January 8-10, 2024 | Winter Storm Potential

[Organicforecasting]

4 hours ago, CIWeather said:

Our storm is named Finn 😂

My nickname in college was Baby Faced Finster

[Hiramite]

1-6-24 0z LPT:

A quickie, my Obs:

Ukie pretty much held its ground, the other 3 ticked NW a bit.

Pressures continue to rise ever so slightly.

I might do one more tomorrow AM along with the first one for the 11-13 storm.  I don’t work during NFL football.

 

This morning's 0z run below.

Quote

 

Edited January 6 by Hiramite

[Ingyball]

These northward trends have been great for me. I feel like if the 0z runs tonight don't windshield wipe in the other direction I might come out of this with only a minor event or just rain. 

[snowlover2]

[Icewoz]

DTX isn’t impressed with any of the three systems coming up. Only thing it will bring is colder air next weekend. They haven’t even bothered with a hazardous weather outlook.

https://www.weather.gov/dtx/ExpertForecastOpinionAFD

 

[SOMOSnow]

Springfield NWS stated that full sampling is tonight. Major shift back South on the way! Let's go!!!!!!!

Edited January 7 by SOMOSnow

[snowlover2]

[snowlover2]

[snowlover2]

[SnowloverSid]

On 1/5/2024 at 10:35 PM, CIWeather said:

My God, over half the state of Illinois would be shut down!  

This would even outdo the three feet that I received in upstate New York three years and three weeks ago. It is about as likely as 80 degrees this month above the 40th parallel.

[SnowloverSid]

It looks like mostly cold rain for us folks in St. Louis, with possibly some backend flakes by midweek.

[Organicforecasting]

https://collaboration.cmc.ec.gc.ca/cmc/cmdn/pcpn_type/pcpn_type_gem_reg.html

[Organicforecasting]

DVN with a great AFD

 

Area Forecast Discussion
National Weather Service Quad Cities IA IL
246 AM CST Sun Jan 7 2024

.KEY MESSAGES...

- Strong Winter Storm to affect the region Monday night into
  Wednesday morning. Prolonged period of snowfall with two to
  three periods of more intense snowfall and increasing winds
  Tuesday evening into Wednesday.

- Impacts from the storm could linger into the morning commute
  on Wednesday as well.

- Additional chances for snow exist later in the week as the
  arctic cold air moves into the area.


&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 152 AM CST Sun Jan 7 2024

Upper level ridging will continue to build into the area this
morning. This means the light snow will eventually end from west
to east with only minor snowfall accumulations. This ridging is
short lived as the flow turns SW ahead of the strong storm
system moving into the area for early this week. While upper
level ridging and sinking motion is expected, do not expect the
clouds to break up today. Think that we will see stratus the
whole day. As such, have lowered temps a couple of degrees
today. Overall though, a quiet next 24 hours is expected across
the area.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 152 AM CST Sun Jan 7 2024

All attention is on the strong winter storm affecting the area
Monday evening into Wednesday morning. A prolonged period of
accumulating snow is expected for the area. Later on Tuesday and
into Wednesday, winds will increase and lead to blowing and
drifting after the snow ends into Wednesday AM. Due to the
increase in confidence and the expected impacts from this storm,
a winter storm watch has been issued for the entire area.
Instead of getting specific with areas and times of heavier
snowfall, opted to go with area- wide watch with idea that later
shifts would have better clarity on when to edit start times/
end times to better suit different portions of the CWA.
Regardless, this storm will be rather impactful for the area and
we could see a impacts stretching into Wednesday, well after
the snow ends.

Let`s talk about storm track of this system. While there had
been some waffling of the guidance the past few days, the main
track was always along and east of the Mississippi River. When
the NAM came in yesterday, it was much further NW than any of
the guidance. The NAM appears to have the system already
vertically stacked, while the other guidance were more
progressive. I discount the NAM at this time. However, the GFS,
ECM, EPS and GEFS have all shifted to the NW. This apparently
has been seen with other systems this winter as well. As such,
have bought into the shift with the heavier axis just west of
the river now. This could continue and parts of the eastern and
southern watch may become advisories instead of warnings later.
This can be fine tuned especially when we decide to go with
warnings etc.

