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

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

Key Messages:
1. Event Occurrence: Confidence is high that a major
winter storm will move through the forecast area Tuesday night into
Thursday, producing widespread snow accumulations and more limited
accumulations of sleet and ice.

2. Impacts: Significant snowfall accumulations above six inches are
expected in the forecast area but the exact location of the highest
amounts continues to shift, and is still uncertain. Breezy
conditions Thursday will make blowing and drifting snow a concern.

3. P-Type: Confidence is low in the timing of precipitation type
transition from wintry mix to snow across most of the forecast area.
There is concern that the current forecast transitions mixed
precipitation to snow too quickly, which would impact snow totals.

4. Longevity/Timing: Confidence is medium that wintry precipitation,
including snow, will begin falling Tuesday night into Wednesday
morning. Precipitation exit on Thursday remains uncertain given the
track and speed of the low.

5. Remaining Uncertainty: The uncertainty in this system can be
summed up into two features: the depth and southward expansion of
the sub-freezing air Tuesday night into Wednesday, and the location
and speed of the low Wednesday into Thursday. Both of these will
determine how much snow, sleet, and ice falls and where.

Forecast:
Southwesterly flow will become established throughout the
atmosphere on Tuesday as a split flow mid-level trough moves
through the western CONUS and into the region. Moisture return and
warm air advection along this flow, particularly in the lower
levels, will make for a warm day on Tuesday ahead of the
significant winter storm moving into the region Tuesday night.
Details have changed little in the overall synoptic pattern:

The axis of the northern stream trough will swing across the central
US-Canada border Tuesday while at the surface a low pressure will
slide into southeastern Canada. The low will drag a strong cold
front through the mid-Mississippi Valley Tuesday afternoon. Moisture
ahead of the front coupled with robust frontogenesis and warm air
advection will produce widespread rain ahead of and along the front.
The front will stall Tuesday night just to the south of the CWA
border, across central Arkansas into the Missouri Bootheel and Ohio
River Valley. Isentropic lift and continued warm air advection
overrunning the stalled front will renew, or in some areas, continue
precipitation across the CWA overnight into Wednesday.

As temperatures below freezing behind the front Tuesday evening,
rain will begin to change over to wintry precipitation. A mix of
wintry precipitation, including sleet and freezing rain, is expected
before the 925-850mb layer cools sufficiently to make the changeover
to snow. Areas across the northern CWA are expected to have a very
short window of wintry mix, changing over from rain to snow quite
rapidly. Areas further south are more uncertain, but overall more
likely to see a period of wintry mix before changing over to snow.
There is some uncertainty in how long this period of wintry mix will
last, while warmer guidance has exhibited a cooling trend to erode
the warm nose quicker, guidance is still split on how quickly the
warm nose is eroded. The newest guidance has continued to cool
surface temperatures Wednesday, and as it stands the high
temperature on Wednesday is likely to happen at midnight with
continual cooling through the day. Cold air advection along the
northeasterly post-frontal flow will eventually succeed in changing
precipitation over to snow on Wednesday.

By Wednesday evening the mid-level trough will advance into the mid-
Mississippi Valley while an 850 mb low pushes northeast across the
lower Mississippi Valley, a classic Midwest heavy snow scenario. The
combination of the cyclonic forcing and upper level jet couplet will
provide more robust lift for precipitation. The location of the axis
of heaviest snowfall is still uncertain, as the track of the 850 mb
and surface low have shifted southeast somewhat in recent model
runs. The WPC cluster analysis has been indicating a trend among
synoptic guidance to pull the low and associated QPF on Thursday
southeastward, which would stunt snowfall across the northern CWA.
The final location of the 850 mb low track will impact the final
location of the axis of heaviest precipitation.

Regardless of where the low is positioned, it will move northeast
along the stationary front out of the region Thursday in concert
with the northeastward lifting mid-level trough, ending widespread
snowfall. The exact speed and timing of the exit of the low is still
uncertain, but is expected sometime Thursday.

A robust surface high will push into the region on Thursday, helping
clear to push precipitation out of the region. Conditions on
Thursday as this high moves into the area will become breezy as the
pressure gradient tightens, increasing the risk for blowing and
drifting snow. Cold temperatures will linger for a couple of days
after this system exits the region.

Snowstorm just beat ya Snowman w/ the NWS post haha.

TWC has us in the 12”-18” band with southern counties in there as well



imgur.com/a/NbJKyo5”

It's hard to get too excited when Frivs isn't on board.

I said this yesterday or Friday how often does the NAM start out in its long range as the coldest only to trend as the warmest then as we get closer it settles back down. It’s the NAM at 60-84 hours , it wouldn’t shock me a bit if it’s one of the coldest by tomorrow morning.

18z RGEM still looks awesome about the same temp profile it’s had the whole time . Nice transition from rain to sleet to snow early Wednesday morning

I’m still excited steady as she goes

Also 18z icon continues to be a beast, it’s been very consistent which sometimes it bounces around

I think if most of us got 6+ inches of winter, we would call that a decent storm. We should always try to lead with our head and not our heart as there is always that level of disappointment. I look at anything above 6” as a bonus

My wife already booked a hotel for this week so she can get down town to children’s for work before the hospital fills it up.

Sorry, storm is canceled.

2 more weeks

Day 4 WSSI is already highlighting major impacts for portions of the area

pretty notable this far out

Hope 00z models are good. Has storm been sampled?