Severe Thunderstorm Warning 137, NWS Lincoln, IL

669 
WWUS53 KILX 220619
SVSILX

Severe Weather Statement
National Weather Service Lincoln IL
119 AM CDT SAT JUL 22 2017

ILC183-220645-
/O.CON.KILX.SV.W.0137.000000T0000Z-170722T0645Z/
Vermilion-
119 AM CDT SAT JUL 22 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 145 AM CDT
FOR NORTHEASTERN VERMILION COUNTY...

At 118 AM CDT, a severe thunderstorm was located just east of 
Hoopeston, or 8 miles southwest of Talbot, moving southeast at 35 
mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

IMPACT...Expect damage to roofs, siding, and trees. 

Locations impacted include...
Hoopeston, Rossville and Alvin. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4048 8777 4049 8769 4049 8757 4046 8753
      4020 8753
TIME...MOT...LOC 0618Z 308DEG 29KT 4046 8760 

HAIL...<.75IN
WIND...60MPH
 
$$

Smith

798 
WWUS53 KILX 220636
SVSILX

Severe Weather Statement
National Weather Service Lincoln IL
136 AM CDT SAT JUL 22 2017

ILC183-220645-
/O.EXP.KILX.SV.W.0137.000000T0000Z-170722T0645Z/
Vermilion-
136 AM CDT SAT JUL 22 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN VERMILION COUNTY
WILL EXPIRE AT 145 AM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore the warning will be allowed to expire.

LAT...LON 4048 8777 4049 8769 4049 8757 4046 8753
      4020 8753
TIME...MOT...LOC 0635Z 316DEG 41KT 4032 8743 

$$

Smith

Area Forecast Discussion
National Weather Service Lincoln IL
1226 AM CDT Sat Jul 22 2017

.UPDATE...
Issued at 901 PM CDT Fri Jul 21 2017

Current forecast grids have already been updated once, but will be
making further adjustments to mainly pops/wx and severe watch. All
convection has remained north of the CWA this evening and based on
current radar trends looks like it will remain north of the CWA
remainder of the evening and possibly into the overnight hours.
However, additional precip is expected to develop along the
boundary out west and then move into northern IL again overnight.
Convection therefore is still possible in northern part of the CWA
overnight and will maintain some pops up there. Will be making
adjustment to evening pops across the north to account for current
trends. Update should be forthcoming.

&&

.SHORT TERM...(This evening through Saturday)
ISSUED AT 300 PM CDT Fri Jul 21 2017

19z/2pm surface analysis shows a 1006mb low over northeast
Nebraska...with a warm front extending eastward along the I-80
corridor. A large cluster of showers/thunderstorms has been
ongoing throughout the day northeast of the low over southeast
Minnesota into Wisconsin. As a result, an impressive instability
gradient has developed from north to south across Iowa, with
SBCAPEs of 5000-6000J/kg south of the boundary in southern Iowa.
A new cluster of storms has recently developed along this boundary
near the Iowa/Nebraska border. The HRRR has been consistently
showing convection firing in this area for the past several runs,
with the storms then developing/tracking E/SE along the boundary
into north-central Illinois this evening. Given the extreme
instability feeding into the storms, think they will quickly form
robust updrafts and become severe across central Iowa over the
next couple of hours. Once a cold pool can develop, the storms
will then begin racing E/SE along the instability axis into
north-central Illinois by mid to late evening. While the main push
will likely be along the I-80 corridor, think areas as far south
as I-74 will feel the impacts as well. Based on latest HRRR, have
introduced likely PoPs across the NW KILX CWA around Galesburg by
02z/9pm. Have then spread likely PoPs E/SE along/north of I-74
into the overnight hours. As the initial convective system pushes
east, a trialing band of showers/thunder will gradually sink
southward to I-72 toward dawn Saturday. Further south, have kept
the southern half of the CWA dry through the entire night. As it
stands now, think the biggest threat for severe weather and
potentially damaging wind gusts will focus along/north of I-74
between 9pm and 3am.

Scattered showers and thunderstorms will linger across the
northern CWA through mid-morning Saturday before dissipating.
May see some re-development along the cold front later in the
afternoon: however, subsidence in the wake of the morning
convective system may act to suppress widespread development
initially. As a result, will only carry low chance PoPs
during the afternoon. Areal coverage of convection will likely
increase across the southern half of the CWA Saturday evening as
the front sinks further south. High temperatures on Saturday will
once again climb well into the 90s...with peak afternoon heat
index readings of 105-115 degrees.

.LONG TERM...(Saturday night through Friday)
ISSUED AT 300 PM CDT Fri Jul 21 2017

Front will sink into the Ohio River Valley on Sunday: however, a
trailing weak trough axis may trigger isolated thunderstorms. Once
this feature passes, high pressure will build into the region
early next week...allowing a cooler/less humid airmass to take
control. High temperatures will drop into the lower to middle 80s
for both Monday and Tuesday, then will slowly climb back into the
middle to upper 80s by Wednesday. There are still some
discrepancies among the synoptic models later next week, but
consensus suggests the next significant chance for rain will hold
off until late Wednesday night through Friday as a slow-moving
frontal boundary comes into the picture.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1225 AM CDT Sat Jul 22 2017

Large convective complex from northeast Iowa into northern Indiana
has largely been tracking north of the central Illinois TAF sites
this evening. Outflow boundary from them should be passing through
KBMI very soon with some temporary northwest gusts of 20-30 knots
or so, and the TAF was amended for this possibility. Highest gusts
will likely be before 06Z, so the TAF starting at 06Z will only
have some north gusts of 20-25 knots for a couple hours. Have also
maintained the VCTS mention at KPIA/KBMI from about 08-14Z as the
storms track southeast from Iowa. In addition, have added LLWS
mention during that time for these two sites with a lower level
jet ramping up just south of the convection.