There are two definite windows of heavy snow and a potential
third one that could be between the two. The first is with the
warm advection snow Monday evening. Deep DGZs could yield large
dendrites and even some aggregates that could quickly accumulate
between 03z and 06z across most of MO and Iowa. This will wane
before another wave of intense snow moves up just before
daybreak. The CAMs depict convective snow moving into our area
between 09z and 12z. This heavy snow is less certain but could
really add up quick if the CAMs are correct. Then the system
pivots across our area and we see the wraparound/trowal into our
area as well. Deep DGZ again will produce bountiful dendrites.
However, at this time winds may be high enough to shatter the
dendrites meaning accumulation rates may be lower than we would
see in similar setups. The heaviest snow looks to fall over us
where some portions of the area will see the WAA snow and then
pivot into the wraparound snow. That area could easily see 8 to
12 inches of snow through the event. This area is the area we
still need to nail down and will in later shifts.

As far as snow composition, believe the snow will start out
rather wet and heavy with SLRs of 7-10:1 before we turn to our
more climatological norm of 12:1 later on Tuesday afternoon.
Eventually even drier snow is expected, especially as the winds
ramp up after 00z Wednesday. We could see this snow blowing and
drifting into the AM Wednesday. Wind gusts to 40 MPH are
possible. The NBM is even higher with winds, but tamped those
down at this time. Regardless, its going to be an issue after
the snow ends that evening and morning

[Organicforecasting]

LSX

Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
416 AM CST Sun Jan 7 2024

.KEY MESSAGES...

- A winter storm will impact the region late Monday through
  Tuesday, though its track has shifted slightly further
  northwest. Therefore, the axis of heavier snow has also shifted
  further northwest, with the greatest impacts now expected
  primarily over northeastern Missouri and west-central Illinois.

- A Winter Storm Watch is now in effect for portions of
  northeastern Missouri and west-central Illinois from 6pm Monday
  through 12am Wednesday.

- Active weather will continue into next weekend, with another weather
  system potentially impacting portions of the Midwest Friday
  and/or Saturday.


&&

.SHORT TERM... (Through Monday Afternoon)
Issued at 413 AM CST Sun Jan 7 2024

Current water vapor imagery shows a shortwave digging into the Mid
South within a low amplitude upper-level trough. Forcing from these
features and an upper-level jet streak is shifting eastward, with
the trailing edge of an area of patchy flurries and drizzle
associated with these forcing mechanisms aligned along the
Mississippi River. These flurries and drizzle will continue to move
eastward through the early morning hours exiting the CWA around
sunrise.

Through today, an upper-level ridge will build into the Midwest as
high pressure takes over at the surface. This will lead to a
gradually thinning cloud deck and some peaks of sun this afternoon as
our weather stays calm and temperatures seasonable.

As the ridge amplifies overnight and the surface high moves
eastward, low-level flow will become southerly over the region
tonight into tomorrow, providing a slight bump in temperatures and
an increase in moisture ahead of a trough digging equatorward across
the western CONUS and our anticipated low pressure system deepening
across the Southern Plains.

Elmore

&&

.LONG TERM... (Monday Evening through Saturday)
Issued at 413 AM CST Sun Jan 7 2024

Through the latter part of Monday, the aforementioned trough will
eject out into the Plains with its corresponding surface low making
its way east-northeastward toward the CWA. Upper-level lift via the
approaching trough and a jet streak will continue to strengthen the
low and combine with a strong low-level jet to feed a large shield
of precipitation associated with the warm air advection wing of the
approaching low. This shield will move into portions of central
Missouri early Monday evening. I can`t rule out rain before that,
but dry low levels per deterministic soundings are expected to
inhibit rainfall until the low levels can sufficiently saturate. As
they do, temperatures will cool to the wetbulb, which will be right
around freezing for portions of northeastern Missouri and west-
central Illinois. A saturated dendritic growth zone will allow for
ice growth aloft and snowfall for areas where surface temperatures
can sufficiently cool to or just above freezing.

As the low moves further into the area Monday night and Tuesday
morning, a rain/snow mix is expected generally along and north of I-
70, with more and more snow mixing in further north in northeastern
Missouri and west-central Illinois. Into Tuesday during the day, the
deformation zone of the low will swing through the area, changing
precipitation over to primarily snow as temperatures drop. Snow is
expected to then exit the CWA to the east Tuesday night.

