Jan 31 - Feb 1 Event - STORM MODE THREAD

[psuhoffman]

2 minutes ago, anotherman said:

Is there a sharp northern cutoff?

Not as bad as on the RGEM/GGEM.  My area kind of is in a screw zone of subsidence between bands but that is not something I am going to worry about at this range...and we all know that if the southern PA/northern MD area gets into the actual CCB good banding will set up here due to oragraphic influences.  Mappy's area gets absolutely crushed with one of those bands but the UK has some weird dry pockets mixed in that screw over some areas (me) lol.  Even if that were true it wont nail that from this range.  

[Its a Breeze]

8 minutes ago, SnowenOutThere said:

Which model is the NWS relying on because I don't really understand why it has a significant ice storm for the area. From my understanding the only models that really are behind this are the Nam models. I just don't really understand why it has this, the GFS just has a switch to rain and back to snow. The Euro is snow and so are a bunch of other models. Am I just not understanding something?

Looks like we're also still 'orange' for a winter storm threat. Can we at least get red? lol

I think it's a better safe than sorry-just in case type deal. Throw in everything when there's still some uncertainty....

[Hypothetical 240 hour snow]

I just want the Euro to stop the suppression trend it has had for like the last 24 hours... even if it doesn't come in line with the better captures depicted by the other guidance, if it at least stabilizes near where it was, it would at least make the lower end cut-off a little clearer for this event. Because if it keeps trending more suppressed the floor on this event would be pretty low for anyone NW of I-95 (and maybe even near I-95, depending on how certain we think the initial WAA thump will be given the transfer in progress and the antecedent dry airmass).

[MD Snow]

2 minutes ago, Its a Breeze said:

Looks like we're also still 'orange' for a winter storm threat. Can we at least get red? lol

I think it's a better safe than sorry-just in case type deal. Throw in everything when there's still some uncertainty....

I'd imagine watches will go up with the afternoon update this afternoon. Tomorrow morning at the latest. 

On a side note...All it took was @psuhoffman having a mini melt last night for things to start heading in the right direction again! haha!

[Hypothetical 240 hour snow]

Just now, MD Snow said:

I'd imagine watches will go up with the afternoon update this afternoon. Tomorrow morning at the latest. 

Given that the event-start is within 48 hours I see no way watches don't go up with the afternoon package, probably for all CWAs of interest in this sub. Yeah there is certainly some potential for only advisory amounts if the suppressed solutions verify and the CCB misses SE but converting watches to advisories is perfectly fine for the NWS.

[Heisy]

We get a reasonable euro run today I think it’s game on, but this hobby is NEVER that easy. So I don’t expect that to happen. Maybe a slight tick NW? 

[psuhoffman]

Just now, MillvilleWx said:

The evolution was perfect for I-95. It's likely underdone too in the intensity department given the dynamics and strength of the 85H and 7H lows. The placement was great though. A good sign 

would you agree that if we do get a more tucked capture stall like the GGEM/UK we also likely get the typical NW deform band that guidance almost always misses with amplifying mid atlantic coastal systems.  Seems to me, and please correct me if I am wrong, that guidance from range tends to focus the deform band along the best fgen associated with the moisture transport from the coastal where it intersects the CCB and the instability from the upper low.  And there will be a band there...but what it often misses is the increased forcing along the NW fringe of the CCB where the moisture transport hits the "brick wall" of confluence to the north.  That resistance typically seems to add lift and while its not to the degree as further south you also tend to get really high ratios there.   IMO those 2 factors contribute to that deathband we often see that guidance totally misses on the northern fringes of the CCB.

[psuhoffman]

3 minutes ago, MD Snow said:

I'd imagine watches will go up with the afternoon update this afternoon. Tomorrow morning at the latest. 

On a side note...All it took was @psuhoffman having a mini melt last night for things to start heading in the right direction again! haha!

