February 19-21, 2019 storm threat

[Danajames]

Per NWS discussion/Saturday morning:  

Canadian high pressure residing over the Upper Midwest will migrate
eastward during the day on Tuesday, building to our north through
Tuesday evening. This will deliver dry conditions and slightly below
normal temperatures under a light northerly flow. At the same time,
an upper trough will be lifting out of the southwestern states,
aiding in the development of an area of low pressure near the lower
Mississippi Valley. This low will strengthen and gather ample
moisture from the Gulf as it tracks northeastward into Tuesday
night. Clouds will be on the increase Tuesday afternoon and evening,
but dry conditions are expected to prevail through midnight. After
which, precipitation will spread northward into the region, and with
the high situated to our north, cold air will be funneled and locked
in across our area. A rain/snow mix will be possible across the
southern half of the CWA predawn Wednesday, with snow the favored
across the north given colder temperatures at the surface and aloft.

As the system progresses northward during the day on Wednesday, warm
air advection will be increasing aloft, as 850 temps likely rising
above freezing by Wednesday evening for much of the area. This will
bring a transition to a wintry mix throughout the day across the
area as low level cold air hangs on for portions of the area. It is
still too early to discern exact ptype and timing, but one thing is
becoming more and more clear is the plentiful moisture associated
with this system. QPF will likely approach or exceed an inch for a
bulk of the area through Wednesday night. Depending on the strength
and stubbornness of the cold air at the surface, those
climatologically favored locations near and west of the Blue Ridge
could see an extended period of wintry precipitation Wednesday and
Wednesday night.

By Thursday morning, low pressure off the Mid Atlantic coast will be
pushing northeastward into the Atlantic as high pressure nudges into
the region from the west. This should bring an end to precipitation
by Thursday afternoon, and with continued warming temperatures at
the surface and aloft, rain will be favored across the CWA Thursday
morning. High pressure to the north will deliver mostly dry
conditions into Thursday night, before another area of low pressure
approaches from the Tennessee Valley late Friday and Friday night.
Wintry precipitation will be possible for portions of the area
Friday night.

[Danajames]

Not sure if the other thread covers mid-week but started this anyway. 

[snowfan]

Way too early for this

[nj2va]

56 minutes ago, losetoa6 said:

Just a quick glance but the cad wedge looks better on the 6z Gefs . And we're still in the game at 100 hours out . Look forward to 12z 

Actually looking closer Cad looks similar to 0z 

Wpc at 96 looks to favor a primary going into west/ central Tennessee 

 

That’s not a bad look there at all. It would be great if we can get that primary into eastern TN at that time to throw the precip into the cold quicker. At this point I’m rooting for hot and heavy WWA given the CAD. “Easier” to score than trying to win a coastal redevelopment battle for our latitude. 

[MD Snow]

6z euro? 

[Joshfsu123]

My bar for this storm is 3 inches. I know yesterday the models were producing huge numbers but that was a perfect set-up... this is a tough forecast but what it does have is the early thump. But hoping to see the GFS get back on board with the other models. ICON improved at 06z slightly, from 00z, and the EURO/UKMet/FV3 still looks solid. Gonna be a few more days before we know truly how strong the CAD will be. As @stormtracker said yesterday, which has been forgotten by many, yesterday was probably the high bar for many of the models, in terms of snow output.

[nj2va]

3 minutes ago, MD Snow said:

6z euro? 

6z and 18z only run to hour 90. 

[CAPE]

55 minutes ago, Joshfsu123 said:

My bar for this storm is 3 inches. I know yesterday the models were producing huge numbers but that was a perfect set-up... this is a tough forecast but what it does have is the early thump. But hoping to see the GFS get back on board with the other models. ICON improved at 06z slightly, from 00z, and the EURO/UKMet/FV3 still looks solid. Gonna be a few more days before we know truly how strong the CAD will be. As @stormtracker said yesterday, which has been forgotten by many, yesterday was probably the high bar for many of the models, in terms of snow output.

I have no bar. I don't see the point. Sure I would like to see 3-4", but if it ends up another 1/2" that gets washed away by a deluge, better than nothing. This winter is clearly in dud territory for my location, so I am beyond being picky.

[MillvilleWx]

13 minutes ago, losetoa6 said:

Eps continues to get colder at the surface for Wednesday picking up more on the wedge potential. 

EPS Max highs for Wed/

IAD - 33

BWI - 34

CARROLL - 31

 

I'm actually a little concerned for ice in this setup. Initial WAA snows, but then a flip to ice quicker than normal is possible given the climo trends with these types of systems. Something to watch. Of course, a massive snow thump to ice is on the table, but I'd remain cautious with this type of evolution. 

[WxUSAF]

18 minutes ago, losetoa6 said:

Eps continues to get colder at the surface for Wednesday picking up more on the wedge potential. 

EPS Max highs for Wed/

IAD - 33

BWI - 34

CARROLL - 31

 

Is that high temp of the mean or the warmest ensemble member?

[Joshfsu123]

17 minutes ago, C.A.P.E. said:

I have no bar. I don't see the point. Sure I would like to see 3-4", but if it ends up another 1/2" that gets washed away by a deluge, better than nothing. This winter is clearly in dud territory for my location, so I am beyond being picky.

Same truthfully. I'm moving to Florida in early March, so this will likely be my final snow system/storm in DC ... as long as it snows, could care less how much. Gonna miss it. 

[nj2va]

FWIW EPS snowfall probabilities for DC:

>1” 86%

>3” 70%

>6” 33%

 

[Stormpc]

2 minutes ago, Joshfsu123 said:

Same truthfully. I'm moving to Florida in early March, so this will likely be my final snow system/storm in DC ... as long as it snows, could care less how much. Gonna miss it. 

