February 10-12, 2021 Winter Event

[jayyy]

High pressure will wedge down along the eastern slopes of the
Appalachians Wed with a CAD event expected to remain in place
through the entire event Fri. Southern stream moisture and jet
streak dynamics passing overhead Wed night will result in an
expansive area of precip, mainly snow, Wed night into Fri
morning. There have been some notable trends this morning,
mainly to slow down the onset of precip Wed, and thus, to delay
the end of it until midday Fri. The colder trend in temps
profiles that started yesterday has basically stopped with
basically all snow expected, except perhaps, mixed precip south
of the I-64 corridor in central VA. The axis of highest QPF has
also shifted south somewhat with guidance showing stronger
higher precip building farther south. This appears to be a
moderate to high QPF event with generally 0.5 inches liquid
equivalent across northern MD to an inch south of I-66 in
northern VA. Given the trend of slower onset of precip and
impacts into the area until Wed night and after collaboration
with neighboring offices to the west, it was decided to hold off
of any watches at this time. However, confidence is high this
will be a significant winter precip and long duration event
(36-42 hrs in duration) with moderate impacts. For some areas,
especially outside of the mtns and in southern areas, this will
likely be the largest snow event this season so far.

 

Great news for the DC/BAL corridor. LWX says this will likely be their biggest event of the season so far - inclined to agree here. Hoping you all cash in!

[CAPE]

Latest take from Mount Holly-

Models continue to trend more suppressed and weaker with the southern-stream trough, owing to continued confluent midlevel flow from amplifying troughing in far eastern Canada. As a result, the QPF shield has shifted so that the maximum axis is generally in the southern half of the CWA Wednesday night and Thursday. Large-scale lift will be somewhat weak, so snow rates should be light to modest at best. Nevertheless, temperatures will be sufficiently cold for snow in virtually all of the CWA. By Thursday, current snow totals of 1-3 inches are fairly widespread south of I-78, with the highest amounts generally south of I-76. A second round of snow may occur as a stronger vort max approaches the East Coast on Thursday night and Friday. The NAM has trended well south with this, mostly keeping QPF out of the CWA. The ECMWF has trended this way as well, though to a much less extreme extent. The GFS and CMC, meanwhile, are farther north and provide another round of light snow to much of the area. By Friday, widespread totals of 2 to 5 inches are possible across the area, with highest confidence for the southern half of the CWA. The model trends continue colder for this period as well, given the lingering influence of the surface high to our north. This suggests the event will be primarily snow for the CWA, with any mixing likely to occur in far southern Delmarva and southeast New Jersey. Forecast temperatures were kept lower than consensus, and mainly weighted toward colder raw guidance, which tends to perform best in these regimes. Though the snow will generally be light, the sufficient cold and longer potential duration suggest meaningful impacts appear likely for our forecast area.

[The Ole Bucket]

Sterling a lot more bullish this early morning than it was yesterday..

 

[blueberryfaygo]

The NAM is  4-8 inch event for most with the Jackpot being south of CHO.  

[WinterWxLuvr]

The NAM’s have literally been all over the place

[mappy]

I'm awake. Make better posts. 

[nj2va]

[Jerichohill]

notably the check was in the middle box yesterday, so now they have increased their confidence

[stormtracker]

12 minutes ago, mappy said:

I'm awake. Make better posts. 

I’ll be on Amtrak for the next 3 hours, but even with their shitty wifi, I’ll be here as strong back up with you!  In other words, prepare to moderate alone until that slacker @WxUSAF wakes up. 
 

To make this weather related, noticed the lack of 6z posting. Haven’t looked yet, but that bad huh?

[SomeguyfromTakomaPark]

1 minute ago, stormtracker said:

I’ll be on Amtrak for the next 3 hours, but even with their shitty wifi, I’ll be here as strong back up with you!  In other words, prepare to moderate alone until that slacker @WxUSAF wakes up. 
 

To make this weather related, noticed the lack of 6z posting. Haven’t looked yet, but that bad huh?

GFS and RGEM look on track, NAM misses the second wave. 

[mappy]

2 minutes ago, stormtracker said:

I’ll be on Amtrak for the next 3 hours, but even with their shitty wifi, I’ll be here as strong back up with you!  In other words, prepare to moderate alone until that slacker @WxUSAF wakes up. 
 

To make this weather related, noticed the lack of 6z posting. Haven’t looked yet, but that bad huh?

H2O was up earlier cleaning up the thread, he can help too. safe travels!

GFS looks similar to last night, maybe a little less qpf. NAM was drier. 

[aldie 22]

14 minutes ago, stormtracker said:

I’ll be on Amtrak for the next 3 hours, but even with their shitty wifi, I’ll be here as strong back up with you!  In other words, prepare to moderate alone until that slacker @WxUSAF wakes up. 
 

To make this weather related, noticed the lack of 6z posting. Haven’t looked yet, but that bad huh?

Just using simple addition from the site I look at for JYO 0z gfs had 1.10 liquid and 6z has .82 but 6z now has more for Sunday then 0z had in the form of sn/freezy rain. NAM barely gets JYO to 2" of snow I can look at DCA but I might need help spelling it

ETA 0z DCA .93 liquid 6z .72

[stormtracker]

22 minutes ago, leesburg 04 said:

Just using simple addition from the site I look at for JYO 0z gfs had 1.10 liquid and 6z has .82 but 6z now has more for Sunday then 0z had in the form of sn/freezy rain. NAM barely gets JYO to 2" of snow I can look at DCA but I might need help spelling it

ETA 0z DCA .93 liquid 6z .72

Ah ok. Not as bad as I feared based on lack of postings. 

