December Medium/Long Range Discussion

[BristowWx]

1 minute ago, leesburg 04 said:

I moved away from Woodbridge for storms like this...recent years it feels like Woodbridge is creeping out this way. I expect to mix some with this thing if recent years are any indication but I'm definitely less worried than if I lived further SE. I honestly hope this thing comes to be and we all score!

I’ve noticed a difference over the years between Woodbridge and here even though it’s only about 15 miles NW.  either way you are solid unless there is some big changes.  

[CAPE]

Just now, leesburg 04 said:

I moved away from Woodbridge for storms like this...recent years it feels like Woodbridge is creeping out this way. I expect to mix some with this thing if recent years are any indication but I'm definitely less worried than if I lived further SE. I honestly hope this thing comes to be and we all score!

lol it would be nice but rarely does a winter storm make everyone happy. Climo is pretty tough here for snow in December without real deal cold in place. Still time for some track adjustments. For us easterners it will probably be snow to rain and back to snow. Hoping to catch some of the deform band on the backside.

[BristowWx]

1 minute ago, Buddy1987 said:

I thought 6z gfs looked a little more progressive with system although I couldn’t really sleep tonight just from being giddy with excitement so I may be wrong. 

It looked a little slower to me as I toggled back from 0z.  Not sure entirely.  

[Buddy1987]

Just now, BristowWx said:

It looked a little slower to me as I toggled back from 0z.  Not sure entirely.  

Other concern for me would be from a resolution side of things specifically wrt to cold air superiority where nam at end of run is a good several mb weaker with high pressure. Has it at 1031 instead of 1035-1037. That def bears watching. 

[BristowWx]

4 minutes ago, Buddy1987 said:

Other concern for me would be from a resolution side of things specifically wrt to cold air superiority where nam at end of run is a good several mb weaker with high pressure. Has it at 1031 instead of 1035-1037. That def bears watching. 

All valid concerns.  It’s what makes tracking fun and shitty at the same time. No sun angle concerns so that’s one to take off the list lol. 

[CAPE]

Just now, BristowWx said:

All valid concerns.  It’s what makes tracking fun and shitty at the same time. No sun angle concerns so that’s one to take off the list lol. 

Warm, wet soil though!

[Buddy1987]

8 minutes ago, BristowWx said:

All valid concerns.  It’s what makes tracking fun and shitty at the same time. No sun angle concerns so that’s one to take off the list lol. 

I went back here and compared the 6z gfs to the 0z Canadian and they are very similar with progression. Base of the trough looks to dig a little more on the Canadian right around 102-108 on 5h. By 114 however they are almost identical with the low placement right around Hatteras and the snow bomb is in full gear at that point. High pressure is slightly displaced to the east compared to the Canadian. All in all being picky but this is going to be one hell of a storm it looks like for majority of us. Monitoring for my aunt as well in CT and it’s crazy to see up there the whole state basically gets 3ft or just under.

[Buddy1987]

5 minutes ago, CAPE said:

Warm, wet soil though!

Cape are you that guy that gets into the heated debates when it comes to the soil temp etc? I never understood why people get all wrapped up in that. If it’s gonna dump it will take care of the rest.

[CAPE]

1 minute ago, Buddy1987 said:

Cape are you that guy that gets into the heated debates when it comes to the soil temp etc? I never understood why people get all wrapped up in that. If it’s gonna dump it will take care of the rest.

lol no. It's just become a running joke here over the years.

[SomeguyfromTakomaPark]

I saw the 00z 31 member probability of 6 inches of snow from the GEFS posted in the nyc thread and it looked very nice for dc.  Anyone have the 6z GEFS?

[Weather Will]

WB 6Z GEFS 

[nj2va]

This will be the first coastal that I’ll likely be out at Deep Creek...curious if the NW shield of precip is undermodeled in intensity/coverage on a model run like the 6z GFS.  

[LP08]

1 minute ago, Weather Will said:

WB 6Z GEFS 

Maybe only 4 absolute stinkers for the beltway crowd.  Great run.  Thanks!

[snowmagnet]

6 hours ago, Wentzadelphia said:

You guys recall any winters that had big mid December storms that didn’t end up being great seasons?

I just recall Dec 17, 2009 that started one of our biggest seasons. 

[WinterWxLuvr]

@MillvilleWx has talked about the cad aspect of this storm. The one thing that I can stress that I put 100% faith in is that cad, although not a true all cad setup here, always gets colder as you get closer. For this reason I think the likelihood of precip other than frozen will diminish as we get closer for those who are currently close to that possibility 

[Wonderdog]

1 hour ago, BristowWx said:

As depicted this will be one for the books. Still long way to go however. 

Are the Kuchera snow maps still wacked and if so why haven't they been fixed?

[TJ3]

6 hours ago, Wentzadelphia said:

You guys recall any winters that had big mid December storms that didn’t end up being great seasons?

I was only in grade school so the memory is fuzzy, but I don’t think DCA saw much snow January- March of ‘74 after the good ‘73 December snow. 

[nj2va]

Also to note, 6z GFS has precip breaking out for the SW parts of the forum within 100 hours.  

[osfan24]

2 hours ago, NorthArlington101 said:

We toss. Imagine getting a foot or slightly less while NYC and Boston are digging out of three feet. Doubt it goes down like that. I can't think of many actual big storms where we got significant snow here but then it crushed NYC and Boston. Most of the time when they get big storms, we either get it or it's a swing and miss here because it's just too far east of us.

[JakkelWx]

I'm hugging the CMC

[WinterWxLuvr]

I know we don’t care here but the snowfall in southern New England might be prodigious 

[Weather Will]

WB 6z EURO hr90, looks about the same as 0z at same time frame to my non expert eye...