While that is generally the expected progression of the system, both
deterministic and ensemble guidance still show varying low tracks.
Even short-range hi-res guidance that has come into view of the
system shows varying paths of the low. The consensus has been for a
slight northward shift in the path and greater snow totals, but
given guidance spread, I still can`t rule out slight shifts in the
spatial foot print of heavier snow. Right now, the probability for
5" or more is 75% or higher and mainly coincides with the Winter
Storm Watch. Where the pivot point of the warm air advection wing
and deformation zone of the low sets up, up to 12" of snow is
possible (roughly 25% chance). This currently looks to be over north-
central and northeastern Missouri. Additionally, the snow
accumulation with the deformation band across much of the area is
about an inch. However, I can`t rule out mesoscale banding within
the main deformation band exceeding that forecast for portions of
the area. Such details will likely be clearer within the next 24
hours.

Also of note with this system is winds. As the deformation zone
swings through the CWA, winds will pick up out of the west-northwest
and gust 30-40 mph. This could cause issues due to snow accumulation
on tree limbs, especially for areas that see heavier snowfall.

Winds die down on Wednesday as the pressure gradient slackens thanks
to the departing surface low. Upper-level ridging quickly builds
into the Midwest in the wake of the departing trough, leading to
calm conditions on Wednesday. However, these calm conditions will be
short-lived. A shortwave quickly passes through the Midwest on
Thursday - its exact track uncertain at this time. It will not have
much moisture to work with, but guidance consensus is that there
will be enough for light precipitation mainly north of the CWA per
ensemble probabilities. Regardless of the shortwave`s track, it will
swing a cold front through the CWA, setting the stage for at the
very least well below normal temperatures for the weekend. We
continue to watch for the potential of another low pressure system
to interact with this cold air and impact the CWA with wintry
precipitation. However, ensemble guidance still shows wildly varying
solutions, with the low track ranging from through the Middle
Mississippi Valley to the Southeast. We should likely have a better
idea of the potential of this system and be able to delve into its
details once Tuesday`s event has passed.

Elmore

[Hiramite]

1-6-24 0z Low Party Tracker (pardon the color snafu)

My Obs:

Canadian finally starting to join the party and moving west.  Still a bit of spread.  (Keep in mind locating the low center in some instances is open to interpretation.)

Pressures seem to have stabilized.  Pretty much a ~low 980’s storm around Chicago.  Euro still the strongest.

This is probably the last one for this storm unless there is a demand for the 12z to be published between the 1:00 and 4:00 games. Let me know.

Good luck MW folks!!!!

 

Yesterday's 12Z below.

Quote

 

Edited January 7 by Hiramite

[Organicforecasting]

[Central Illinois]

this is starting to look like a slop fest more than anything 

[StormfanaticInd]

[StormfanaticInd]

Front end thumps can be fun until it all gets washed away hours later 🙄

[Central Illinois]

2 minutes ago, StormfanaticInd said:

Front end thumps can be fun until it all gets washed away hours later 🙄

lol all the snow here this winter has been like that. It snows during the night and its all gone/washed away by mid afternoon

[MidMichiganWx]

Really riding the hardcore rain/snow line IMBY. 

I suspect a few quick inches of heavy snow followed by a changeover to all rain. Best case scenario is the low tracks slightly further southeast but I just have a feeling this will be an overall bust for me. Super common for Mid-MI area for some reason - always skirting that freezing line on these storms. 

We'll see. 

[SnowloverSid]

NWS has lowered Wednesday’s predicted max from 45 back down to 40. I hope this means a better chance of some snow at the beginning or end so not all of the weekend snow goes down the drain.

[Cary67]

Will resuscitate this thread briefly. Should receive a front end thump later this evening of 1-2". Best areas remain further south for heavier accums. Main event deformation band will swing through Tue morning-afternoon. Hi res models indicate even far NW burbs of Chicago could be dry slotted and go to drizzle or rain before late switch to snow. Big winners should be Dubuque to Madison WI line. Hope for 3-4" total. Under WWA tonight and WSW for tomorrow. WSW probably issued in case a wobble SE brings heavier snow band back in play.

[Hiramite]

A highly impactful storm in many aspects!!

[Ohiobuckeye45]