Flash Flood Warning 23, NWS Lincoln, IL

Area Forecast Discussion
National Weather Service Lincoln IL
1224 PM CDT Wed Jun 19 2019

.UPDATE...
Issued at 1110 AM CDT Wed Jun 19 2019

Morning update featured an expansion of the Flash Flood Watch
northward to include Schuyler, Fulton and Mason counties. A line
of morning storms has already produced rainfall rates of 4"/hour
at times in western Schuyler Co. where a Flash Flood Warning is in
effect. Additional updates were to the PoP/Wx grids for the late
afternoon and evening time frame, due to a convectively-enhanced
MCV/shortwave coming out of Missouri that the models are having
a hard time resolving. Mainly increased PoPs to categorical over a
larger area of central IL for a longer time this evening.

Severe potential still present in our southeast counties for this
afternoon into evening. MLCAPE values climb to 2500 J/kg with low
LCLs around 650m. Mainly narrow CAPE through a deep layer, so
updraft intensity will not be excessively strong. However, plenty
of support for large hail. DCAPE values marginal around 650 J/kg,
but a few downbursts could develop in the stronger storms. Tornado
potential is generally low, but can't rule out an isolated spin-
up.

Severe threat time looks to be mainly 2 pm to 8 pm. Heavy rain
and additional flash flooding appear likely, due to PWATs around
2". These storms will be able to drop rain at very high rainfall
rates, possibly between 4-6"/hour for short periods of time.

Update forecast info is already available.

&&

.SHORT TERM...(Today and tonight)
ISSUED AT 243 AM CDT Wed Jun 19 2019

Well another night of fighting the PoPs and QPF for the upcoming
system today. A weak Low pressure system is shifting through
northern Missouri this morning, and will continue to track ENE.
This will send the Low through north central Illinois today,
bringing yet again the chance for flash flooding to occur. In
collaboration with WPC overnight, a MDT flash flooding risk was
extended into the CWA along the I-70 corridor. This was due to
excessive rainfall the past couple of days in that region, leading
to lower FFG rates. Locations north of I-70 and south of I-72 will
be the main focus for today's heavy rainfall, therefore a new FFA
was issued to cover this area from 08z today through 18z Thursday.
I added a county buffer to the north end of the Watch, in case
there is a slight shift northward of the Low track.

Shower and storms are expected to slide into the area this
morning, with current radar indicating some development south of
the St. Louis metro. This band will track into southeastern
Illinois around 12z. However, the main show will not arrive until
midday, overspreading the CWA throughout the afternoon. Some
storms this afternoon/evening could become strong to severe, with
training expected as overall speed is slow. Models have good
agreement on the track through central Illinois, however they lack
confidence in the amount of precipitation. The NAM is the major
outlier, hinting at upwards of 4 inches of precip...while a
majority of the other models have 1.50-2.00 inches. The main axis
of rainfall will occur between I-70 and I-72, while locations
outside of this will range from 0.50-1.50 inches.

Clear skies in northern Illinois this morning will give way to
returning clouds through the morning, while southern Illinois will
remain mostly cloudy throughout today. Some warming will occur
today, as the stalled out frontal boundary shifted northward
during the evening and overnight. But along with this warming, dew
points will also increase into the mid 60s to low 70s.

Cooler temperatures will prevail today and Thursday, before a
warmup this weekend to more summer-like conditions.

.LONG TERM...(Thursday through Tuesday)
ISSUED AT 243 AM CDT Wed Jun 19 2019

As the Low pulls out of the area Thursday, rain will shift
eastward into the Ohio Valley by the afternoon. As this exits, a
Low pressure system in western Canada will drop into the northern
Rockies. As a result, a weather pattern will redevelop...bringing
the return of a building ridge to the area Thursday evening. Even
though a weak ridge, it will dry out the area Thursday night into
Friday morning.

Looking at the end of the work week and this upcoming weekend,
unfortunately the wet weather pattern remains. The Low will track
eastward through Canada, carrying another wave system through the
Plains Friday morning and into the Midwest Friday afternoon. This
system will not drop far enough into the US to bring a cold front
through the area. So again, heading through the weekend, the
system will drape a frontal boundary east-west across the area.
This will allow for another set of waves to ride along, bringing
more rain to the Midwest.

This weekend will feature a more summer-like pattern, with temps
in the 80s, with dewpoints in the upper 60s and 70s. Rainfall
totals this weekend have decreased, as values are from 0.75-2.50
inches. This is still preliminary, and expected to change over the
next 24-48 hours once models get through today's event.