[CAPE]

5 minutes ago, WinterWxLuvr said:

@MillvilleWx has talked about the cad aspect of this storm. The one thing that I can stress that I put 100% faith in is that cad, although not a true all cad setup here, always gets colder as you get closer. For this reason I think the likelihood of precip other than frozen will diminish as we get closer for those who are currently close to that possibility 

I generally agree, and that will probably be the case for the beginning of this event for sure. As the low tracks closer, the question becomes how much the upper levels warm. Not much of a risk out your way, but if the low is tucked in and the winds are screaming out of the east, the cold can erode fast. Pretty strong signal for this looking at the ensemble members. Hopefully things shift a bit over the next couple days,

[Wonderdog]

4 minutes ago, osfan24 said:

We toss. Imagine getting a foot or slightly less while NYC and Boston are digging out of three feet. Doubt it goes down like that. I can't think of many actual big storms where we got significant snow here but then it crushed NYC and Boston. Most of the time when they get big storms, we either get it or it's a swing and miss here because it's just too far east of us.

But isnt this storm really bombing out around our latitude as opposed to south of us?

[JakkelWx]

1 minute ago, CAPE said:

I generally agree, and that will probably be the case for the beginning of this event for sure. As the low tracks closer, the question becomes how much the upper levels warm. Not much of a risk out your way, but if the low is tucked in and the winds are screaming out of the east, the cold can erode fast. Pretty strong signal for this looking at the ensemble members. Hopefully things shift a bit over the next couple days,

Not good seeing the models are still looking like this and we're only 120 hours out. I'm starting to get worried about this

[Weather Will]

Latest NWS Sterling discussion good writeup:  

By Wednesday morning, an upper level trough will be digging south
and east across the Mississippi River Valley, taking aim toward the
TN/OH Valley`s. The aforementioned area of low pressure is progged
to consolidate over the eastern Carolinas Wednesday afternoon,
strengthening as it tracks along or just east of the Delmarva
Peninsula Wednesday night. At the same time, the upper trough will
take on a negative tilt as it approaches the Ohio Valley late
Wednesday and the right entrance of the jet positions itself nicely
in terms of upward motion and divergence aloft centering over the
CWA.

Precipitation associated with the system will overspread the area
Wednesday morning, a touch slower with the latest model runs, while
much of the area is at or below freezing. This will allow for snow
to the be the favored ptype initially. The model trends with the
high over or near Quebec have been stronger, helping to supply the
colder air on the eastern slopes of the mountains. Thereafter,
guidance wants to allow for warmer air to work its way along and
east of the I-95 corridor to produce a rain/snow mix Wednesday
afternoon and evening. Further north and west, thermal profiles
indicate an all snow event, with accumulating snow looking
increasingly likely. Model ensembles support this as well, with
fairly good agreement across the board, and probabilities of
exceeding 1/3/6" all increasing run to run.

At this time, an enhanced winter storm threat exists Wednesday and
Wednesday night along and west of the Blue Ridge Mountains,
potentially resulting in a disruption to travel, while a slight
winter storm threat along and east of the I-95 corridor. With a
touch slower progression of the system, models linger precipitation
into a good portion of Wednesday night as the low pushes away from
the coast Thursday morning. There is some discrepancy in this
progression between the global guidance, so this will have to be
ironed out in the coming days. Confidence is increasing with the
potential for accumulating snow and potential impact to the area,
but exact amounts and placement of the rain/snow line carries a
lower confidence at this time. Follow our latest forecast on this
system and potential impacts at weather.gov/lwx/winter.

[CAPE]

Just now, JakkelWx said:

Not good seeing the models are still looking like this and we're only 120 hours out. I'm starting to get worried about this

All I will be watching for future runs are 850/925 temps, and how far inland the 0c line gets. The 6z GFS was not good for our area. Need the low track a bit more offshore. I think any significant ridging out in front is problematic too wrt confluence and surface high strength/position. 

[nj2va]

9 minutes ago, Wonderdog said:

But isnt this storm really bombing out around our latitude as opposed to south of us?

Yeah, I think the reason the 6z gave those areas so much was due to the evolution of the 500 low...it closes off basically over the LI sound.

[Wonderdog]

Just now, nj2va said:

Yeah, I think the reason the 6z gave those areas so much was due to the evolution of the 500 low...it closes off basically over the LI sound.

You gotta like hearing the term "negative tilt"!

[JakkelWx]

4 minutes ago, CAPE said:

All I will be watching for future runs are 850/925 temps, and how far inland the 0c line gets. The 6z GFS was not good for our area. Need the low track a bit more offshore. I think any significant ridging out in front is problematic too wrt confluence and surface high strength/position. 

What's wrong with the GFS is the z500 vort setup. You have another NS that messes up the bowling ball causing it to tilt negative too early and it's rain for us here. 

The CMC doesn't have this problem. The bowling ball stays intact mostly, and doesn't tilt neutral/neg until in the right spot for us. FWIW the CMC and the GFS are both showing the HP in the upper 1030s, but the GFS weakens the arctic high sooner. The low on the CMC is actually even slightly closer, yet it's almost all snow here and points N and W. Big blizzard. 

Regardless, I think I'll see a correction colder as we get closer to the event. We aren't out of the woods yet

- How strong the secondary low or how far north it is in the OHV will determine Ptype

- How the z500 vort streams interact, how they tilt, things to watch are if the UL disturbance tilts negative too early

- How stacked the low is, as the CMC would have less southerly flow mucking up the mid levels than the GFS

All this will determine how many muthafukkas fall