White Christmas Blizzard 2022

[fyrfyter]

The Euro gives 0.5” on Friday. The NAM runs out of time before the system exits. What are you looking at?

[mikeyp]

6EC8CD6F-2246-4BBD-998D-B7B9C80ED81F.png

[tron777]

Good morning all! Well it appears the slight eastern ticks continue with this system. Models continue to delay the strengthening process so the more that happens, the more it will come east. The 6Z NAM is the furthest east with the low over us. Euro is still the furthest west with the low cutting thru Eastern IN. So we may have the goal posts narrowing even more. Should the trend continue today, them hmmmm.... in terms of snowfall amounts. Of course, no one should change a thing at this time. The energy should be fully sampled tonight wit the 0Z package.

[Bgoney]

EPS track cluster have tightened up with the low moving Into central Indiana, it's where the low goes from there that could add a small addition amount of snow to the 1-3 that many have put an early forecast on. If it heads more ENE, we stay in the snow showers longer, if it heads NE, I don't think it changes anything in the snow dept

[dce]

The Euro gives 0.5” on Friday. The NAM runs out of time before the system exits. What are you looking at?

Here is the same Euro run through about Sunday. And that isn't Kuchera. It's just 10:1. Ratios would give more accumulation than what is shown.

[fyrfyter]

The Euro gives 0.5” on Friday. The NAM runs out of time before the system exits. What are you looking at?

Here is the same Euro run through about Sunday. And that isn't Kuchera. It's just 10:1. Ratios would give more accumulation than what is shown.

Look at that- it still shows 1” for Cincinnati… am I missing something?

[tron777]

EPS track cluster have tightened up with the low moving Into central Indiana, it's where the low goes from there that could add a small addition amount of snow to the 1-3 that many have put an early forecast on. If it heads more ENE, we stay in the snow showers longer, if it heads NE, I don't think it changes anything in the snow dept

That is the key... perfect post! A longer ramping up of the system will take it more East versus a quicker ramping up which pulls it more North and sometimes NW as we've seen on some solutions.

[tron777]

It's about time to break out the SREF Plumes for this system. 9Z run I believe is just starting so I'll post on the overnight 3Z run for now. At CVG, the ranges are 0.02" of snow to over 6". The mean is 2.25". The SREF plumes to me are useful if you pay attention to where the better clustering is of the different members. Just like you would use an Ensemble mean like the GEFS or EPS. The SREF plumes hold that same value. Here's the link I use if you need it if you want to check DAY, MGY, CMH, ILN etc etc. for yourself. Lot of cool things to look at even besides snowfall totals.

https://www.spc.noaa.gov/exper/sref/srefplumes/

[dce]

The Euro gives 0.5” on Friday. The NAM runs out of time before the system exits. What are you looking at?

Here is the same Euro run through about Sunday. And that isn't Kuchera. It's just 10:1. Ratios would give more accumulation than what is shown.

Look at that- it still shows 1” for Cincinnati… am I missing something?

No, you're not wrong.. If you look at the Kuchera map it does give Cincy much more than 1 inch. I'm not saying that is right, but it could be. Also, the entire state of Ohio isn't dry slotted by the Euro. We really are very close to a nice event. Right on the edge either way.

[cloudy72]

It's about time to break out the SREF Plumes for this system. 9Z run I believe is just starting so I'll post on the overnight 3Z run for now. At CVG, the ranges are 0.02" of snow to over 6". The mean is 2.25". The SREF plumes to me are useful if you pay attention to where the better clustering is of the different members. Just like you would use an Ensemble mean like the GEFS or EPS. The SREF plumes hold that same value. Here's the link I use if you need it if you want to check DAY, MGY, CMH, ILN etc etc. for yourself. Lot of cool things to look at even besides snowfall totals.

https://www.spc.noaa.gov/exper/sref/srefplumes/

9z is in! Up to 2.99" average for CVG now. Moving in the right direction!

[cloudy72]

Other 9z sites:

DAY = 3.70"
CMH = 1.79"
IND = 4.53"

[tron777]

It's about time to break out the SREF Plumes for this system. 9Z run I believe is just starting so I'll post on the overnight 3Z run for now. At CVG, the ranges are 0.02" of snow to over 6". The mean is 2.25". The SREF plumes to me are useful if you pay attention to where the better clustering is of the different members. Just like you would use an Ensemble mean like the GEFS or EPS. The SREF plumes hold that same value. Here's the link I use if you need it if you want to check DAY, MGY, CMH, ILN etc etc. for yourself. Lot of cool things to look at even besides snowfall totals.

https://www.spc.noaa.gov/exper/sref/srefplumes/

9z is in! Up to 2.99" average for CVG now. Moving in the right direction!

Good morning Mike! Missed you posting around here lately so glad to see you're back. That was nice to see only 1 dud member remaining. We can of course chop the weenie solutions off as well. Nice cluster in that 1.5 to 3.5" range. You do an avg of that cluster which is 2.5" and that is right inline with the current forecast. I'll take it!