I thought I controlled myself pretty well considering what they run did to me...I made like 3 posts after the euro then went to bed.  lol.  I still like where we stand, especially 95, I just don't like the introduction of that feature in New ENgland adding uncertainty.  Uncertainty sometimes doesn't work out the way we want and damnit I want this snow curse broken NOW. 

[MillvilleWx]

3 minutes ago, psuhoffman said:

would you agree that if we do get a more tucked capture stall like the GGEM/UK we also likely get the typical NW deform band that guidance almost always misses with amplifying mid atlantic coastal systems.  Seems to me, and please correct me if I am wrong, that guidance from range tends to focus the deform band along the best fgen associated with the moisture transport from the coastal where it intersects the CCB and the instability from the upper low.  And there will be a band there...but what it often misses is the increased forcing along the NW fringe of the CCB where the moisture transport hits the "brick wall" of confluence to the north.  That resistance typically seems to add lift and while its not to the degree as further south you also tend to get really high ratios there.   IMO those 2 factors contribute to that deathband we often see that guidance totally misses on the northern fringes of the CCB.

Oh absolutely. This is a given with history on the side to back it up. There was a convergent area to the NW during the 2016 storm that slammed parts of PA while the deformation axis raked the 81 corridor. I think it's a 700-500mb frontogen that causes it, and that is some high ratio fluff too. Not as dramatic in total rates compared to the 700mb frontogen/deformation axis, but it will pile up quickly. That will not be situated until the 11th hour. 

[SomeguyfromTakomaPark]

5 minutes ago, Wentzadelphia said:

We get a reasonable euro run today I think it’s game on, but this hobby is NEVER that easy. So I don’t expect that to happen. Maybe a slight tick NW? 

It's already game on.  Pretty much every piece of guidance targets our region for accumulating snow, and most of them give us a warning level event.  We're now well inside of 100 hours.  Of course every piece of guidance could take a historically bad dump and we all end up smoking cirrus but that doesn't seem likely.  

[mappy]

As a reminder, since we do this every.damn.storm. It does not matter when watches will go up, or who will get an advisory, or who will get a warning. It's going to snow regardless of when they do it, so lets not beat that horse until its a bloody pulp. 

[BigCountry]

Is this the type of potential storm where those of us N-NE of DC (Mitchellville/Bowie, MD area) could possible get more snow than the usual areas? When some people complain "it's moving east", is this something that those a little East of DC want? Or tomatos-tomatoes?

[SnowGolfBro]

1 minute ago, DCTeacherman said:

It's already game on.  Pretty much every piece of guidance targets our region for accumulating snow, and most of them give us a warning level event.  We're now well inside of 100 hours.  Of course every piece of guidance could take a historically bad dump and we all end up smoking cirrus but that doesn't seem likely.  

We are really only 36 hours from the WAA piece of the storm. Radar hallucinations start tomorrow afternoon.  Need that trough to get a neutral tilt for part 2 and it’s game on

[IUsedToHateCold]

Just now, BigCountry said:

Is this the type of potential storm where those of us N-NE of DC (Mitchellville/Bowie, MD area) could possible get more snow than the usual areas? When some people complain "it's moving east", is this something that those a little East of DC want? Or tomatos-tomatoes?

I wouldn’t count on it. Deformation bands tend to set up to our north west in most coastal storms. That said, it can happen. I’d lock up the 12z CMC in a heartbeat, but it’s probably wrong. 

[Maestrobjwa]

5 minutes ago, DCTeacherman said:

It's already game on.  Pretty much every piece of guidance targets our region for accumulating snow, and most of them give us a warning level event.  We're now well inside of 100 hours.  Of course every piece of guidance could take a historically bad dump and we all end up smoking cirrus but that doesn't seem likely.  

I've always thought of this in two parts: WAA snowfall more certain, coastal a wild card. The only big bust scenario is to get nothing from either...and hopefully that is less likely.

