December 16/17 Winter Event

[CAPE]

1 minute ago, leesburg 04 said:

Euro looks good to me, i'm guessing it is the not preferred model these days?

Preference depends on location. 

Not a bad look for Leesburg! Or Carroll county.

[psuhoffman]

@high risk

The NAM does sometimes sniff stuff out.  It nailed the sleet fest coming from range in March 2017 when all the globals had snow.  But the problem is, its wildly inconsistent at range...which is to be expected for a model designed to handle convection and meso scale banding.  It is useful in showing thermals better and a better detailed representation of what the storm might look like...but wrt synoptic level general things like track, at range it's hard to take any one run seriously because you don't know what it is onto something or when it is just on something.  

@BTRWx's Thanks Giving

You NEED to stop with those crap snow depth maps.  I have no idea how they are calculated but over the years they have been just as garbage as the weenie weatherbell ones.  They end up seeming right for the same reason some of the trolls here do...because we fails so often.  The models are often wrong and thigns shift worse.  And when that happens...it makes a map like those look good.  But whenever a storm actually does what the guidance says...those bust low.  WAY LOW.  I will give you one example just because I looked at the soundings.  The NAM one you posted shows Westminster with 3" of positive snow depth.  But they get about an inch of QPF with all levels at or below freezing.  They get another .8 of QPF that is obviously sleet from the sounding.  The surface is below freezing the whole time.  Heck even if the whole storm was sleet that would be more than 3"!!!  That is just crazy stupid.  Now maybe the storm shifts even further NW and then 3" in Westminster isn't a bad idea.  If the track actually penetrates inside the mouth of the Potomac...that would be trouble for up here...but a track like that NAM had over the southern Bay in up the eastern Delmarva supports a big snow (with some mixing yes) up here...and the model shows that if you look at the actual soundings and hour by hour plots...then that depth map shows something completely different.  THis is not the only time but its a current example of how that map is just WRONG.  

 

[SomeguyfromTakomaPark]

4 minutes ago, baltosquid said:

So close on those 850's. Just a small tick or so, but the models aren't budging.

Euro says we’re still in the game in the metros.  Gonna be close but not ready to wave the white flag yet. 

[PhineasC]

If zwyts isn’t here you know the models look like shit for DC. If Ian shows up, a HECS is imminent. 

[clskinsfan]

5 minutes ago, losetoa6 said:

Impressive qpf modeled up to game time . 2--2.20" ...sweet

Yeah. I actually expected it to back down some from the 12Z run. But this run is even better for us. Crazy. 

[osfan24]

4 minutes ago, baltosquid said:

So close on those 850's. Just a small tick or so, but the models aren't budging.

Yeah, it's agonizingly close.

[PivotPoint]

1 minute ago, LP08 said:

Adding the surface which looks above freezing in and around dc for the duration.

Man look at those 70s off the coast of Carolina. I have a feeling this thing is going to be juiced at the very least. Whoever keeps temps is going to get a qpf walloping 

[WxUSAF]

1 minute ago, LP08 said:

Adding the surface which looks above freezing in and around dc for the duration.

 

 

Without seeing a sounding, I can't be sure, but that seems a lot like the 18z GFS for the R/S line area.  Nearly isothermal profile right around freezing from ~850mb to the surface.  Very tiny margin between hours of heavy wet snow and driving rain.  

[mappy]

1 minute ago, PhineasC said:

If zwyts isn’t here you know the models look like shit for DC. If Ian shows up, a HECS is imminent. 

I could probably get Ian to stop by and fill in that bingo card spot lol

[WxUSAF]

1 minute ago, losetoa6 said:

18z still keeps N.Carroll all frozen through the duration.  Deform looks more impressive.  Mixing is a certainty even here but with big qpf ...big totals still possible 

Can you post some 3hrly surface maps with precip?

[osfan24]

Seemed like a step back with thermals from 12z, but it's just 10 miles here or 10 miles there making the difference it seems.

[LP08]

Just now, WxUSAF said:

Without seeing a sounding, I can't be sure, but that seems a lot like the 18z GFS for the R/S line area.  Nearly isothermal profile right around freezing from ~850mb to the surface.  Very tiny margin between hours of heavy wet snow and driving rain.  

My goal in mby is to hopefully avoid a driving rainstorm after a few hours of snow.  Hopefully during lulls we can hold on to 33-35 and stay “frozen” for most of the storm.  

[Weather Will]

If the low does go due north up the Bay that is too close for comfort.  20- 30 miles east would make a big difference.  May be an hour by hour outcast Late Wed. Afternoon/evening.  We are only 48 hours out, but we are still 48 hours out....another 30 miles west track no one will be happy east of the Blue Ridge or in Northern MD.  

