Historic Christmas Cold & maybe snow?! Dec 23rd-30th

[Stovepipe]

16 minutes ago, ShawnEastTN said:

What is interesting to me if snow amounts are more even a small amount more say 3" with the wind as strong as its going to be and the powdery nature of this type of snow, there could be times of serious visibility issues with near whiteout conditions from blowing snow. Would be amazing to see if we end up with more than currently forecast.

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I believe it was in Feb '14 or possibly '15 when we had a surprise inch fall at 20 degrees.  I saw more wrecks during that event that any other in memory.  Granted Knox county didn't bother to put down salt, not that it would have helped a whole lot at those temps, but still.  If the Kuchera ratios of 24 to 1 posted earlier are accurate, what little QPF we do get will me maximized and roads will be wild.

[Stovepipe]

The 21z RAP is coming in colder.  Has TYS at -4 Friday morning with a -22 wind chill.  It's also dryer than other modeling.

[Carvers Gap]

If we had 5-6" of snow on the ground w/ this air mass, we would make a run at the all time record low.

[Daniel Boone]

7 minutes ago, Stovepipe said:

The 21z RAP is coming in colder.  Has TYS at -4 Friday morning with a -22 wind chill.  It's also dryer than other modeling.

Let's just hope it's wrong. 

[Daniel Boone]

3 minutes ago, Carvers Gap said:

If we had 5-6" of snow on the ground w/ this air mass, we would make a run at the all time record low.

Yeah, definitely makes a difference. Each ever recorded record cold featured good snowpack. One exception I can think of is the Christmas '83 outbreak. Dry as a bone but, the high was Zero where I lived at the time in Pennington gap. I can only speculate how cold it would have been had there been snowpack. 

[dwagner88]

2 hours ago, Runman292 said:

Speaking of historical cold, when was the last time all of TN had a wind chill warning?

This is for sure the first one in Chattanooga. We’ve had a watch before (I think in 2014). 

[PowellVolz]

MRX is also having to deal with not knowing how much moisture these cold temps wring out. I also wonder if the high res simulated radars can pick up on a very low DGZ. Obviously this won’t be a big snow maker but I’m very curious how the mod’s handle some of these variables that we don’t ever see in our area.


.

[John1122]

A half inch to 5+ is my modeled range 48 hours out. That's how crazy this system is. 

[Dsty2001]

Regardless of snow, with such fast drop in temps and the winds forecasted, I hope nobody loses power.  That's my biggest concern at the moment, any precipitation will just complicate that factor

[TellicoWx]

[TellicoWx]

A little nowcasting out west vs modeled....Globals are underperforming vs meso models for North Nebraska. Currently snow squall warning (GFS had 1/2"). Reality...

[Scottie16]

1 minute ago, TellicoWx said:

2 minutes ago, TellicoWx said:

Albeit I hate that this cold could be disastrous for some, I’m excited to track it as it moves into the area; Mostly to see the battle of cold air rushing off the plateau into the Valley.

[TellicoWx]

Mesoscale Discussion 2056
   NWS Storm Prediction Center Norman OK
   0315 PM CST Wed Dec 21 2022

   Areas affected...southern Wyoming...southwest South Dakota...western
   Nebraska...and northern Colorado

   Concerning...Snow Squall 

   Valid 212115Z - 220015Z

   SUMMARY...Snow squalls will persist into the evening across portions
   of the central Rockies and central High Plains.

   DISCUSSION...A very strong arctic front continues to move south
   across the central High Plains with temperature gradients of 40-50F
   along the front. Several bands of snow have developed near the
   vicinity of this front with moderate to heavy snow being observed.
   In addition, winds are very strong with 30-40 knot winds both north
   and south of the front with observed gusts in excess of 50 knots. 

   These winds, combined with multiple bands of snow have led to snow
   squall conditions across much of Wyoming and southwest South Dakota
   this afternoon. These conditions continue to shift south with the
   surface front. Observed visibility restrictions have been greatest
   north of the front, likely due to drier snow amid temperatures in
   the -10 to -20F range and 30+ kt sustained winds. In fact, blizzard
   conditions have been observed at 8 ASOS/AWOS sites across Wyoming,
   South Dakota, and Nebraska in the past 2 hours. Expect similar
   conditions to spread into northern Colorado this evening.

[1234snow]

Mesoscale Discussion 2056  NWS Storm Prediction Center Norman OK  0315 PM CST Wed Dec 21 2022  Areas affected...southern Wyoming...southwest South Dakota...western  Nebraska...and northern Colorado  Concerning...Snow Squall   Valid 212115Z - 220015Z  SUMMARY...Snow squalls will persist into the evening across portions  of the central Rockies and central High Plains.  DISCUSSION...A very strong arctic front continues to move south  across the central High Plains with temperature gradients of 40-50F  along the front. Several bands of snow have developed near the  vicinity of this front with moderate to heavy snow being observed.  In addition, winds are very strong with 30-40 knot winds both north  and south of the front with observed gusts in excess of 50 knots.   These winds, combined with multiple bands of snow have led to snow  squall conditions across much of Wyoming and southwest South Dakota  this afternoon. These conditions continue to shift south with the  surface front. Observed visibility restrictions have been greatest  north of the front, likely due to drier snow amid temperatures in  the -10 to -20F range and 30+ kt sustained winds. In fact, blizzard  conditions have been observed at 8 ASOS/AWOS sites across Wyoming,  South Dakota, and Nebraska in the past 2 hours. Expect similar  conditions to spread into northern Colorado this evening.

I think this would qualify as a “Blue Norther”! Except for the whole country. In this map is a observation of 52 degrees in Colorado. Which will below 0 very shortly.