[young pup]

Thought I would share this. A friend includes me on his weather service. This is from Weather works. High Impact Winter Weather Event Likely Thursday Night Into Friday... A quiet next few days in store, but all eyes are on a potent disturbance that will impact the area starting Thursday Night. Given we are still a few days out from the start, the exact details still need to be sorted out. One thing we are certain about is that a very powerful and dangerous shot of arctic air will cause a rapid drop in temps overnight Thursday after some evening rain. We are talking a drop of 30 - 40 degrees in just a matter of a few hours that will instantly cause all wet surfaces to freeze. On top of that, a period of snow is likely (preliminary change over time is 1 - 4AM) that leads to some accumulation through Friday Morning. Preliminary estimates are for 2 - 5" of snow that will likely be blown around in the wind. In addition, temps crashing to the single digits will basically make salt ineffective, which will lead to extra operations being needed.

[cloudy72]

Good morning Mike! Missed you posting around here lately so glad to see you're back. That was nice to see only 1 dud member remaining. We can of course chop the weenie solutions off as well. Nice cluster in that 1.5 to 3.5" range. You do an avg of that cluster which is 2.5" and that is right inline with the current forecast. I'll take it!

Thanks, Les! Been really busy with work and personal life and throw in some bouts of sickness. Hopefully all is well now!

[fyrfyter]

floop-ecmwf_full-2022122006.prateptype_cat_ecmwf.conus.gif

6z Euro low track

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Still low on the accumulations for us.

[cloudy72]

Thought I would share this. A friend includes me on his weather service. This is from Weather works. High Impact Winter Weather Event Likely Thursday Night Into Friday... A quiet next few days in store, but all eyes are on a potent disturbance that will impact the area starting Thursday Night. Given we are still a few days out from the start, the exact details still need to be sorted out. One thing we are certain about is that a very powerful and dangerous shot of arctic air will cause a rapid drop in temps overnight Thursday after some evening rain. We are talking a drop of 30 - 40 degrees in just a matter of a few hours that will instantly cause all wet surfaces to freeze. On top of that, a period of snow is likely (preliminary change over time is 1 - 4AM) that leads to some accumulation through Friday Morning. Preliminary estimates are for 2 - 5" of snow that will likely be blown around in the wind. In addition, temps crashing to the single digits will basically make salt ineffective, which will lead to extra operations being needed.

Great post! Also something to think about for Friday are all the last minute Christmas shoppers clogging the roads. With all the stress and the need to rush I can only imagine how many wrecks there might be! I for one plan on staying home and watching things unfold from my recliner! LOL

[young pup]

Thought I would share this. A friend includes me on his weather service. This is from Weather works. High Impact Winter Weather Event Likely Thursday Night Into Friday... A quiet next few days in store, but all eyes are on a potent disturbance that will impact the area starting Thursday Night. Given we are still a few days out from the start, the exact details still need to be sorted out. One thing we are certain about is that a very powerful and dangerous shot of arctic air will cause a rapid drop in temps overnight Thursday after some evening rain. We are talking a drop of 30 - 40 degrees in just a matter of a few hours that will instantly cause all wet surfaces to freeze. On top of that, a period of snow is likely (preliminary change over time is 1 - 4AM) that leads to some accumulation through Friday Morning. Preliminary estimates are for 2 - 5" of snow that will likely be blown around in the wind. In addition, temps crashing to the single digits will basically make salt ineffective, which will lead to extra operations being needed.

Great post! Also something to think about for Friday are all the last minute Christmas shoppers clogging the roads. With all the stress and the need to rush I can only imagine how many wrecks there might be! I for one plan on staying home and watching things unfold from my recliner! LOL

I'm dreading working that day. Needless to say with windchills being that low, only walks up to the businesses front doors will be serviced.

[tron777]

Good morning JP! That's a pretty good summary there as to what's going on. Nice find. We'll see if we get NAM'ed again here shortly.

[tron777]

Good morning Mike! Missed you posting around here lately so glad to see you're back. That was nice to see only 1 dud member remaining. We can of course chop the weenie solutions off as well. Nice cluster in that 1.5 to 3.5" range. You do an avg of that cluster which is 2.5" and that is right inline with the current forecast. I'll take it!

Thanks, Les! Been really busy with work and personal life and throw in some bouts of sickness. Hopefully all is well now!

Good deal! It's time for you to get off the bench and get back into the game here.

[young pup]

Good morning JP! That's a pretty good summary there as to what's going on. Nice find. We'll see if we get NAM'ed again here shortly.

Good morning Les. Going to be an interesting day on the model runs.

[tron777]

floop-ecmwf_full-2022122006.prateptype_cat_ecmwf.conus.gif

6z Euro low track

39D5BFE0-F093-4173-9B02-751A9F4079B5.jpeg

Still low on the accumulations for us.

It is still the lowest model for accumulations, but a step in the right direction. 1" on the old run to almost 2" on the new run. Baby steps, right? Seriously though, it's sooo close to becoming something a bit better in terms of snowfall accumulations. Everything else, as we already know will be very high impact.

[tron777]

Good morning JP! That's a pretty good summary there as to what's going on. Nice find. We'll see if we get NAM'ed again here shortly.

