December Medium/Long Range Discussion

[Weather Will]

Just now, WinterWxLuvr said:

Some people here are DC and east. There’s a 40 on the map you posted sitting right beside of DC. You’re not overcoming 40 with rates.

Of course, I still believe that the cad will been more stout than forecast and that any warmup will be very brief. I think the places from here on east are gonna get creamed once that low gains enough latitude to put us in the back side.

The 40 I think is at 3pm.  By 10 pm surface temps are falling toward freezing and rates are still good.

[CAPE]

3 minutes ago, WinterWxLuvr said:

Some people here are DC and east. There’s a 40 on the map you posted sitting right beside of DC. You’re not overcoming 40 with rates.

Of course, I still believe that the cad will been more stout than forecast and that any warmup will be very brief. I think the places from here on east are gonna get creamed once that low gains enough latitude to put us in the back side.

Gotta have some backside love over here.

Did I just send out an RR signal?

[Weather Will]

Let’s hope EURO moves toward GFS

[CAPE]

2 minutes ago, WinterWxLuvr said:

Yes. That’s your hole card. Now if you get the cad to do it’s work, you’ll be good at the beginning as well.

The CAD will look good at the beginning, but one thing you learn living here is how quickly it can be overcome with marine warmth when there is an easterly fetch. If we had a true blocking pattern with an ideal slow moving/quasi stationary 50-50 low, the cold would stay more locked in here, and it would probably just sleet for a time rather than rain.

[LeesburgWx]

Talk about whiplash. I go to sleep after the pummeling 00z GFS to then wake up and read about the Euro and it’s ENS just to be pulled right back in now after the 06z GFS and it’s ENS. I still can’t push my chips in until all models agree. But Euro does look like an outlier

[40westwx]

56 minutes ago, MillvilleWx said:

This is how you get your 2-3"/hr snowfalls. 7H and 85H frontogen with this setup is silly.

oh yeah!

[CAPE]

Good synopsis from Mount Holly this morning-

00Z Guidance retains rather impressive run-to-run consistency with respect to timing, track, and associated thermal profiles with the low, and this is perhaps helped by the progressive hemispheric pattern which tends to favor more predictability than amplified blocking patterns. Consequently despite considerable uncertainty regarding the details of this system (more on that below) do have higher than average confidence that at least portions of our area will see potentially significant impacts from this system. The one thing to point out is that the mid-lvl wave associated with this system is still over the Pacific which does favor at least some caution in becoming too confident although modern Data Assimilation is fairly robust even in regions of observational sparsity.

Unfortunately (or fortunately if you look at it from my perspective) it is too early to get specific about ptypes and snow amounts, as the low`s track near to the coast will almost certainly result in some ptype transition zone. Furthermore this transition zone will likely ebb and flow as mesoscale lift (e.g. FGEN) results in dynamical cooling. That being said the antecedent airmass does look primed for wintry precipitation, with pre-storm dewpoints likely in the single digits or low- teens which should support some fairly notable wet-bulbing with the first batch of precip. The question then becomes can the intensity of the precipitation and associated dynamical cooling become enough to offset the increasing warm advection associated with the low? The next question is how robust will precipitation be on the back side of the low Wednesday night as it pulls away from the area, and cold advection begins? We should have more answers to these questions in the next couple days we enter the Mesoscale model window.

[MillvilleWx]

1 minute ago, CAPE said:

Good synopsis from Mount Holly this morning-

00Z Guidance retains rather impressive run-to-run consistency with respect to timing, track, and associated thermal profiles with the low, and this is perhaps helped by the progressive hemispheric pattern which tends to favor more predictability than amplified blocking patterns. Consequently despite considerable uncertainty regarding the details of this system (more on that below) do have higher than average confidence that at least portions of our area will see potentially significant impacts from this system. The one thing to point out is that the mid-lvl wave associated with this system is still over the Pacific which does favor at least some caution in becoming too confident although modern Data Assimilation is fairly robust even in regions of observational sparsity.

