December 21st-24th, 2022 | Plains/MW/GL/OV Winter Storm

[CIWeather]

IND has already issued a Special Weather Statement for the storm...

Quote

Special Weather Statement National Weather Service Indianapolis IN 251 PM EST Sun Dec 18 2022 INZ021-028>031-035>049-051>057-060>065-067>072-191000- Carroll-Warren-Tippecanoe-Clinton-Howard-Fountain-Montgomery- Boone-Tipton-Hamilton-Madison-Delaware-Randolph-Vermillion-Parke- Putnam-Hendricks-Marion-Hancock-Henry-Vigo-Clay-Owen-Morgan- Johnson-Shelby-Rush-Sullivan-Greene-Monroe-Brown-Bartholomew- Decatur-Knox-Daviess-Martin-Lawrence-Jackson-Jennings- Including the cities of Delphi, Flora, Williamsport, West Lebanon, Lafayette, West Lafayette, Frankfort, Kokomo, Attica, Covington, Veedersburg, Crawfordsville, Lebanon, Zionsville, Tipton, Fishers, Carmel, Noblesville, Anderson, Muncie, Winchester, Union City, Farmland, Parker City, Clinton, Fairview Park, Rockville, Montezuma, Rosedale, Greencastle, Plainfield, Brownsburg, Danville, Indianapolis, Greenfield, New Castle, Terre Haute, Brazil, Spencer, Gosport, Martinsville, Mooresville, Greenwood, Franklin, Shelbyville, Rushville, Sullivan, Carlisle, Shelburn, Farmersburg, Linton, Bloomfield, Jasonville, Worthington, Bloomington, Nashville, Columbus, Greensburg, Vincennes, Washington, Loogootee, Shoals, Bedford, Mitchell, Seymour, and North Vernon 251 PM EST Sun Dec 18 2022 ...

SIGNIFICANT WINTER STORM TO IMPACT THE STATE THURSDAY THROUGH THE HOLIDAY WEEKEND... A significant storm system is expected to move through the area Thursday through the weekend with heavy rain, accumulating snow, high winds, sub zero temperatures, and dangerously low wind chill all possible across Indiana during that time frame. While confidence remains low on exact details of timing and track of the system and areas where heavy snow could fall, confidence remains high in the dangerously cold air threat and high wind potential. Early look at confidence for potential winter storm:

Areas of higher confidence: * Period of high winds with a wind shift to the northwest Thursday into Friday * Extremely cold arctic air this weekend with temperatures falling below zero * Dangerous wind chills possibly down to -20F to -30F this weekend * Periods of snow showers on the backside of the system Friday into Saturday

Areas of lower confidence: * Exact storm track and where areas of heavy snowfall could set up * Snowfall amounts remain very uncertain at the moment, higher confidence in accumulating snow further north and west * Temperatures Thursday into Friday, could vary significantly across short distances through the state depending on track of the system People need to stay alert to the forecast and the possible changing weather conditions through the week. Be prepared for potential travel impacts.

 

[Indygirl]

That’s the warning I just got on my radar app. 

[snowlover2]

ILN

Quote

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Little to discuss for Tuesday and even the beginning of Wednesday as
quasi-zonal H5 flow persists over a surface high pressure system.
Temperatures do get closer to climatological normals for Tuesday but
likely still come up a bit short.

High pressure gets booted to the northeast on Wednesday and a thick
shield of cirrus clouds will build in from the west ahead of the
next major low pressure system. The latest 12z model/ensemble runs
do seem to move this system in a bit slower compared to previous
runs. As of now, pcpn intensity/coverage appears to be more limited
Wednesday night and Thursday during the daytime hours with primarily
weak, isentropic lift in place. During this period, bufkit soundings
suggest more saturation below the DGZ, along with a well-defined
warm nose below near/below 5000 ft AGL. This should result in
primarily liquid pcpn reaching the surface. Depending on how surface
temperatures trend, it is plausible that some freezing rain/drizzle
could sneak in, especially NW of I-71. The Euro seems to favor a
warmer forecast (primarily rain) while the GFS is a bit cooler at
the surface. Still kept rain/snow mention in for Wed night/Thursday
until confidence is high enough on whether to include additional p-
types.

