100 to 105 are expected into early evening.

Scattered strong to severe storms are possible through tonight.
Damaging wind gusts and locally heavy rainfall are the primary
threats.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY...

Hot and humid conditions are expected Thursday through Saturday
with heat indices between 95-100.

Isolated to scattered storms are possible at times through early
next week, including a few strong to severe storms on Thursday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed through tonight.

NMB

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LINCOLN IL
958 PM CDT WED AUG 25 2021

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

0957 PM     HEAVY RAIN       PEORIA INTL AIRPORT     40.66N 89.69W
08/25/2021  M1.36 INCH       PEORIA             IL   ASOS

&&

BMD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LINCOLN IL
959 PM CDT WED AUG 25 2021

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

0730 PM     HEAVY RAIN       GERMANTOWN HILLS        40.77N 89.47W
08/25/2021  M1.50 INCH       WOODFORD           IL   BROADCAST MEDIA

&&

BMD

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE LINCOLN IL
1001 PM CDT WED AUG 25 2021

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

0315 PM     HAIL             SCOTTLAND               39.80N 87.61W
08/25/2021  E1.00 INCH       EDGAR              IL   BROADCAST MEDIA

0345 PM     HEAVY RAIN       SCOTTLAND               39.80N 87.60W
08/25/2021  M1.25 INCH       EDGAR              IL   BROADCAST MEDIA

0427 PM     TSTM WND GST     2 N ALTONA              41.14N 90.16W
08/25/2021  E60 MPH          KNOX               IL   LAW ENFORCEMENT

0609 PM     TSTM WND GST     2 NNW PEORIA            40.74N 89.61W
08/25/2021  E60 MPH          PEORIA             IL   TRAINED SPOTTER

            ESTIMATED 60 MPH WINDS DOWNED POWER LINES
            NEAR LAKE AVE & UNIVERSITY ST.

0609 PM     HAIL             2 NNW PEORIA            40.74N 89.61W
08/25/2021  E1.00 INCH       PEORIA             IL   TRAINED SPOTTER

0730 PM     HEAVY RAIN       GERMANTOWN HILLS        40.77N 89.47W
08/25/2021  M1.50 INCH       WOODFORD           IL   BROADCAST MEDIA

0957 PM     HEAVY RAIN       PEORIA INTL AIRPORT     40.66N 89.69W
08/25/2021  M1.36 INCH       PEORIA             IL   ASOS

&&

Special Weather Statement
National Weather Service Lincoln IL
211 AM CDT Thu Aug 26 2021

ILZ051-260730-
Sangamon-
211 AM CDT Thu Aug 26 2021

...A strong thunderstorm will impact portions of west central
Sangamon County through 230 AM CDT...

At 211 AM CDT, Doppler radar was tracking a strong thunderstorm near
Chatham, or near Springfield, moving east at 20 mph.

HAZARD...Penny size hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to outdoor objects is possible.

This strong thunderstorm will be near...
  Chatham around 215 AM CDT.
  Springfield around 225 AM CDT.

This includes the following highways...
 Interstate 55 between mile markers 86 and 92.
 Interstate 72 between mile markers 89 and 98.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3968 8981 3976 8982 3979 8964 3965 8963
TIME...MOT...LOC 0711Z 267DEG 18KT 3973 8973

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...<30 MPH

37