Feb Long Range Discussion (Day 3 and beyond) - MERGED

[osfan24]

13 minutes ago, HighStakes said:

All these storms when we have blocking and now there becoming quick hitters. Where's the log jam?

Yeah, I'm also perplexed by why storms are zipping in and out so quickly. Also super frustrating to see we can't get one of these storms coming out of the gulf to wind up. The temps are fine. How hard is it? Everything is either north and a mixed bag here or sheared out and we get some crumbs if we are lucky.

[WxUSAF]

GGEM is mostly snow for Tuesday FWIW.  Looks like the Icon. 

[psurulz]

I honestly don't understand how these storms are zooming through with all the blocking.  I thought blocking was supposed to cause a log jam of storms.  Is it something to do with the spacing of each storm that's messing things up for us?

[StormchaserChuck!]

Now, a typical rule is, we get ice storms in -EPO -WPO, but not -PNA. -PNA can sometimes ice, but it underperforms. Models have a slight +EPO and +WPO and the -PNA ridge is all the way SE off the west coast.. I'd bet against anything big. 

[WinterWxLuvr]

4 minutes ago, psurulz said:

I honestly don't understand how these storms are zooming through with all the blocking.  I thought blocking was supposed to cause a log jam of storms.  Is it something to do with the spacing of each storm that's messing things up for us?

They aren’t storms for the most part. Measly little 1012 lows aren’t what I’d call storms

[psuhoffman]

3 hours ago, real said:

Yea, but even among those 5 events, the only one that would really been that big of storm, if i recall correctly, is the two-day Miller B two weeks ago that hit NYC. Ji has been correct. Most things seem to have also trended drier, faster, etc, as they have approached this region this winter.   And many of these events were not even that close to stay all-snow, despite what the models suggested was possible a few days ahead of time. . I could live with missing a storm because you live in the city and the snow/rain line sets up in Fairfax... But most of these storms have been an all-encompassing screw job for the entire close-in DC region, and it all just seems to fall apart on approach. 

But there was no HECS storm in 2015 or 2014 and those were considered good winters.  You are right...there wouldn't have been a HECS storm this year so far in DC regardless of the temp issues but let me make a point by playing an "alternate universe" where its 2C colder from 700mb on down in DC.  I think this is a fair temp to assume may have changed in the last 20 years due to a combo of AGW, UHI, and simply the current on fire base states of the Pacific and Atlantic oceans!

 I am going through every storm where if you subtract 2C from the column h7 to the surface and exactly what that would have meant to the result in DC proper (not necessarily National airport in that lava pit they take measurements at).  So storms where that would have got the surface down to a supportive temp for snow (say 33-34) and gotten the column above that below freezing.  I am going to be conservative but fair.

Dec 14th DC recorded 1.06 from a wave.  Not all of that would have been frozen...it was a cold boundary sinking south.  I got about 3" up here but the best moisture actually was suppressed SOUTH of me.  Problem was even with a perfect wave track the boundary layer was scorched in the coastal plain.  It was upper 30's rain.  You subtract 2C from that and it ended as 2-4" of snow. 

Dec 16th DC recorded 1.11 QPF.  Not all of that would have been snow if you subtract 2C... eventually the warm mid level would have won out...but at least 5-7" would have fallen first.  A lot of that QPF happened in the initial WAA wave when the warm layer was very shallow and there was also a warm layer at the surface where it was like 33-34.  That combo killed what should have been a 5-7" changing to ice event imo. 

January 1, .81 QPF.  Again not all would have been snow, the primary tracked too far inland but if you subtract 2C that was a 1-3" snow/sleet to ice event.

January 3: perfect track rainstorm.  .28 QPF.  Should have been 2-3" 

1/25, .2 QPF but surface was around 33 and also a barely above 0 warm layer.  lets say 1-2"

1/31 to 2/2 .57 QPF.  The warm layer never got above 2c.  So make that all snow.  5-6"

2/7, .49 and the problem was all boundary layer...subtract 2C and that was a 4-5" snow

Last night the warm layer was never more then 1C and the boundary wasn't THAT WARM...that is a 3-5" snow under my alternate universe. 

So in this alternate universe where its 2C colder...DC is at 23-35" right now with a month of snow climo left and a pretty good pattern ahead.  Looking at a top 10% snowfall winter maybe!   I think my point WRT what the biggest issue is holds some validity.  

[aldie 22]

1 minute ago, WinterWxLuvr said:

They aren’t storms for the most part. Measly little 1012 lows aren’t what I’d call storms

All I know is i'm probably going to measly my way to 30" this season at one of my locations and probably 20-25" at the other. If that happens I will be pretty dang please considering the doom and gloom heading into the winter. 