Same here. Permanent move to Northern OBX in May so my time is running short. 

Hopefully the waa gets here Tuesday night. Todays poof was a little disappointing.  

[BlizzardNole]

23 minutes ago, Joshfsu123 said:

Same truthfully. I'm moving to Florida in early March, so this will likely be my final snow system/storm in DC ... as long as it snows, could care less how much. Gonna miss it. 

Josh!  Where in FL are you moving?  Were you here long enough to see some of our great winters?

I am hoping for a nice front-end thump with next week's set-up, but man ice could be  concern for some.  One Damascus guy I know lost power for 10 hours in that last deal.

 

[BristowWx]

26 minutes ago, Stormpc said:

Same here. Permanent move to Northern OBX in May so my time is running short. 

Hopefully the waa gets here Tuesday night. Todays poof was a little disappointing.  

Well at least you won’t have to worry about p-type very often.  OBX is a nice way of life.  All the best on the move.  

[BaltimoreWxGuy]

NAM looking juicy at 84...should be pretty much in range by tomorrow morning

[stormtracker]

NAM looks pretty good. But NAM.  high is moving into position. We should see where it’s going by 0z

[Steve25]

I guess I'm going to be the Debbie downer when it comes to this storm. I just hate the track way west like this. My expectations based on this setup with no extreme cold out ahead of it and that track is a quick burst of snow and ice late Tuesday night, accumulations similar to last week's event, then rain. Hopefully this storm does much better than that and you can all get after me. I just feel like that's what the pattern and setup favor. 

[SnowGolfBro]

1 minute ago, stormtracker said:

NAM looks pretty good. But NAM.  high is moving into position. We should see where it’s going by 0z

NAM extrapolation says to me we are in the game!

[BaltimoreWxGuy]

3 minutes ago, Steve25 said:

I guess I'm going to be the Debbie downer when it comes to this storm. I just hate the track way west like this. My expectations based on this setup with no extreme cold out ahead of it and that track is a quick burst of snow and ice late Tuesday night, accumulations similar to last week's event, then rain. Hopefully this storm does much better than that and you can all get after me. I just feel like that's what the pattern and setup favor. 

I wouldn’t be shocked if that happened but, the track of this one is a little better...didn’t that one pretty much go all the way up to Wisconsin?

[Grothar of Herndon]

1 minute ago, BaltimoreWxGuy said:

I wouldn’t be shocked if that happened but, the track of this one is a little better...didn’t that one pretty much go all the way up to Wisconsin?

Yes, this one is different. There is going to be rain next week after this storm so no need to Deb especially in this thread. What we need is for a massive thump to enjoy.

[LP08]

ICON sped up by a few hours.  Nice thump again.

[eurojosh]

I'm counting on this storm. Thinking about taking Tues-Thurs off and heading either to Blue Knob (CAD) or Timberline (Coastal) or not and going to fing work (cutter).

[LP08]

One issue though with the icon is that the primary is further west and hangs on far to long so it’s a few hours of snow then over to mix and then deluge.

[Grothar of Herndon]

2 minutes ago, LP08 said:

One issue though with the icon is that the primary is further west and hangs on far to long so it’s a few hours of snow then over to mix and then deluge.

When you said sped up was hoping more east. Would be great to get the transfer and coastal. Oh well let see what the rest of the 12z models show.

[MillvilleWx]

4 minutes ago, LP08 said:

One issue though with the icon is that the primary is further west and hangs on far to long so it’s a few hours of snow then over to mix and then deluge.

I think the ICON is a terrible model, but verbatim, it's a thump to ice NW of the fall line. DC on south is a cold rain after a quick mix transition. Surface never goes above freezing for quite a few. Thank god it's the ICON though. 

[LP08]

Just now, Grothar of Herndon said:

When you said sped up was hoping more east. Would be great to get the transfer and coastal. Oh well let see what the rest of the 12z models show.

Yeah should have clarified that precip was a touch quicker.  I think (famous last words) that the high end for us closer to DC is 1–4 then mix then rain.  Haven’t seen a lot a progress in getting the primary to transfer quicker for the high end solutions.

[psuhoffman]

37 minutes ago, stormtracker said:

NAM looks pretty good. But NAM.  high is moving into position. We should see where it’s going by 0z

We ignored the NAM when it had almost no wave today... lol. 

Here is the rub with the NAM. It often just adds noise (even at short leads) because it’s prone to go off on wild tangents and you never know if it’s picking up on the right idea or not. 

But when it does have the right idea it often does the best job with the details. Seeing CAD. Getting the details of the thermal profile. Meso scale banding. If it has the right general synoptic setup it often has the best depiction of details. So there are times it scores the coup like Jan 2016 with the heavy snow into NYC or picking up on the waa thump in November this year or seeing the weird inverted trough aided ccb with the January storm. Problem is you can’t tell when it’s scoring the coup or just standing on some soap box spewing crazy talk.  

[CAPE]

2 minutes ago, MillvilleWx said:

I think the ICON is a terrible model, but verbatim, it's a thump to ice NW of the fall line. DC on south is a cold rain after a quick mix transition. Surface never goes above freezing for quite a few. Thank god it's the ICON though. 

Not a big fan of the ICON for here this run. Not ICONIC.

[LP08]

2 minutes ago, MillvilleWx said:

I think the ICON is a terrible model, but verbatim, it's a thump to ice NW of the fall line. DC on south is a cold rain after a quick mix transition. Surface never goes above freezing for quite a few. Thank god it's the ICON though. 

I think it does ok with track and placement but it’s surface temps usually run cold.  I think the reason it gets so much run is that it comes out during dead times before the big guns.