Looking ahead to the CPC outlooks, precipitation is expected to
remain above average through the remainder of June, with normal to
slightly above normal temperatures around Illinois.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1224 PM CDT Wed Jun 19 2019

An MCV lifting across central Illinois this afternoon is
triggeringa line of showers/storms from NW to SE. The line has
embedded periods of heavy rain, which has been reducing visibility
to 3/4SM in heavy rain at times. Ceilings have briefly dipped to
MVFR during any storms to this point, and that potential will
increase with the next wave of rain and storms for later this
afternoon into evening. An extended period of rain/storm potential
will be present through this evening, as an upper level wave
progresses from west to east across Illinois. Storm chances will
diminish by mid to late evening, with lingering rain showers and
lowering ceilings forecast by the CAMs. A solid MVFR cloud deck is
projected to start out the day on Thursday, as winds turn
northwest.

Winds this afternoon will have most areas seeing east to
southeast flow. As the low pushes across IL, winds will back to
the northeast, but sustain below 10kt in general during that time.
As the storm and rain chances subside later tonight into Thursday,
winds will become N to NW with time.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through Thursday afternoon for ILZ036-040>057-
061>063-066>068-071>073.

&&

UPDATE...Shimon
SHORT TERM...Baker
LONG TERM...Baker
AVIATION...Shimon

Hazardous Weather Outlook
National Weather Service Lincoln IL
1156 AM CDT Wed Jun 19 2019

ILZ027>031-037-038-201100-
Knox-Marshall-McLean-Peoria-Stark-Tazewell-Woodford-
1156 AM CDT Wed Jun 19 2019

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

.DAY ONE...THIS AFTERNOON AND TONIGHT...

Showers and thunderstorms are expected today and tonight.
Severe weather is not anticipated.

Moderate flooding on the Illinois River will continue from Havana
downstream, while minor flooding continues for portions of the
river upstream.

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

Periodic showers and thunderstorms are possible Friday through
Tuesday. There is a risk for severe thunderstorms Friday. It is
still too early to pinpoint any specific severe weather risks
during the weekend into next week. Locally heavy rainfall will be
possible.

Moderate flooding on the Illinois River will continue from Havana
downstream, while minor flooding continues for portions of the
river upstream.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed through tonight.

ILZ036-040>057-061-201100-
Cass-Champaign-Christian-Coles-De Witt-Douglas-Edgar-Fulton-Logan-
Macon-Mason-Menard-Morgan-Moultrie-Piatt-Sangamon-Schuyler-Scott-
Shelby-Vermilion-
1156 AM CDT Wed Jun 19 2019

...FLASH FLOOD WATCH IN EFFECT THROUGH THURSDAY AFTERNOON...

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

.DAY ONE...THIS AFTERNOON AND TONIGHT...

Showers and thunderstorms are expected today and tonight.
Widespread severe weather is not anticipated: however,
thunderstorms with excessive rainfall rates may produce localized
flash flooding.

Moderate flooding on the Illinois River will continue from Havana
downstream, while minor flooding continues for portions of the
river upstream.

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

Periodic showers and thunderstorms are possible Friday through
Tuesday. There is a risk for severe thunderstorms Friday. It is
still too early to pinpoint any specific severe weather risks
during the weekend into next week. Locally heavy rainfall will be
possible.

Moderate flooding on the Illinois River will continue from Havana
downstream, while minor flooding continues for portions of the
river upstream.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed through tonight.

ILZ062-063-066>068-071>073-201100-
Clark-Clay-Crawford-Cumberland-Effingham-Jasper-Lawrence-Richland-
1156 AM CDT Wed Jun 19 2019

...FLASH FLOOD WATCH IN EFFECT THROUGH THURSDAY AFTERNOON...

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

.DAY ONE...THIS AFTERNOON AND TONIGHT...

Showers and thunderstorms are expected today and tonight.
Some of the storms could become severe, with damaging wind gusts
and large hail being the main threats. Localized flash flooding
due to excessive rainfall rates will be possible as well.

Minor flooding will continue on portions of the Wabash, Little
Wabash, and Embarras Rivers.

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

Periodic showers and thunderstorms are possible Friday night
through Tuesday. There is a marginal risk for severe
thunderstorms Friday night. It is still too early to pinpoint any
specific severe weather risks during the weekend into next week.
Locally heavy rainfall will be possible.

Minor flooding will continue on portions of the Wabash, Little
Wabash, and Embarras Rivers for several days.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed this afternoon and evening.

Barnes