[StormchaserChuck!]

GFS ensembles are rain

Edit: maybe ice, but it's taking that -PNA track

[SomeguyfromTakomaPark]

The swath of snow looks comically large on the 12z GGEM for Tuesday.  It’s snowing the same 6 hour period from Kentucky all the way to Nova Scotia. 

[EHoffman]

3 minutes ago, psuhoffman said:

But there was no HECS storm in 2015 or 2014 and those were considered good winters.  You are right...there wouldn't have been a HECS storm this year so far in DC regardless of the temp issues but let me make a point by playing an "alternate universe" where its 2C colder from 700mb on down in DC.  I think this is a fair temp to assume may have changed in the last 20 years due to a combo of AGW, UHI, and simply the current on fire base states of the Pacific and Atlantic oceans!

 I am going through every storm where if you subtract 2C from the column h7 to the surface and exactly what that would have meant to the result in DC proper (not necessarily National airport in that lava pit they take measurements at).  So storms where that would have got the surface down to a supportive temp for snow (say 33-34) and gotten the column above that below freezing.  I am going to be conservative but fair.

Dec 14th DC recorded 1.06 from a wave.  Not all of that would have been frozen...it was a cold boundary sinking south.  I got about 3" up here but the best moisture actually was suppressed SOUTH of me.  Problem was even with a perfect wave track the boundary layer was scorched in the coastal plain.  It was upper 30's rain.  You subtract 2C from that and it ended as 2-4" of snow. 

Dec 16th DC recorded 1.11 QPF.  Not all of that would have been snow if you subtract 2C... eventually the warm mid level would have won out...but at least 5-7" would have fallen first.  A lot of that QPF happened in the initial WAA wave when the warm layer was very shallow and there was also a warm layer at the surface where it was like 33-34.  That combo killed what should have been a 5-7" changing to ice event imo. 

January 1, .81 QPF.  Again not all would have been snow, the primary tracked too far inland but if you subtract 2C that was a 1-3" snow/sleet to ice event.

January 3: perfect track rainstorm.  .28 QPF.  Should have been 2-3" 

1/25, .2 QPF but surface was around 33 and also a barely above 0 warm layer.  lets say 1-2"

1/31 to 2/2 .57 QPF.  The warm layer never got above 2c.  So make that all snow.  5-6"

2/7, .49 and the problem was all boundary layer...subtract 2C and that was a 4-5" snow

Last night the warm layer was never more then 1C and the boundary wasn't THAT WARM...that is a 3-5" snow under my alternate universe. 

So in this alternate universe where its 2C colder...DC is at 23-35" right now with a month of snow climo left and a pretty good pattern ahead.  Looking at a top 10% snowfall winter maybe!   I think my point WRT what the biggest issue is holds some validity.  

Really interesting stuff, the theme of Metro DC snow has always been razor thin since as long as I've been here, but back in the day it would break our way seemingly more often.  I wonder what kind of affect global warming as a whole has on our region; we can't exactly afford a 1-2C degree increase in most storms, and it seems like we just can't push through any more to just get under freezing.  I feel like I'm living in the southern St. Mary's Co of 20 years ago, if that makes any sense.

[psuhoffman]

1 hour ago, WinterFire said:

If I had to guess, I'd say part of it is sea surface temperatures--if the Atlantic is warming, it would make it much more difficult to get cold and stay cold in the costal plain. Unfortunately since that's global warming-driven, there's not much we can do about that. But would a northern-stream dominant flow also have an impact? I.e., are systems required to dig more without drying out too much (which seems to have been happening with nearly every storm inside 72 hours), which makes any set up pretty precarious? Maybe it's grasping at straws, but that is something that (hopefully) doesn't stick around forever, and wouldn't necessarily imply that even moderate snow in the DC-Baltimore area is just shy of a lost cause...

the hell you say!  ICE...lots and lots and lots of ICE and dump trucks...we can solve this.  Where is that American can do spirit!

[psuhoffman]

1 hour ago, Wentzadelphia said:

12z icon looks much farther SE. I can’t tell if it’s doing a NAM/CMc progression though, don’t have H5 yet just slp/precip

Not making any forecasts for something that far out yet...but the seasonal pattern as well as the progression argues that is more a risk then the phased bomb up to our west solutions we were seeing the last few days.  That never made sense imo.  

