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Area forecast discussion
National Weather Service Lincoln Illinois
743 PM CST Mon Nov 11 2019

Synopsis...
issued at 743 PM CST Mon Nov 11 2019

Following the snow that fell on Veterans Day, unseasonably cold
air will prevail over central Illinois into Tuesday. Near record
temperatures are expected for overnight lows, as well as the highs
on Tuesday, which will only reach the lower 20s despite abundant
sunshine. Wind chills below zero are on tap for late tonight and
early Tuesday. A slow rise in high temperatures is expected the
balance of the week, though remaining well below mid November
normals.

&&

Update...
issued at 743 PM CST Mon Nov 11 2019

Back edge of the snow has reached Olney and Lawrenceville, and
should move out of those areas shortly. Clearing line is following
quickly behind, with satellite imagery from 7:30 PM showing it
from about Rantoul to Taylorville, and remaining areas north of
I-70 should clear out over the next couple hours. Temperatures
back in the mostly clear areas are already down into the upper
teens, and dew points in the single digits near Peoria and
Galesburg show the potential lows. This particular area had the
least amount of snow, so hopefully that will keep the sub-zero
temperatures at Bay. However, record lows are likely in much of
central Illinois (see climate section below), and wind chills
are still on track to reach the single digits below zero, perhaps
around 10 below in some areas near I-74.

Remainder of the Winter Weather Advisory should be able to be
dropped by the top of the hour. Zones/grids were updated earlier,
but will be refreshed once the advisory is gone.

&&

Short term...(this evening through tuesday)
issued at 250 PM CST Mon Nov 11 2019

The initial concerns will focus on timing of snowfall ending, as
well as total snowfall amounts through early evening. Recent
snowfall reports have come up to original forecast amounts, and a
widespread swath of 2-3 inches looks likely in most of the
advisory area, with 4" totals possible where frontogenetic bands
reside the longest in east-central portions of the County Warning Area the rest
of this afternoon. NAM-nest and nam3km updates today have pointed
toward a band of 3-4" snows roughly from Taylorville to southern
Vermilion County. The current radar trends are providing some
support for that scenario, with stronger radar returns setting up
in bands across that area and to the southeast.

Based on timing of snow ending, have allowed our northern tier of
counties north of Canton to Bloomington to expire at 2 PM. Areas
south of Rushville to Clinton to Taylorville portion of the
advisory was extended a couple hours to 4 PM, based on rough
estimations off radar. The southeast-east counties have the
advisory through 9 PM, and that looks fine. We will clear counties
as conditions warrant.

Gusty north-northwest winds will continue for the balance of the night, with
some minor drifting likely in open areas that received 2-3"
snowfall. That could create renewed slippery conditions even in
areas that have treated roads. Hazardous travel will likely
extend overnight as a result.

Winds gusts late tonight will likely push wind chill readings
below zero in our entire forecast area, as low temps settle out
around 5 above zero toward Galesburg and in the mid teens toward
Lawrenceville. Single digit low temps are likely north of a line
from Jacksonville to Danville.

Tuesday will see mostly sunny skies, but the Arctic air mass
settling south with the 1045mb high pressure center will cause high
temps to struggle to climb into the lower 20s. Northwest winds will
finally subside more noticeably Tuesday afternoon, as they begin
to shift to the west and SW.

Long term...(tuesday night through monday)
issued at 250 PM CST Mon Nov 11 2019

The wind shift to the SW Tuesday night along with increasing
clouds will help to keep low temps from dropping as cold as
Monday night, in most of the area except for our far eastern
counties, where light and variable winds will linger later Tuesday
night. Lows will still be quite cold, in the 10-13f range across
the board.

A weak shortwave and cold front will approach central Illinois on
Wednesday, creating a thickening and lowering cloud cover. Slight
chances of light snow will develop ahead of the front late Wed
afternoon and evening, mainly north of a line from Elmwood to El
Paso. Little to no snow accumulation is expected with that system,
as the better forcing for precipitation will reside farther north
in Wisconsin and Michigan.

Thursday and Friday, the upper air pattern will be in a northwest flow
regime toward central Illinois. This typically means periodic
precipitation events. However, all the weather producing
shortwaves look to remain north of our area during that time. Dry
conditions are actually expected through Saturday evening, as
upper level ridging advances from the Central Plains into
Illinois Friday night and Saturday.

A long wave trough will become established in the northern plains
on Saturday, advancing into Illinois Sunday and Sunday night.
That will bring chances for scattered rain/snow showers to the County Warning Area
starting Sunday afternoon, but better chances will come Monday
night. One benefit of the trough developing in the plains will be
southwest surface winds bringing warmer temps next weekend.

&&

Aviation...(for the 00z tafs through 00z Tuesday evening)
issued at 527 PM CST Mon Nov 11 2019

Snow has moved out of kcmi recently and visibility there has
quickly shot up. Back edge of MVFR cloud deck was along the
Illinois River and moving southeast, and about to exit kpia. Will
include a tempo period at kbmi/kspi as passage there should be
within the first half hour of the forecast period, and should
clear kcmi before 03z. Winds remain gusty, and although the gusts
should settle a bit as we approach mid to late evening, expect
sustained northwest winds around 15 knots to continue into midday.



&&

Climate...
issued at 743 PM CST Mon Nov 11 2019

Record temperatures for tuesday:

Location record low record cold high
-------- ---------- ----------------
Bloomington 10 (1911) 26 (1995)
Champaign 9 (1911) 27 (1920)
Charleston 11 (2017) 28 (1920)
Decatur 10 (1976) 29 (1920)
Galesburg 8 (1986) 24 (1940)
Lincoln 10 (1919) 29 (1920)
Olney 15 (1976) 32 (1920)
Peoria 9 (1986) 18 (1911)
Springfield 12 (1986,95) 19 (1911)

Normal lows are in the mid 30s across central Illinois, and in the
upper 30s south of I-70. Normal highs are in the mid to upper 50s,
warmest south of I-70.



&&

Ilx watches/warnings/advisories...
Winter Weather Advisory until 9 PM CST this evening for ilz056-
057-062-063-066>068-071>073.

&&

$$

Update...geelhart

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