Dense Fog Advisory 21, NWS Lincoln, IL

450 
WWUS73 KILX 021454
NPWILX

URGENT - WEATHER MESSAGE
National Weather Service Lincoln IL
954 AM CDT Thu Nov 2 2017

ILZ027-028-030-021600-
/O.EXP.KILX.FG.Y.0021.000000T0000Z-171102T1500Z/
Knox-Stark-Marshall-
Including the cities of Galesburg, Toulon, and Lacon
954 AM CDT Thu Nov 2 2017

...DENSE FOG ADVISORY WILL EXPIRE AT 10 AM CDT THIS MORNING...

Areas of dense fog continue another hour or so, but the fog will
be gradually thinning across the area.

$$

Geelhart

Area Forecast Discussion
National Weather Service Lincoln IL
1151 PM CDT Wed Nov 1 2017

.UPDATE...
Issued at 904 PM CDT Wed Nov 1 2017

Skies are overcast and patchy fog covers the whole area. A couple
of sites are reporting precip and based on surrounding radars, I'm
sure light rain or drizzle is occurring at other locations, just
not getting reported. Current forecast has light rain/drizzle over
eastern half of the area with patchy fog over the whole area the
remainder of the night. Current forecast looks ok but will send an
update with hopes that temp wording will be steady or slowly
rising overnight.

&&

.SHORT TERM...(This evening through Thursday)
ISSUED AT 310 PM CDT Wed Nov 1 2017

The evening forecast will be dominated by a persistent low level
southerly flow into central Illinois, as a warm frontal
circulation develops to our northwest, centered from across NW
Missouri and into NW Illinois. There appears to be increasing
evidence in the low level thermal and moisture profiles that low
clouds, fog, and patchy drizzle will be possible overnight
tonight, as synoptic scale lift persists in the warm advection
flows. The blanket of clouds will limit diurnal cooling, with
nearly steady or slowly rising temps in the mid 40s to low 50s. A
cloudy but mild day is on tap for Thursday, with scattered showers
developing by afternoon, if not continuing through the morning
into the afternoon in some areas east of I-55. Steady southerly
warm air advection flows will help produce mild high temps ranging
from around 60 near Galesburg, to the upper 60s south of I-72.

.LONG TERM...(Thursday night through Wednesday)
ISSUED AT 310 PM CDT Wed Nov 1 2017

Thursday night will see ongoing showers east of I-55, as a
surface wave progresses to the NE along the warm front, and exits
into Indiana. Precip chances will end after midnight, with clouds
beginning to clear in western IL late Thur night. Despite some
partial sunshine on Friday with a brief period of high pressure,
high temps will be cooler than Thursday as colder air is wrapped
into Illinois on NE winds. Highs will top out in the low 50s
north of Peoria, and low 60s south of I-70.

The break in the rain chances will be short-lived, as the next
wave of sfc low pressure approaches Friday night and passes
across NW Illinois on Saturday. That will bring rain chances after
midnight Friday night, with likely rain from Lincoln and north
Saturday morning. Rain chances will continue north of I-72
Saturday afternoon, with rain becoming likely west of I-57
Saturday night.

A more significant system is on tap for Sunday afternoon and
evening, as a parent low pressure center travels from the central
Plains into NW Ontario during the day. That low will drag a cold
front across central Illinois for late Sunday afternoon and
evening. Instability parameters show MUCAPES of 1500-2000 J/KG
ahead of the front, along with bulk shear values around 60kts.
There is some potential of severe wind and hail, if these
parameters continue to show up in the extended guidance.

High pressure will build briefly into Illinois late Sunday night
into Monday morning, but yet another low pressure system will
approach Illinois from the southwest Monday afternoon. Rain
chances will expand from south to north, especially east of I-55
Monday afternoon. Likely rain chances are expected south of I-70
Monday evening, with diminishing chances into Tuesday morning as
the weak low departs to the east.

Model differences show up for the later extended periods, with
potential for another low pressure center pushing across Illinois
for Tuesday afternoon into Tuesday night. No significant storms
are expected with that wave, but enough cold air could dive into
Illinois behind the low for a few flakes of snow north of I-72
late Tuesday night, as lows dip into the low to mid 30s in that
area. Light rain could linger on Wednesday, as high temps struggle
to reach the mid to upper 40s.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1151 PM CDT Wed Nov 1 2017

IFR and LIFR conditions will continue at all TAF sites overnight
and into the morning hours. Some MVFR conditions are trying to
sneak into western IL from eastern MO, but models show this not
getting to SPI until sometime around noon and then spreading east
to DEC. PIA/BMI/CMI may see lower MVFR conditions, but believe as
front pushes through the area, IFR/LIFR conditions will return til
the front moves through tomorrow evening through after midnight
tomorrow night...from northwest to southeast. PIA will see
improving conditions first, followed by BMI and SPI, then DEC and
CMI after end of TAF time. Winds will be southerly overnight but
then become light and variable around PIA as the front approaches
and then at the other sites as the front moves through, then
becoming northerly behind the front...in the evening hours or
later.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

UPDATE...Auten
SHORT TERM...Shimon
LONG TERM...Shimon
AVIATION...Auten

Hazardous Weather Outlook
National Weather Service Lincoln IL
316 PM CDT Wed Nov 1 2017

ILZ027>031-036>038-040>042-047>050-021100-
Cass-Fulton-Knox-Logan-Marshall-Mason-McLean-Menard-Morgan-Peoria-
Schuyler-Scott-Stark-Tazewell-Woodford-
316 PM CDT Wed Nov 1 2017

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

.DAY ONE...TONIGHT...

No hazardous weather is expected at this time.

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

Severe thunderstorms, potentially containing large hail and
damaging wind gusts, are possible Sunday or Sunday night. It is
to early to determine specific timing or locations at this point.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed through tonight.

ILZ043>046-051>057-061>063-066>068-071>073-021100-
Champaign-Christian-Clark-Clay-Coles-Crawford-Cumberland-De Witt-
Douglas-Edgar-Effingham-Jasper-Lawrence-Macon-Moultrie-Piatt-
Richland-Sangamon-Shelby-Vermilion-
316 PM CDT Wed Nov 1 2017

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

.DAY ONE...TONIGHT...

No hazardous weather is expected at this time.

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

Isolated thunderstorms are possible Thursday afternoon into
Thursday night. Thunderstorms may produce locally heavy rain and
dangerous lightning. Additional thunderstorms are possible
Saturday.

Severe thunderstorms, potentially containing large hail and
damaging wind gusts, are possible Sunday or Sunday night. It is to
early to determine specific timing or locations at this point.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed through tonight.

HJS