[SomeguyfromTakomaPark]

Just now, psuhoffman said:

the hell you say!  ICE...lots and lots and lots of ICE and dump trucks...we can solve this.  Where is that American can do spirit!

We need some kind of giant sun filter in space to reduce solar insolation. 

[ers-wxman1]

During La Niña, models tend to over amplify weather systems several days out from onset. Overamped, too much moisture, only to see it correct toward the onset time. This latest event is a prime example as across the board guidance was giving a 6-10” area wide event and more like 10”+ on the euro, only to cave to a minor system...even by I-70 standards. Last storm very similar with the euro giving 25-30” at day 4/5 only to be cut back. For the hobbyist, it might be a sting to the gut, but for those working in the field, the inconsistency and wild swings have made forecast ops and communication to high level partners even up into high tier Gov partners a nightmare! Briefings for these “major” events that crop up at day 3-5 in NWP gain attention quickly then to have the rug pulled after you’ve messaged people is tough. One factor, could be minor, but it is a factor in such inconsistent data is the lack of domestic air travel in the U.S. we know the euro model in particular relies on aircraft data which air travel is 1/10th of what it was. Same with other guidance. Perhaps other factors we don’t know about. Niña years are tough as it is. Two conclusions I can draw from this season is... 1) the euro is not what the euro was, and 2) the NAM is useful outside its perceived “wheelhouse”. NAM is great at depicting changes, details in the pattern evolution that is not seen in the globals. It’s done well this season in that regard, overdone with front end waa snow.  3) it’s guidance only! Not verbatim. Know your patterns and climo vs model chasing. 
 

I expect the same trends with all the weather systems depicted through the 2/20 time frame. 

[ravensrule]

51 minutes ago, stormtracker said:

Trust me, by Monday's runs there won't be a storm.  It'll be a strung out piece of shit.

What happened to my favorite bus driver from back in the day?. It appears the bus needs a full overhaul  

[clskinsfan]

UK on board for Tuesday. Better NW obviously.

[jewell2188]

1 hour ago, stormtracker said:

Trust me, by Monday's runs there won't be a storm.  It'll be a strung out piece of shit.

I think this is rather logical....why go against the seasonal trend and that tends to be cloudy and dreary versus snowy. 

[Maestrobjwa]

1 minute ago, clskinsfan said:

UK on board for Tuesday. Better NW obviously.

I still don't get why p-type is an issue here...

[Miss Pixee]

4 hours ago, psuhoffman said:

I totally get the frustration in DC. Thing is it’s been a failure of boundary temps not pattern. I don’t know what to say. This has been the pattern since Dec 1 and the last month!   This looks like a match to every big DC snow period.

 

And we’ve had perfect track after perfect track SWs this winter. I count about 5 storms that frankly everything went EXACTLY right for a DC snowstorm and DC got a 37 degree rain or mix event. I don’t know what to say and frankly I don’t even know what DC needs to get snow anymore. Colder is the obvious answer but if a storm takes the perfect track colder would have  suppressed it. If the amount of suppression it takes to get cold enough is so much so that it squashed any wave that’s a problem. And don’t bring up Dallas. They aren’t near the coast east of mountains. Totally different climate. 

Fortunately got a couple of inches from the last storm. I'm more curious about the temp layers. What's the deal with all the frz rain/sleet/ice instead of snow? Its like the air patterns are all funky. Don't get me started on the maps people keep posting. BTW it isn't as if DC is its own entity...I heard these same arguments about Richmond.

Mother nature trumps, no matter what we think/say.

[Scarlet Pimpernel]

1 minute ago, Maestrobjwa said:

I still don't get why p-type is an issue here...

I'm not sure how accurate this is, so take with a grain of salt...

I'd wager it's partly due to the fact that the (Arctic) cold here is pretty shallow.  We're not exactly in the "center" of it all.  It's apparently well-entrenched at and near the surface, at least this side of the Appalachians.  But we're sort of on the edge of the main Arctic push it seems as these storms approach, enabling the mid-levels to warm even as the near-surface digs in with cold.

[WinterWxLuvr]

6 minutes ago, clskinsfan said:

UK on board for Tuesday. Better NW obviously.

That will change LOL.

[Bob Chill]

3 minutes ago, Maestrobjwa said:

I still don't get why p-type is an issue here...

Look at the "highway" height pattern at h5 leading in. Then take a look at midlevel (850) winds. Pumping out of the southwest too. That's what runs the moisture up and mix is part of the solutions (assuming models are right). There will be little if any snow punching deep into the arctic airmass because it's literally a brick of cold dry air. The battle zone is where the action is and the battle zone includes midlevel temp problems. It can def switch to a snowier solution but we need confluence to build (horizontal highways) to our north. That will fight off the warm surge. Anything is possible really. It's very touchy even at close range. 