Good morning Les. Going to be an interesting day on the model runs.

I'm strapped in and ready!

[cloudy72]

Found this interesting forecast on the SREF site - the 9z run (this would be late THU night into early FRI). 30-50% probs of 1"+ per hour snow rates.

SREF_SNOWRATE_1INCH__f069.gif

[tpweather]

Good Morning Les. Have not looked at any models this morning and will busy until probably 3 or 4pm. Hopefully models are getting rather close together. Where does the northern piece of energy close off. Is that Iowa which gives us the smallest amount or does close off in southern Missouri. It may wait even longer if this push of cold air comes in quicker. Still believe a low forms on the front well south. Not sure of the strength but it can add a little more moisture to this system. Fun times ahead and will be ready later today.Going to stay for the NAM output and then back much later today

[tron777]

Good morning Tim! While we await the NAM, a wonderful overnight AFD from the boys:

A significant winter storm is poised to affect the Great Lakes and
Ohio Valley with multiple hazards as we head into the end of the
workweek into the Christmas holiday weekend.

But before we delve into the upcoming storm system, we will first
talk about the immediate long term for Wednesday night into
Thursday. A lead s/wv and and associated isentropic lift will bring
a round of mainly rain to the region late Wednesday night into
Thursday. Temperatures will bottom out in the evening Wednesday,
then slowly rise overnight. Depending how fast the pcpn arrives
versus warming surface temperatures will dictate if any p-type is of
a wintry mix. As of now, it appears a mix p-type is a low risk
probability. The highest chance for pcpn with this feature will
occur on Thursday, with the highest PoPs over our eastern CWFA. Lows
Wednesday night will range from the upper 20s to the lower 30s.
Highs on Thursday will range from the lower to upper 40s.

As has been advertised, a significant upper level low will be
deepening as it digs southeast from the central Plains eastward into
the Great Lakes and Ohio Valley Thursday into Friday. This process
will result in surface cyclogenesis with the low pressure deepening
from southern/south central Indiana at 00Z Friday to a position
north of Lake Ontario 00Z Saturday. WAA ahead of the cold front,
Arctic in nature, will change rain over to a period of snow behind
the front Thursday night. Although snow amounts at this time
look to be anywhere from 0.50" to perhaps up to 1.50", the rain
change over to snow with very rapidly falling temperatures from
above freezing to below freezing may result in potential flash
freeze conditions. This will be aided with the development of
strong winds in the wake of the front which will be gusting
anywhere from 40 mph south to at least 55 mph far north late
Wednesday night. The rapidly falling temperatures and winds will
create dangerously low wind chill readings. This first batch of
snow will likely be limited in blowing potential due to it
initially starting out in a wet state, becoming crusted over
quickly due to the quick falling temperatures. Lows by Friday
morning will range from near 0 west to near 10 east.

On Friday, wrap around moisture and lift perhaps aided by the 700 mb
low track will bring snow showers, scattered snow south and
most numerous north. There remains uncertainty how much snow
will fall given the available QPF and very likely SLRs of 15:1
to 20:1. The current forecast calls for about 0.25" south of the
Ohio River to possibly as much as 2" in west central Ohio.
These amounts, and the continued very strong winds (40 mph south
to 55 mph+ north) will be the key as to how widespread the
blowing snow will be. Right now, the best chance of the region
to see the worst conditions would be east central Indiana
northeast into parts of central Ohio (the strongest winds and
the best chance to have appreciable snow to blow). Temperatures
will show little rise during the day, so dangerously low wind
chills will continue. Much discussion has been done with the
Weather Prediction Center and our surrounding WFOs as to what to
do about potential headlines at this juncture. There`s no
question that there will be a need for winter headlines (snow,
icy roads, winds, wind chills) at some point which will at least
meet advisories level. It is whether any of our area,
particularly east central Indiana northeast into central Ohio
will get the needed snow to trigger a Winter Storm Watch or
Warning which would not be based on meeting snow amount
criteria, but meeting an impact criteria, from the blowing snow
and low visibility. Given that this is the 7th period and
confidence is not high enough on snow amounts, have opted to
hold off on a Watch for this forecast package. However, will
continue to highlight all the hazards in our HWO product.

As we head into Friday night into Saturday, snow showers will taper
off as the center of the main upper low shifts north and east. It
will still remain very cold and windy. Lows Friday night will range
from the single digits east to near 5 below west. Highs on Saturday
will range from the mid teens east to the single digits west. Wind
chill readings will mostly certainly reach advisory criteria all
locations Friday into Friday night. Some values will come close to
Warning criteria in east central Indiana and west central Ohio (25
below).

Winds will begin to taper down as we head into Christmas Eve night
into Christmas Day Sunday as Arctic high pressure builds east into
the Ohio Valley. It will continue to be very cold with lows in the
single digits to a few degrees below zero Christmas morning to highs
10 to 20 on Christmas day with skies eventually becoming partly
cloudy.

A fast moving, but weak system, may affect the region by Monday.
Will have a low chance of light snow. Highs will rebound into the
mid and upper 20s.