As we progress into Thursday night, forcing becomes more
concentrated ahead of the surface cold front. Models suggest a sharp
transition zone from rain to snow as the cold air surges in Thursday
night, limiting the potential for a prolonged period of mixed pcpn.
As of now, best chance for accumulating snowfall will be during this
overnight period and continue into Friday morning. In our CWA, the
general trend amongst ensembles/deterministic models is to keep snow
accumulations to less than a few inches. However, additional energy
continues to pivot around the back side of the low pressure system,
resulting in additional snow accumulations Friday through Friday
night. This could result in a couple more inches for some locations.
While snow will certainly be impactful to travel plans, there is
also a concern for the wind enhancement that will occur as we
progress through Friday and Friday night. Ensembles suggest high
confidence that winds will gust in excess of 40 mph for pretty much
all of our CWA. Some locally higher gusts will also be possible,
especially towards eastern IN and west-central OH, which is
something we will continue to monitor closely and message
appropriately.

High confidence in an Arctic-like air mass settling in for Friday
and persisting through the weekend. The strong, synoptic winds will
provide some bitterly cold wind chills Friday night into Saturday.
The `feels like` temperature looks to be sub-zero everywhere Friday
night, with wind chills potentially dipping into the negative teens
and even to near -20 for our western counties. Sub-zero wind chills
will continue to be a factor most of Saturday as breezy conditions
persist and high temperatures remain in the single digits to middle
teens range.

 

 

[MesoscaleBanding]

WPC

[Indygirl]

Channel 6 met just issued the same warning on Facebook. 
Looks like they pulled the trigger to be on the safe side. 
Indiana 

 

Edited December 18, 2022 by Indygirl

[CIWeather]

Henry's map...

Quote

 

There is no doubt we have not seen a storm like in several decades. I termed the storm a “Polar Vortex Superstorm” only because we need to get the word out that we are dealing a very unusual and rare event. The storm is rare because of the combination of extremely cold, arctic air with high winds and heavy snow. The combination of wind and temperatures will result in dangerous wind chills well below zero.

As I mentioned, this is a storm not to play around with because it will be life-threatening if you are not prepared for the extreme conditions. I am sure this week you will hear more about just how dangerous a storm like this will be.

The high winds alone will be gusting to 60 mph which will result in power outages. Even east of the Appalachians, what I term, “Wind Breaking High Wind Event” will occur Friday as the cold air comes over the mountains and rushes into the mid-Atlantic resulting in wind gusts 60-80 mph.

The heaviest snow, if you can measure it, will go from Illinois into the Great Lakes. That area will see over a foot of snow with heavy drifting.

Road closures will occur. In addition, the plummeting temperatures behind the cold front will cause flash freezes from the Northeast to the southern Plains.

 

 

Edited December 18, 2022 by CIWeather

[RobB]

1 minute ago, CIWeather said:

Henry's map...

 

Polar Vortex Superstorm.  That's Henry alright 🙂

[MesoscaleBanding]

Just now, CIWeather said:

Henry's map...

 

Why does his graphic say Tuesday/Wednesday 🤦🏻‍♂️? He's going to confuse/panic people that don't know any better💩

[CIWeather]

Just now, MesoscaleBanding said:

Why does his graphic say Tuesday/Wednesday 🤦🏻‍♂️? He's going to confuse/panic people that don't know any better💩

Good call on that. I didn't even catch that!

[Pros3lyte]

3 minutes ago, CIWeather said:

Henry's map...

 

Good gravy. Worrisome for many families with little ones who may lose power

 

edit: just worrisome for many folks in general

Edited December 18, 2022 by Pros3lyte

[Indygirl]

I think all online weather groups had a meeting together today lol.

All of the Facebook groups putting out warnings now. 

[CIWeather]

Henry just updated it. Here's the updated one...

[Wnwniner]

1 minute ago, Indygirl said:

I think all online weather groups had a meeting together today lol.

All of the Facebook groups putting out warnings now. 

If you're not first, your last...

[SOMOSnow]

18z NAM at hour 84 with 24 hour snowfall looks to be way South.

[beaver56]

17 minutes ago, CIWeather said:

Henry just updated it. Here's the updated one...

I am hoping the heavier snow band expands SE a bit witha track like that. 

[vespasian70]

All I want is a white Christmas no matter the outcome...as long as the power stays on!!

[Pros3lyte]

Wow. DTX tossing out the heavy pretty early…

 

 