[87storms]

22 minutes ago, ers-wxman1 said:

During La Niña, models tend to over amplify weather systems several days out from onset. Overamped, too much moisture, only to see it correct toward the onset time. This latest event is a prime example as across the board guidance was giving a 6-10” area wide event and more like 10”+ on the euro, only to cave to a minor system...even by I-70 standards. Last storm very similar with the euro giving 25-30” at day 4/5 only to be cut back. For the hobbyist, it might be a sting to the gut, but for those working in the field, the inconsistency and wild swings have made forecast ops and communication to high level partners even up into high tier Gov partners a nightmare! Briefings for these “major” events that crop up at day 3-5 in NWP gain attention quickly then to have the rug pulled after you’ve messaged people is tough. One factor, could be minor, but it is a factor in such inconsistent data is the lack of domestic air travel in the U.S. we know the euro model in particular relies on aircraft data which air travel is 1/10th of what it was. Same with other guidance. Perhaps other factors we don’t know about. Niña years are tough as it is. Two conclusions I can draw from this season is... 1) the euro is not what the euro was, and 2) the NAM is useful outside its perceived “wheelhouse”. NAM is great at depicting changes, details in the pattern evolution that is not seen in the globals. It’s done well this season in that regard, overdone with front end waa snow.  3) it’s guidance only! Not verbatim. Know your patterns and climo vs model chasing. 
 

I expect the same trends with all the weather systems depicted through the 2/20 time frame. 

makes sense.  what's your take on the tuesday system?  assuming it trends towards weaker/drier as suggested, it looks like it has the best setup ahead of it.  that said, with so many different waves it might be difficult for one wave to amplify/dominate.  to my hobbyist eyes, it looks like it will be dependent on where the boundary sets up.  further southeast would imply more wiggle room for a wave to jet through and not warm things up too much.  too far north and you end up with toasty mids even with healthy surface temps (like saturday).

[stormtracker]

So we're all skipping over the fact that the NAM completely shit the bed with the Saturday system now?  Like it literally fell apart.

[WinterWxLuvr]

1 minute ago, stormtracker said:

So we're all skipping over the fact that the NAM completely shit the bed with the Saturday system now?  Like it literally fell apart.

Were you expecting different?

[EHoffman]

1 minute ago, stormtracker said:

So we're all skipping over the fact that the NAM completely shit the bed with the Saturday system now?  Like it literally fell apart.

Just like with this past storm, I do believe the writing is on the wall for Saturday.  NAM has been money starting trends at this time period this winter.

[ers-wxman1]

4 minutes ago, 87storms said:

makes sense.  what's your take on the tuesday system?  assuming it trends towards weaker/drier as suggested, it looks like it has the best setup ahead of it.  that said, with so many different waves it might be difficult for one wave to amplify/dominate.  to my hobbyist eyes, it looks like it will be dependent on where the boundary sets up.  further southeast would imply more wiggle room for a wave to jet through and not warm things up too much.  too far north and you end up with toasty mids even with healthy surface temps (like saturday).

I say trend is your friend. Trends weaker, drier over time. 

[EastCoast NPZ]

30 minutes ago, SomeguyfromTakomaPark said:

We need some kind of giant sun filter in space to reduce solar insolation. 

Sulfates!

[stormtracker]

1 minute ago, EHoffman said:

Just like with this past storm, I do believe the writing is on the wall for Saturday.  NAM has been money starting trends at this time period this winter.

Yup.  Can't really shit on the NAM this winter.  It's been sniffing out trends

[adelphi_sky]

32 minutes ago, EHoffman said:

Really interesting stuff, the theme of Metro DC snow has always been razor thin since as long as I've been here, but back in the day it would break our way seemingly more often.  I wonder what kind of affect global warming as a whole has on our region; we can't exactly afford a 1-2C degree increase in most storms, and it seems like we just can't push through any more to just get under freezing.  I feel like I'm living in the southern St. Mary's Co of 20 years ago, if that makes any sense.

In addition, I can't recall a time where all models were wrong 24 hours out. If I recall, they used to get a good grip on things inside 24 hours. But lately, we've gone from frozen precip to just rain on models inside of 24 even as the radar fills in from the West or South. Even King Euro is having problems a day out. I get there are shifts. But that last minute nothing sandwich that appeared on Wednesday was just insane.