[SnowDreamer]

22 minutes ago, Baltimorewx said:

I know they may not be as useful anymore but can anyone shed light on if the GEFS generally supports the OP? Didnt see a post

Yes, but at this range I'd be really concerned for the GFS if it didn't 

 

[BTRWx's Thanks Giving]

I just hope the GFS isn't lagging on the euro's prior trends of bombing the coastal.

[WxUSAF]

CWG, with input from @usedtobe, going with 4-8” total for DC as their opening bid. 2-4” from WAA, 2-4” after. Second part less certain obvs.

[clskinsfan]

29 minutes ago, psuhoffman said:

UK is a picture perfect capture/stall location for our area.  Hopefully the euro follows.  

CCB's DC/Nova for 24 hours straight. Gorgeous. 

[snowmagnet]

2 minutes ago, IUsedToHateCold said:

I wouldn’t count on it. Deformation bands tend to set up to our north west in most coastal storms. That said, it can happen. I’d lock up the 12z CMC in a heartbeat, but it’s probably wrong. 

Fairfax Co and Loudoun Co tend to do well with the deform bands, but I guess it just depends on the placement of the Low.  I remember several storms in the past decade where we we got pounded with much higher numbers than forecasted.  

[anotherman]

1 minute ago, BTRWx's Thanks Giving said:

I just hope the GFS isn't lagging on the euro's prior trends of bombing the coastal.

I thought the same thing.  It just seems like it's always a day behind.  Or several days.

[jaydreb]

Just now, WxUSAF said:

CWG, with input from @usedtobe, going with 4-8” total for DC as their opening bid. 2-4” from WAA, 2-4” after. Second part less certain obvs.

Seems reasonable IMO.  Glad to see Wes on board.  

[LP08]

Didn't see the CMC Kuchera map, for posterity of a true beat down.

[BigCountry]

Just now, WxUSAF said:

CWG, with input from @usedtobe, going with 4-8” total for DC as their opening bid. 2-4” from WAA, 2-4” after. Second part less certain obvs.

I'm definitely not any level close to the rest of you, but that seems fairly low at this point. My initial thoughts right now are more in the 6-10" range.

[WxUSAF]

1 minute ago, BigCountry said:

I'm definitely not any level close to the rest of you, but that seems fairly low at this point. My initial thoughts right now are more in the 6-10" range.

Difference between forecasting for the city and the 'burbs.  Pending the euro, I'm probably going to tell my friends+family 5-10" or 6-12", with more upside than downside risk.  But they all almost uniformly live in the 'burbs.  I think 4-8" for DC is a very reasonable forecast at this point.  If this sort of GFS+GGEM+Ukie blend forecast holds through tomorrow's 12z runs, then you can bump that up.  

[Kmlwx]

2 minutes ago, BigCountry said:

I'm definitely not any level close to the rest of you, but that seems fairly low at this point. My initial thoughts right now are more in the 6-10" range.

I'd say that's VERY reasonable. Better to start low and increase with confidence as you get closer. If the CCB fails, 6-10" will be a tall task to hit for widespread areas. Going from 6-10" downwards is a bad look. Remember that CWG is geared towards lay people and not us weenies on a weather forum. 

They are operating under a different approach than pure weenies. 

[SnowDreamer]

2 minutes ago, BigCountry said:

I'm definitely not any level close to the rest of you, but that seems fairly low at this point. My initial thoughts right now are more in the 6-10" range.

You'll find that many reputable meteorologists (read: not DT) forecast notably below the snow total maps we post here. And FWIW, they have a good reason to do so. 

CWG is also more conservative than many

[AmericanWxFreak]

[WEATHER53]

Gotta ask about the low being 150-200 miles east of OC and then getting pushed west for 12+ hours? I know there is a high to east of ocean low but still; that projection is rare and I don’t rememer  something like that having occurred before?

[stormtracker]

1 hour ago, Hypothetical 240 hour snow said:

Yeah so I guess the consensus is the CMC can't be trusted unfortunately, the EC solution where the band sets up further SE seems more plausible.

Where is that consensus.  Give us a link or reference.