[North Balti Zen]

3 minutes ago, stormtracker said:

Ah ok. Not as bad as I feared based on lack of postings. 

Maybe people are finally listening and are now afraid to post. This one is a good test of “you want the best snows just south” thesis for the baltimore crew. I would be more comfortable across the DC area. Hope both our areas can score. 

[LP08]

6z euro nudged south compared to 0z.

[aldie 22]

1 minute ago, North Balti Zen said:

Maybe people are finally listening and are now afraid to post. This one is a good test of “you want the best snows just south” thesis for the baltimore crew. I would be more comfortable across the DC area. Hope both our areas can score. 

Seems like 12z needs to make the move North on the euro in some form, the NAM seems a tad lost but who knows. The one thing i'm noticing and I might be wrong of course but nothing is really looking all that cold so as many have been saying we look to be playing with fire with this extended epic period.

[stormtracker]

1 minute ago, LP08 said:

6z euro nudged south compared to 0z.

You got the pretty snowfall maps.  Just curious. 

[aldie 22]

1 minute ago, LP08 said:

6z euro nudged south compared to 0z.

Stubborn model there...GFS probably drops South dramatically at 12z i'd wager

[stormtracker]

1 minute ago, leesburg 04 said:

Seems like 12z needs to make the move North on the euro in some form, the NAM seems a tad lost but who knows. The one thing i'm noticing and I might be wrong of course but nothing is really looking all that cold so as many have been saying we look to be playing with fire with this extended epic period.

I agree for the most part.  I mean obviously for my back yard south isn’t bad. But i really believe this is where we want ii for what is probably The inevitable tick north.  But of course now that we want a slight tick north we won’t get it.  

[mattie g]

One thing that stood out to me with the 00z Euro is that the northern edge of the QPF field has really been eaten away the last couple runs, with northern MD now running from 0.3-0.5" total for the duration, with similar decreases down to just about a line from Alexandra/Warrenton. The area south of that has remained pretty steady, so to me it seems the goalposts are beginning to narrow on keeping the most moisture in central VA. We have time, but I'm not sure we'll see any huge adjustments, though even just a 20-mile shift in that northern edge will make a huge difference for a lot of folks.

Edit: The 6z euro map shows exactly what I was talking about. Northern edge is getting gobbled up.

[aldie 22]

1 minute ago, stormtracker said:

I agree for the most part.  I mean obviously for my back yard south isn’t bad. But i really believe this is where we want ii for what is probably The inevitable tick north.  But of course now that we want a slight tick north we won’t get it.  

I've never been one to care about getting the highest totals for any storm, not my style....I just want to be invited to the party to hold up a wall and look at everyone else having fun. Maybe this is the one that gets DC and the Southern burbs more in line with the rest of the region. I mean what really is the big deal between 4" and 6"?

[CAPE]

Just now, mattie g said:

On thing that stood out to me with the 00z Euro is that the northern edge of the QPF field has really been eaten away the last couple runs, with northern MD now running from 0.3-0.5" total for the duration, with similar decreases down to just about a line from Alexandra/Warrenton. The area south of that has remained pretty steady, so to me it seems the goalposts are beginning to narrow on keeping the most moisture in central VA. We have time, but I'm not sure we'll see any huge adjustments, though even just a 20-mile shift in that northern edge will make a huge difference for a lot of folks.

The confluence/HP to the north is a tad problematic on recent runs, especially as the wave moves further east. Drier air is eating away at the precip  just to the NE. Need that to be an issue up in eastern PA and NJ, not here.

[LP08]

11 minutes ago, stormtracker said:

You got the pretty snowfall maps.  Just curious. 

 

[stormtracker]

3 minutes ago, leesburg 04 said:

I've never been one to care about getting the highest totals for any storm, not my style....I just want to be invited to the party to hold up a wall and look at everyone else having fun. Maybe this is the one that gets DC and the Southern burbs more in line with the rest of the region. I mean what really is the big deal between 4" and 6"?

Oh, I’m with you on that. I’m def not a size king. I could care less about getting the most, just put me in the game. I don’t care if FDK gets 18” and i get like 12. Like i said. I just wanna be at the party. 

[frd]

5 minutes ago, CAPE said:

The confluence/HP to the north is a tad problematic on recent runs, especially as the wave moves further east. Drier air is eating away at the precip  just to the NE. Need that to be an issue up in eastern PA and NJ, not here.

This is rather pathetic .

This is looking like a non event here 

 

 

[WxUSAF]

I’ve only taken a quick look this morning, but seems the euro paints max precip amounts just a bit south of where the gfs+GGEM/RGEM do (just south of DC vs near BWI) for wave 1. Wave 2 looks more similar across guidance. Shift the euro north by like 20-30mi for wave 1 and you’d see pretty good consensus.

[Interstate]

1 minute ago, WxUSAF said:

I’ve only taken a quick look this morning, but seems the euro paints max precip amounts just a bit south of where the gfs+GGEM/RGEM do (just south of DC vs near BWI) for wave 1. Wave 2 looks more similar across guidance. Shift the euro north by like 20-30mi for wave 1 and you’d see pretty good consensus.

This is looking like a Jan 2019 repeat

[CAPE]

5 minutes ago, frd said:

This is rather pathetic .

This is looking like a non event here 

 

 

I think Mount Holly nailed it as usual. The initial wave is  weak/weakening as it moves east. They are thinking 1-3 here. The second wave is a bit more juiced, but the trends are further south with that. Need a couple ticks north in the next few model cycles.

[WinterWxLuvr]

8 minutes ago, LP08 said:

 

That map is just silly for my area. Not seeing me getting nearly 10” of snow on about 0.6 precip

[CAPE]

I will gladly risk getting some sleet, vs all snow and pathetically light accumulations.