National Weather Service Releases Information On Today Snow Forecast

Update from the National Weather Service at 5:51 am this morning:

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
551 AM CST Sun Dec 4 2016

324 AM CST

Through tonight...

Main forecast concerns/challenges are with the expected
accumulating snow over much of northern Illinois and northwest
Indiana this morning into the late afternoon. Main forecast
changes this morning were to increase snowfall amounts and expand
the advisory southeast to now include Livingston/Kankakee counties
in Illinois and Lake/Porter counties in northwest Indiana.

Everything still appears to be on track for the first
accumulating snowfall today. Upper level trough noted on satellite
imagery, with several embedded impulses quickly lifting northeast
into the mid Mississippi Valley. Ahead of this feature, isentropic
ascent is also helping to saturate the column. Although returns
noted on radar, this saturation has not occurred quite yet, with
snow not occurring at this time. Adjusted pops in the near term to
reflect latest trends with upper level support providing the onset
of snow across the far western CWA right around 12Z. This would
include all areas in the west, along the I-39 corridor. Remaining
areas to the east in northern Illinois still on track for right
around a 15z time frame, and then soon there after for areas in
northwest Indiana. Given this noted time line, have adjusted
timing of the advisory, mainly to delay the eastern half until

As this upper level trough swings through the area later this
morning into the afternoon, expect a transition from light snow to
more moderate intensity snow as large scale ascent really ramps up
ahead of this feature. Most guidance in agreement with the
increase in forcing due to many features coming together, which
include a stout negatively tilted trough and more potential for
instability aloft. Would anticipate many locations across much of
northern Illinois and northwest Indiana to see this ramp up in
snow intensity by midday, and even more so by early to mid
afternoon. This not only includes areas along the I-39 corridor
which was previously noted, but now also includes many areas in
the northern two thirds of the CWA likely centered from just north
of I-88 south to along/south of I-80. In these locations, strong
forcing and more efficient snow production will likely allow for
an increase in snow amounts even into the afternoon when the more
intense snow will be able to offset melting. In the height of the
more intense snow, 18-23Z, am a little concerned that the snow
will come down hard enough to accumulate more on the roadways with
at least slushy conditions possible. All of this and the increase
in snow amounts, feel the advisory is still warranted and worthy
of expansion. Now have snow amounts of 3-5 inches along the I-39
corridor, 2-4 inches elsewhere in the advisory in northern
Illinois and northwest Indiana, and then 1-3 inches across the far
southeast CWA. In this location, rain may briefly mix with snow
but do think forcing will be strong enough even in this location
to help the column/boundary layer to cool to support all snow in
the afternoon. Snow will quickly taper off right around the 00z
time and although some light snow may still be ongoing across the
eastern CWA in the 00-03z period, it will likely be light enough
to not warrant extension of the advisory.



347 AM CST

Monday through Saturday...

Monday appearing dry/quiet on the backside of this system with
rising heights and building high pressure. Continued WAA will
usher in a warmer airmass but wonder what impact this will have on
high temps with cloud cover possibly lingering and with a snow
pack likely in place. Still keeping an eye on two possible systems
to affect the area during the week. Confidence is still on the
lower side with the first system arriving Monday night into
Tuesday. Timing and placement adding to the low confidence as well
as extent of the airmass which would be in place. Have continued
to limit pops as well as continued to mention both snow and rain.
Much colder airmass still expected later in the week, however,
confidence also remains low with snow potential Wednesday night
into Thursday. Still remains a possibility for snow but with
varying guidance, no change in confidence. Much colder air and
lake effect snow potential will then be concerns through the
remainder of the work week, as well as snow potential returning
CWA wide by the weekend.

Winter weather advisory has been issued for our area



It is official. Our first winter advisory of the season has now officially been issued.  Please use caution when driving! 


Winter Weather Advisory in effect from 7 am to 6 PM CST

The National Weather Service in Chicago has issued a Winter
Weather Advisory for snow which is in effect from 7 am to 6 PM
CST Sunday.

* Timing... light to moderate snow will begin Sunday morning and
  continue through Sunday afternoon.

* Snow accumulations... 2 to 4 inches with the heaviest amounts
  generally northwest of a Chicago to Peru line.

* Main impact... slippery conditions are expected on untreated
  surfaces... creating hazardous travel.

* Other impacts... visibility may fall to around one half mile at
  times... causing an additional travel hazard.

* Note... impacts may be mitigated by mild Road temperatures on
  heavily traveled roads... such as in the city of Chicago and
  immediate suburbs.

Precautionary/preparedness actions... 

A Winter Weather Advisory for snow means that periods of snow
will cause primarily travel difficulties. Be prepared for snow
covered roads and limited visibility... and use caution while






marvin tire


NWS Releases Information On The Latest Snowfall



Question: Has Rockford never received any snowfall during a winter in the past? What was the latest snowfall on record for Rockford?

From the NWS: Neither Chicago nor Rockford have seen measurable snowfall yet this cool season. Historically speaking, Chicago had seen measurable snowfall by this date 82% of the time and Rockford 75% of the time. There is slight chance this streak could be broken this week, but if not this year will go down as one of the latest first measurable snowfall years in both Chicago and Rockford!

Mark Henderson: There’s never been a winter without snow. Latest first measurable snow here was winter of 1939-40. First measurable snow that winter happened on January 7

Adam Tubbesing: The winter of 1906-1907 had a total amount of 2.8″. But rockford has never had a complete snow free winter since records were kept.