After that, mainly quiet conditions expected through the
afternoon. A cold front will be moving through late afternoon and
evening between about 22-03Z. Some scattered storms possible along
this boundary, but too uncertain to add at this point.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Excessive Heat Warning until 8 PM CDT this evening for
ILZ027>029-036-037-040>042-047>054-061-062-066>068-071>073.

Heat Advisory until 8 PM CDT this evening for ILZ030-031-038-
043>046-055>057-063.

&&

UPDATE...Auten
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Geelhart

Hazardous Weather Outlook
National Weather Service Lincoln IL
414 PM CDT Fri Jul 21 2017

ILZ030-031-038-043>046-055>057-063-221100-
Champaign-Clark-Coles-De Witt-Douglas-Edgar-Marshall-McLean-Piatt-
Vermilion-Woodford-
414 PM CDT Fri Jul 21 2017

...HEAT ADVISORY IN EFFECT UNTIL 8 PM CDT SATURDAY...

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

.DAY ONE...TONIGHT...

The threat for severe storms will increase late this evening into
the early morning hours of Saturday, especially along and north
of the Interstate 74 corridor. Damaging wind gusts will be the
primary threat tonight.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY...

Hot and humid conditions will prevail Saturday with Heat Index
values of 105 to 110 during the afternoon. Slightly cooler and
less humid air will filter in on Sunday.

Scattered thunderstorms may redevelop Saturday afternoon into
early Saturday night as a cool front sinks into the area. Some of
the storms could become severe on Saturday...with damaging wind
gusts, large hail, and torrential downpours possible.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed tonight into the early morning
hours of Saturday, especially in areas along and north of the
Interstate 74 corridor.

ILZ027>029-036-037-041-042-221100-
Fulton-Knox-Logan-Mason-Peoria-Stark-Tazewell-
414 PM CDT Fri Jul 21 2017

...EXCESSIVE HEAT WARNING IN EFFECT UNTIL 8 PM CDT SATURDAY...

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

.DAY ONE...TONIGHT...

Isolated thunderstorms will be possible tonight, with the main
threat for severe storms along and north of I-74. A few storms in
our area may produce strong wind gusts and torrential rainfall
tonight.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY...

Hot and humid conditions will prevail through Saturday. Afternoon
heat index values will peak around 110 degrees before slightly
cooler and less humid air moves in on Sunday.

The thunderstorms may become more numerous late Saturday
afternoon into Saturday night as a cold front sinks into the area.
Some of the storms could become severe on Saturday...with
damaging wind gusts, large hail, and torrential downpours
possible.

.SPOTTER INFORMATION STATEMENT...

Limited spotter activation may be needed later this afternoon.

ILZ040-047>054-061-062-066>068-071>073-221100-
Cass-Christian-Clay-Crawford-Cumberland-Effingham-Jasper-Lawrence-
Macon-Menard-Morgan-Moultrie-Richland-Sangamon-Schuyler-Scott-
Shelby-
414 PM CDT Fri Jul 21 2017

...EXCESSIVE HEAT WARNING IN EFFECT UNTIL 8 PM CDT SATURDAY...

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

.DAY ONE...TONIGHT...

An isolated thunderstorm will be possible tonight. Although no
organized severe weather is expected, a few of the storms will be
capable of producing gusty winds, torrential rainfall and frequent
lightning.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY...

Hot and humid conditions will prevail through Saturday. Afternoon
heat index values will peak near 110 degrees before slightly
cooler and less humid air filters in on Sunday.

Thunderstorms may become more widespread ahead of a weak cold
front later Saturday afternoon into Saturday night. Some of the
storms could become strong on Saturday...with gusty winds, hail,
and torrential downpours possible.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated through tonight.

Bak

Special Weather Statement
National Weather Service Lincoln IL
1229 AM CDT SAT JUL 22 2017

ILZ038-044>046-220615-
Vermilion-Piatt-McLean-Champaign-
1229 AM CDT SAT JUL 22 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN VERMILION AND NORTHERN
CHAMPAIGN COUNTIES UNTIL 115 AM CDT...

At 1228 AM CDT, Doppler radar was tracking a strong thunderstorm near
Cissna Park, or 7 miles west of Claytonville, moving southeast at 30
mph.

Winds in excess of 40 mph will be possible with this storm.

Locations impacted include...
Champaign, Danville, Rantoul, Urbana, Mahomet, Hoopeston, Fisher,
Rossville, Thomasboro, Gifford, Potomac, Rankin, Lake Of The Woods,
Bismarck, Ludlow, Royal, Henning, Foosland, Dewey and Flatville.

This includes the following highways...
 Interstate 57 between mile markers 237 and 257.
 Interstate 74 between mile markers 169 and 179.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4014 8846 4040 8847 4040 8794 4049 8793
      4049 8753 4014 8753
TIME...MOT...LOC 0528Z 309DEG 28KT 4054 8796

Smith