2020 has proven anything is possible.

[PhineasC]

3 minutes ago, WxUSAF said:

Can you post some 3hrly surface maps with precip?

He’s an electrician not a met. LOL

[mattie g]

12 minutes ago, poolz1 said:

Agreed...I flirt with sleet but the backend in a better position (insert joke) to linger and add up.

I thought that said “to finger.”

[WxUSAF]

3 minutes ago, LP08 said:

My goal in mby is to hopefully avoid a driving rainstorm after a few hours of snow.  Hopefully during lulls we can hold on to 33-35 and stay “frozen” for most of the storm.  

Yeah, I was thinking sleet, but 18z GFS and Euro seem more like snow vs. rain.  

These are really tiny thermal details.  I'm pretty much just in "chips fall" time.  Seems like we know the basic deal here. 

[LP08]

4 minutes ago, WxUSAF said:

Can you post some 3hrly surface maps with precip?

 

[clskinsfan]

It almost looks like it pivots as it starts to pull away. These qpf numbers out of the Euro are right up there with all of our biggest storms. About 36 hours from onset ya'll.

[H2O]

1 minute ago, losetoa6 said:

3hr precip 

 

My phone is slowww

If that 540 does what it shows I might see it end as snow with those rates

[WxUSAF]

That backside CCB does look nice on the 18z euro.  Hope it happens.  

[SomeguyfromTakomaPark]

4 minutes ago, losetoa6 said:

3hr precip 

 

 

My phone is slowww

That’s really actually pretty to look at.  I know we shouldn’t count on back end snows and all, but it’s nice to think about!

[PhineasC]

@Jmister looks like a good storm for you man!

[caviman2201]

Doesn't the progression of the low look a little odd? At hr54 its at the CBBT, hr55 its 10mi offshore, hr56 its off the southern tip of Chincoteague (all fine so far) but then at hr57 it jumps 25mi NW over Deale, MD, moves due N over Cambridge and then moves NE from there.  Hr53-54 on 18z was significantly SE of Hr59-60 on the 12z before that random jump NW where it 'corrected' to match 12z's SLP track.

[Jmister]

Just now, PhineasC said:

@Jmister looks like a good storm for you man!

Hoping so! I keep following this sub-forum closest because if the models are good for you guys, it's good news for me in the PHL area haha.

Lots of good entertainment here too.

[Chris78]

Just now, clskinsfan said:

It almost looks like it pivots as it starts to pull away. These qpf numbers out of the Euro are right up there with all of our biggest storms. About 36 hours from onset ya'll.

Man we really flirt with sleet all the way out to I 81.

But if the Euro is right and we end up with over 2 inches of qpf in the form of snow it will be historic along the I - 81 corridor.

[osfan24]

3 minutes ago, caviman2201 said:

Doesn't the progression of the low look a little odd? At hr54 its at the CBBT, hr55 its 10mi offshore, hr56 its off the southern tip of Chincoteague (all fine so far) but then at hr57 it jumps 25mi NW over Deale, MD, moves due N over Cambridge and then moves NE from there.  Hr53-54 on 18z was significantly SE of Hr59-60 on the 12z before that random jump NW where it 'corrected' to match 12z's SLP track.

I thought it was odd as well. There's also the double barrel structure going on as well, though it seems the low closest to the coast is the dominant player.

[PhineasC]

4 minutes ago, Jmister said:

Hoping so! I keep following this sub-forum closest because if the models are good for you guys, it's good news for me in the PHL area haha.

Lots of good entertainment here too.

Can’t you hook @WxUSAF up with some better model data? NASA or wherever he works doesn’t have the good stuff apparently. LOL

[caviman2201]

3 minutes ago, osfan24 said:

I thought it was odd as well. There's also the double barrel structure going on as well, though it seems the low closest to the coast is the dominant player.

If it had continued NE from Hr53-56, it would have been a significant move SE from 12z... maybe thats what the SLP will actually do, but maybe its something someone smarter than me can explain because 12z didn't do that.  It was tucked the whole way up the coast and move more or less due NE.

[clskinsfan]

5 minutes ago, Chris78 said:

Man we really flirt with sleet all the way out to I 81.

But if the Euro is right and we end up with over 2 inches of qpf in the form of snow it will be historic along the I - 81 corridor.

But that is the game you have to play for the heaviest precip. Ride the sleet/Snow line and stay all snow and you are getting hammered. 

[BristowWx]

5 minutes ago, PhineasC said:

Can’t you hook @WxUSAF up with some better model data? NASA or wherever he works doesn’t have the good stuff apparently. LOL

Where are you for this event?  NH, MD or DE?