“The focus will then turn to the evolution of the western Canadian upper trough as several PV anomalies (namely a very large one now dropping south through Alaska today) dig into the northwest CONUS and begin the process of what will be a significant amplification of this upper trough, especially as the consolidated stream of PV digs through the central Rockies into the High Plains by Thursday. The west to east orientation of the longwave pattern over NOAM seems very conducive for the development of a major winter storm in/around the region as this area of PV works through the central CONUS and pivots northeast into the Great Lakes by Friday. In fact, given the strengthen of the upper jet stream driving this whole process (nearing 190-200 knots at the H3 level) and the degree of arctic air in place to phase into the system, this could very well end up being a historic winter storm for the region, depending on the evolution of potent surface cyclogenesis (970-975mb) as the system matures and occludes somewhere in Ohio Valley to southern/central Great Lakes. While other model solutions such as the main cyclogenesis ending up west over the Mississippi Valley or conversely energy shifting east and leading to east coastal storm development are not necessarily off the table at the Day 5 forecast, model consensus from the 12z cycle has further tightened to suggest the main development of the cyclone will occur in the general vicinity of the central/southern Great Lakes. So, even at Day 5, the confidence has increased quite a bit in this idea. Perusing the wide view of both the GOES E and W water vapor imagery this afternoon does not seem to yield any obvious "surprises" that would disrupt this generally expected outcome in any major way. In other words, at this point, it seems like a relatively straightforward upper level pattern within which this winter storm will evolve. Even with this increased confidence, the higher end intensity of this expected cyclone will lead to widely varying weather conditions in and around the storm center so the exact placement and size of the surface low will be very critical in how significant the winter impacts will be over lower Michigan. The worse case (and honestly quite realistic) scenario would be life threatening winter storm conditions (essentially a blizzard) if the heavy snow, strong winds and bitter cold air come together over the area as the potential bombing phase of the cyclogenesis occurs. Less severe conditions would occur if this low were to form such that the area is "dry slotted, warm slotted, or both" and the precipitation intensity is diminished/disrupted and the colder air and strongest winds are delayed/disrupted to some degree. A weaker evolution of the surface cyclone could also theoretically lessen the impacts to a more typical moderate or strong winter storm. Even with all of these considerations, the forecast strength of this system suggests that impacts should be relatively significant for the area even if all factors do not come together ideally for a winter storm focused over/near the immediate forecast area. Details of this expected winter storm will be refined during the upcoming week as the most important features associated with the development of this system become better sampled from our various remote sensing networks. Expect potentially significant variations of precipitation type/timing and wind speed forecasts over the coming days as the forecast for the positioning/strength of this winter storm comes together with time. Suffice it to say, this storm has a potential to be very disruptive for holiday travel heading into the weekend. With a substantial shot of arctic air funneling into the region with and in the wake of the system, hazardous conditions will likely extend out several days from the main "event" which seems to be center on Thursday night into Friday at this time. &&”

Edited December 18, 2022 by Pros3lyte

[CIWeather]

Chicago already throwing out the phrase "crippling blizzard" in their AFD...

Quote

Tuesday through Sunday... All eyes in the long term period are on the late week cyclone and intrusion of bitterly cold air along with dangerous wind chills late this week into the weekend. Confidence continues to steadily increase that a potentially crippling blizzard could impact portions of the region later this week, the timing of which couldn`t be worse for holiday travel. If, and how severely, our forecast area (CWA) will be impacted depend on the exact track of the cyclone and to some extent the magnitude and timing of the forecast rapid deepening. Medium range guidance has been advertising a powerful cyclone spinning up over the Great Lakes or northeast U.S. for days now, with a pretty sizable spread in where the storm will develop/track. There was a cluster of guidance favoring a Great Lakes target region, which would increase chances for major impacts in our CWA, with a second cluster favoring the New England resulting in disruptive, but far less extreme winter weather locally. Trend in ensemble guidance over the past 48 hours has been decidedly away from a New England cyclone and toward cyclogenesis farther west over the Great Lakes with recent runs of the GFS/GEFS making the significant shift west. While track guidance has shown (pretty typical) variability, the theme of rapid, and potentially explosive, deepening of the cyclone has been a fairly consistent theme in guidance for days now. The expected intensity of the cyclone combined with the very strong arctic high (>1040mb) over the northern and central Plains leads to high confidence in a noteworthy high wind event with this system. The eventual track of the cyclone and timing of rapid/explosive deepening will determine where the very high impact winter weather/potential blizzard will set up. Given recent model and ensemble trends, our CWA lies very solidly within the potential threat region. The incipient wave that is forecast to spawn this system is still located north of Alaska across the Beaufort Sea, so it still has a lot of distance to cover with plenty of time for shifts in guidance. It isn`t uncommon for models to make leftward adjustments to the track of powerful cyclones like this, so it is important not to get locked in on a forecast track yet. At this distance, it is also advisable not to focus on individual operational runs of models, as operational runs will likely exhibit variability in the strength and especially track over the next couple or days. This run to run variability in operational runs is often not an actual "trend" but rather "noise" in the range of possibilities at this distance. Rather than focusing on noise level changes in operational runs, focusing on trends in ensemble data the next couple of days should prove more meaningful as we look to hone in on location and magnitude of the threat. In addition to producing blizzard conditions, the high winds will likely cause lakeshore flooding (which shore depends on track of cyclone) and dangerous wind chills well below zero. Currently, most guidance strongly supports advisory level wind chills (-20 to -30F) Friday into at least the first half of the Christmas weekend, with some potential for even a period of warning level (colder than -30F) wind chills as actual air temperatures plummet below zero. All indications are that our high temp Christmas Day will be the coldest since the mid 90s and possibly one of the top five coldest on record. Any power outages resulting from the strong winds greatly increase potential danger of the cold spell. We strongly urge everyone to pay close attention to later forecasts, particularly if you have holiday travel planned.