The 18z HRRR was very very cold Friday morning. It shows -15 up on Black Mountain on the KY/VA border. -10 or lower for the Plateau and SWVA. -3 around Chatty. -4 for Knoxville. -5 - -7 for TRI. Below 0 for the whole state.

I really hope the HRRR is about 10 degrees too cold for the whole state. But we have saw the cold be deeper behind these fronts in the past.

[TellicoWx]

Wild videos being posted of this fropa going thru Denver...people reporting what appeared to be a frozen haboob (sky cams back up the reports). 30-40° temp drops in 30 mins.

[Scottie16]

Euro has been trending southward every so slightly every run. HRRR has the low more south as well. 

[ShawnEastTN]

Euro has been trending southward every so slightly every run. HRRR has the low more south as well. 

Hope that trends that way all the way up to the event, the further south the closer we are to the dynamics and deeper moisture. Would love for this storm to blow modeling up collectively. Happens every so often with winter storms, especially powerful atypical type storms.

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[TellicoWx]

Considering the front range of the Rockies is prone to wild temp swings...this is remarkable. Fastest 1 HR temp drop ever recorded at Denver International.

[Scottie16]

Adding to what TellicoWX is posting 

 

 

[TellicoWx]

2 minutes ago, Scottie16 said:

Adding to what TellicoWX is posting 

 

 

According to NWS Boulder, the interstate almost instantly froze over...most areas reporting 1"-2". If CODOT can't handle an inch or two, doesn't bode well for TDOT (assuming models are close to correct on plateau/west).

[Scottie16]

2 minutes ago, TellicoWx said:

According to NWS Boulder, the interstate almost instantly froze over...most areas reporting 1"-2". If CODOT can't handle an inch or two, doesn't bode well for TDOT (assuming models are close to correct on plateau/west).

Im curious to see how MRX will adjust seeing how strong the front is now. The HRRR is at hour 22 and it finally shows the cold ahead of the front. Precip field seems to still hold. 

[Scottie16]

Also TX, I Think Colorado airport set the record for temperature drop in a hour. Going from 47• to 1•. I saw a couple of post that showed a 60 degrees change in feel like temperature..

[fountainguy97]

Unfortunately ugly trends today for most. This arctic air mass sucks the life out of our moisture way too fast. It's a curse in disguise really. 

Parent low too far north so we can't tap into any extra NW flow energy.
 

Not a non-event by any means! But this will be a pretty brief 1-2hr changeover to snow before the moisture dries up. 
 

fun fact: this will be by far the slowest start to winter in the short 4 years I've been here. (I know we have been spoiled the last few decembers. Still makes me sad lol)

 

[Scottie16]

5 minutes ago, fountainguy97 said:

Unfortunately ugly trends today for most. This arctic air mass sucks the life out of our moisture way too fast. It's a curse in disguise really. 

Parent low too far north so we can't tap into any extra NW flow energy.
 

Not a non-event by any means! But this will be a pretty brief 1-2hr changeover to snow before the moisture dries up. 

 

Looking at the flow west, the HRRR didn’t have that solution at all until the 18Z run. That’s a positive in the ugly trend.

[ShawnEastTN]

Unfortunately ugly trends today for most. This arctic air mass sucks the life out of our moisture way too fast. It's a curse in disguise really. 
Parent low too far north so we can't tap into any extra NW flow energy.
 
Not a non-event by any means! But this will be a pretty brief 1-2hr changeover to snow before the moisture dries up. 
 
fun fact: this will be by far the slowest start to winter in the short 4 years I've been here. (I know we have been spoiled the last few decembers. Still makes me sad lol)


 

Yeah I don't like most of the modeling trends this evening, but really think we are in for some surprises with this storm. I think the odds are higher for a surprise because historically surprises come in 2 flavors, very weak systems, and insanely over amped systems. Doesn't mean we'll get a surprise but a possibility. I think someone in the region is going to score well beyond what's modeled/forecast.

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[TellicoWx]

8 minutes ago, ShawnEastTN said:

Yeah I don't like most of the modeling trends this evening, but really think we are in for some surprises with this storm. I think the odds are higher for a surprise because historically surprises come in 2 flavors, very weak systems, and insanely over amped systems. Doesn't mean we'll get a surprise but a possibility. I think someone in the region is going to score well beyond what's modeled/forecast.

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Agree..honestly don't think any modeling had a handle on this thing good or bad (based off what's currently going on out west and the bad misses out that way). With the system being so anomalous, don't think the coding is equipped for it. Ex. how often do we see the DGZ sitting on the ground in this region? 

[Scottie16]

12 minutes ago, ShawnEastTN said:

Yeah I don't like most of the modeling trends this evening, but really think we are in for some surprises with this storm. I think the odds are higher for a surprise because historically surprises come in 2 flavors, very weak systems, and insanely over amped systems. Doesn't mean we'll get a surprise but a possibility. I think someone in the region is going to score well beyond what's modeled/forecast.

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So far. The nam is showing more QPF for the western part of the state. 

[TellicoWx]

Just now, Scottie16 said:

So far. The nam is showing more QPF for the western part of the state. 

Wouldn't be surprised SREF looked a tad better when I did a quick glance.

[TellicoWx]

Keep thinking back to the Birmingham Snowmaggedon (one where Span had to walk to work cause he forecasted no problems and 1/2" of snow or so brought Birmingham to a standstill)

[Kasper]

Ok guys and gals, here’s an idea to moisten up the atmosphere, just before fropa passage…… everyone step outside and unload your bladder into the great outdoors!