Chris's Corner - Ground Hog's Day Storm 2.0 - Winter Reboot?

My snowblower didnt wanna start. I was able to get a new carburetor today and will fix it tomorrow. I learned my lesson... Shovels are handy, salt is ready and birds here are fed.

The amount of spread even at this distance is crazy. From nothing to near 2 feet!

Is this still off shore?

Ok. I PROMISE to bookmark it this time. Someone posted an exceptionally helpful site that allowed one to track in real time the 540 line. What is that link? Please. And I’m sorry.

Just sit in on the NWS Conf Call, nothing earth shattering to report other than steady as she goes, and the forecast totals WILL change will plenty of time to still sort out the details.

Snow/Sleet in the metro is 5-10, they showed a best case scenario of around 4", and worst case scenario around 10". Further north in the band from Sedalia to Pittsfield 11-17", with a best case around 9" and a worst case around 19". 

KFAM area, 2-5", with a best case around 1" and a worst case around 6"


I assume the graphics including timing and totals would be up shortly if not already.

Going off the NAM... there are some pretty ugly lapse rates Wednesday morning int the 500-600 layer.... from 6.3 to 8.1c That's where the CAPE is noted...so there is a good chance at thunderstorms feeding into the thermal boundary and convectively enhanced precip.

Those lapse rates drop lower in the atmosphere during afternoon and range from 6.2 to 8.6c.

Thursday's lapse rates are not impressive. Nor is the CAPE. Thursday looks to be a lot of large scale UVM associated with the right entrance region.

National Weather Service Saint Louis MO
313 PM CST Mon Jan 31 2022

.SHORT TERM... (Through Late Thursday Afternoon) Issued at 307 PM
CST Mon Jan 31 2022

...A Major Winter Storm is expected late Tuesday into Thursday...

Attention was given almost exclusively to the mid-week winter
storm. The forecast remains on track for the major winter storm
that will impact the forecast area starting Tuesday night and
continuing through Thursday.

Key Messages:

1. Event Occurrence: Confidence remains high that a significant
winter storm moving through the forecast area beginning Tuesday
night and lasting into Thursday.

2. Impacts: Significant accumulations greater than 6" of wet, heavy
snow is expected across a large portion of the forecast area,
falling mainly between Wednesday and Thursday. A corridor of greater
than 12" of snow and significantly less wintry mix is possible along
and north of the I-70 corridor where forcing will be greatest. Ice
accretion in excess of 0.10" is expected across southeastern
Missouri and southern Illinois, and combined with breezy conditions
during and after the event could result in power outages.

3. P-Type: Uncertainty remains in the exact transition of rain to
wintry mix to snow and the timing of these transitions. There is a
chance that some areas around the I-44 corridor and associated areas
eastward could see significantly more sleet than snow.

4. Longevity/Timing: The system is still expected to exit the region
during the day Thursday, though light snow could linger in its wake,
particularly east of the Mississippi River.

5. What`s Changed: Guidance has come into better agreement on the
track and movement of the low, and is consistently placing the
corridor of heaviest snowfall along and north of the I-70 corridor.

6. Remaining Uncertainty: As in previous forecasts, the depth and
speed of the cold air aloft into the region remains uncertain and
will have significant impacts on how much ice, sleet, and snow
accumulations over much of the forecast area.

Forecast details:

The northern stream axis of a split stream trough will move
across the US-Canada border during the day Tuesday with a surface
low sliding from the Great Lakes region into New England. The low
will drag a robust cold front southward into the forecast area
Tuesday afternoon. Rain will bloom ahead of and along the front,
aided by warm air advection along southerly flow, as it moves
through the moist and seasonally warm air across the region.
Temperatures will be seasonally warm ahead of the front thanks to
the increased warm air advection.

By Tuesday night the entire split stream trough will be moving
through the western half of the CONUS, keeping the region within
southwesterly flow aloft and positioning the area between the
upper- level jet couplet. At the surface the cold front will be
stalled just south of our forecast area. We will have no shortage
of lift for precipitation with mid-level disturbances traveling
northeast across the region, interaction with the ULJ dynamics,
and isentropic lift and warm air advection overrunning the front.
Overnight Tuesday into Wednesday cold air will continue surging
into the region behind the cold front and beginning to erode the
elevated warm nose. Confidence is high this transition will occur
quickly Tuesday evening across northeast Missouri and portions of
far west-central Illinois closest to the Iowa-Missouri border.
Confidence decreases across areas further south where guidance
sources continue to diverge in how rapidly the profile will cool.
As it stands a period of wintry mix, including sleet and freezing
rain, is expected overnight across central and east-central
Missouri and portions of west-central Illinois before
transitioning to mostly snow.

Precipitation will fall across the bi-state region through the day
Wednesday, though we could see a brief break in precipitation or at
least lighter QPF Wednesday afternoon and evening at the entrance
region of the ULJ moves northeast of the forecast area and
isentropic lift decreases. Precipitation type during this period
continues to be uncertain due to thermal profile so I can`t rule out
sleet and freezing rain mixing into the snow along and south of I-70
during the morning Wednesday. Southeastern Missouri and southern
Illinois will be last to cool and so last to make the transition
from liquid rain to frozen precipitation Wednesday afternoon. The
elevated baroclinic zone is then expected to stall through this
region, and combined with chilly surface temperatures, is expected
to produce ice accumulations over a 1/4" across the far
southeastern CWA. These values could still change as guidance gets
a handle on the thermal profile. There is a reasonable chance
that if elevated temperatures do not cool enough in the
transitional area along and around the I-70/I-44 corridor that
much of the current forecast snow falls as sleet.

By Wednesday night the southern stream of the mid-level split stream
moves into the region. A low will move northeast through the lower-
Mississippi Valley during this period in concert with the approach
of the mid-level trough. Forcing from the low will provide robust
lift for precipitation across the forecast area, and given the
classic Midwest heavy snowfall model, a narrow corridor of heavy
snowfall is expected on Thursday. The current track of the low
places the heaviest snowfall through areas along and north of I-70
in Missouri and Illinois. Precipitation is expected to be
predominately snow from Wednesday night through the end of the storm
given the more robust push of cold air into the region on the
northwest side of the low. By Thursday afternoon the low will track
east-northeastward out of the region in concert with the
northeastward lifting trough, aided by a robust high moving into the
area. Winds will be breezy overnight Wednesday into Thursday, and
while blowing snow is no longer considered a threat, power outages
associated with these winds and significant ice accretion on the
powerlines is possible.

This a long duration winter event with heavy, wet snow forecast to
fall across the area for 36-48 hours. Settling of the snowpack
should be expected over the event, which will impact storm total
snow amounts and could create a discrepancy between the current
forecast and final totals.

18Z ICON looks pretty good. 2.5" QPF through the metro area with 8-12" of modeled positive snow depth change from southeast to northwest through the metro area. There really isn't anything that is inconsistent with the current forecast. It's yet another piece of evidence supporting a significant weather event for the metro and surrounding areas.

BTW...I'm okay with the Rams winning yesterday. At least this way the entire world will get the chance to watch them lose the biggest game of the year.

18z GFS is going to be a great run probably a touch colder metro goes over to snow between 8-11am

Ya GFS is coming in just a tick colder

Been a pretty consistent trend today

Like Jmg mentioned, wonder if some real world data of the cold air coming is influencing that

It has the metro sitting 16”-20” on Kuchera, wow
Edit - 24” area in the metro

MODOT is really going to be challenged given this starts as rain - They will not be able to pre-treat and will already be behind once the ice / snow hits