 

[DJKuo]

GFS model trend, from east KY to west KY

[beaver56]

Heavy snow is good,  but the risk of power outages is not great.

[CIWeather]

Just now, beaver56 said:

Heavy snow is good,  but the risk of power outages is not great.

And I think both are inevitable with this one...if things turn out the way that they are showing right now, that will be me.

[beaver56]

1 minute ago, CIWeather said:

And I think both are inevitable with this one...if things turn out the way that they are showing right now, that will be me.

For sure. I think the heavy snow will run from central IL to central OH. 6+ in most place.  Much like ensembles support. 

Edited December 18, 2022 by beaver56

[Hiramite]

Based solely on the fact the Lions just beat the Jets, this is going to be SE MI’s storm!!  

[Central Illinois]

28 minutes ago, vespasian70 said:

All I want is a white Christmas no matter the outcome...as long as the power stays on!!

I'd say theirs a good chance of power outages with this system 

[easton229]

27 minutes ago, Pros3lyte said:

Wow. DTX tossing out the heavy pretty early…

 

 

“The focus will then turn to the evolution of the western Canadian upper trough as several PV anomalies (namely a very large one now dropping south through Alaska today) dig into the northwest CONUS and begin the process of what will be a significant amplification of this upper trough, especially as the consolidated stream of PV digs through the central Rockies into the High Plains by Thursday. The west to east orientation of the longwave pattern over NOAM seems very conducive for the development of a major winter storm in/around the region as this area of PV works through the central CONUS and pivots northeast into the Great Lakes by Friday. In fact, given the strengthen of the upper jet stream driving this whole process (nearing 190-200 knots at the H3 level) and the degree of arctic air in place to phase into the system, this could very well end up being a historic winter storm for the region, depending on the evolution of potent surface cyclogenesis (970-975mb) as the system matures and occludes somewhere in Ohio Valley to southern/central Great Lakes. While other model solutions such as the main cyclogenesis ending up west over the Mississippi Valley or conversely energy shifting east and leading to east coastal storm development are not necessarily off the table at the Day 5 forecast, model consensus from the 12z cycle has further tightened to suggest the main development of the cyclone will occur in the general vicinity of the central/southern Great Lakes. So, even at Day 5, the confidence has increased quite a bit in this idea. Perusing the wide view of both the GOES E and W water vapor imagery this afternoon does not seem to yield any obvious "surprises" that would disrupt this generally expected outcome in any major way. In other words, at this point, it seems like a relatively straightforward upper level pattern within which this winter storm will evolve. Even with this increased confidence, the higher end intensity of this expected cyclone will lead to widely varying weather conditions in and around the storm center so the exact placement and size of the surface low will be very critical in how significant the winter impacts will be over lower Michigan. The worse case (and honestly quite realistic) scenario would be life threatening winter storm conditions (essentially a blizzard) if the heavy snow, strong winds and bitter cold air come together over the area as the potential bombing phase of the cyclogenesis occurs. Less severe conditions would occur if this low were to form such that the area is "dry slotted, warm slotted, or both" and the precipitation intensity is diminished/disrupted and the colder air and strongest winds are delayed/disrupted to some degree. A weaker evolution of the surface cyclone could also theoretically lessen the impacts to a more typical moderate or strong winter storm. Even with all of these considerations, the forecast strength of this system suggests that impacts should be relatively significant for the area even if all factors do not come together ideally for a winter storm focused over/near the immediate forecast area. Details of this expected winter storm will be refined during the upcoming week as the most important features associated with the development of this system become better sampled from our various remote sensing networks. Expect potentially significant variations of precipitation type/timing and wind speed forecasts over the coming days as the forecast for the positioning/strength of this winter storm comes together with time. Suffice it to say, this storm has a potential to be very disruptive for holiday travel heading into the weekend. With a substantial shot of arctic air funneling into the region with and in the wake of the system, hazardous conditions will likely extend out several days from the main "event" which seems to be center on Thursday night into Friday at this time. &&”

Wow, crazy for the usually conservative DTX this far out.