Unfortunately (or fortunately if you look at it from my perspective) it is too early to get specific about ptypes and snow amounts, as the low`s track near to the coast will almost certainly result in some ptype transition zone. Furthermore this transition zone will likely ebb and flow as mesoscale lift (e.g. FGEN) results in dynamical cooling. That being said the antecedent airmass does look primed for wintry precipitation, with pre-storm dewpoints likely in the single digits or low- teens which should support some fairly notable wet-bulbing with the first batch of precip. The question then becomes can the intensity of the precipitation and associated dynamical cooling become enough to offset the increasing warm advection associated with the low? The next question is how robust will precipitation be on the back side of the low Wednesday night as it pulls away from the area, and cold advection begins? We should have more answers to these questions in the next couple days we enter the Mesoscale model window.

I need to get myself back east because this is literally everything I've been mentioning. There will come a time

[Weather Will]

Euro is rolling...may the force be with us....

[Weather Will]

WB 6z EURO 1pm wed tick se

[Weather Will]

WB 6z EURO 4pm, again little se of 0z

[Weather Will]

WB 6z EURO 7pm, also tick se

[H2O]

Really need to see these side by side from current run to previous to see what the movement is

[Eskimo Joe]

06z OP Euro appears SE of its 00z counterpart.

[Weather Will]

WB 6z EURO

[Ji]

2 minutes ago, Weather Will said:

WB 6z EURO 7pm, also tick se

do you have the low placement?

[MillvilleWx]

Euro made a 25-30 mile tick to the SE with the progression of the SLP and can be seen looking closely at 925mb and 850mb with the winds and it showed with the depth and extension west of the warmer air within the boundary layer. This was actually a step in the right direction. Also, I think the CAD is underdone considering the surface setup with the HP positioning over Quebec City and a strength of 1038mb. Thicknesses reflected were in line with GFS despite being more robust in the surface reflection. I think this will trend more favorable in the short term. Question is the tuck of the SLP once it gets to ORF. If it stays even 50 miles off the coast, we are looking at an epic run for many. The western crew and northern crew would undoubtedly get obliterated with that run. Absolutely no question. 

[Weather Will]

WB 6z EURO v 0z snow map 

[Weather Will]

WB 6Z v 0z 925

[yoda]

Damn... really wish the 06z EURO went out one more frame... looked like the CCB was going to be going nicely for us

[Weather Will]

Not big change but agree that it edged back se this run. Did not continue NW.  I mean every 40 mile shift is huge either way.

[Ji]

4 minutes ago, Weather Will said:

Not big change but agree that it edged back se this run. Did not continue NW.  I mean every 40 mile shift is huge either way.

that looks like a big change...i went from +2 to -1 at 00z at 925. 3 degres!

[MillvilleWx]

5 minutes ago, yoda said:

Damn... really wish the 06z EURO went out one more frame... looked like the CCB was going to be going nicely for us

It was gonna be epic. No doubt. 5H was pure weather porn

[BristowWx]

5 minutes ago, yoda said:

Damn... really wish the 06z EURO went out one more frame... looked like the CCB was going to be going nicely for us

We are about 48hrs from WSWatches...if all holds..totally stoked about that alone. 

[yoda]

1 minute ago, MillvilleWx said:

It was gonna be epic. No doubt. 5H was pure weather porn

Just checked that and wow... indeed you are right.  That was weenie porn indeed

[40westwx]

2 hours ago, MillvilleWx said:

The 850-700mb frontogen on the 06z GFS is otherworldly. Whoever stays all snow with this system is gonna shovel well over 12". Mark my words. 

Crazy aviation shift over here this evening, so bare with me.

We need more analysis like this.

[SomeguyfromTakomaPark]

13 minutes ago, yoda said:

Damn... really wish the 06z EURO went out one more frame... looked like the CCB was going to be going nicely for us

I’d be so pumped if we get an event that is snow —>mix/rain —> CCB crushing.  Gimme an inch or two on the front and then 3-6 in a short span on the back and I’ll be satisfied. 

[40westwx]

20 minutes ago, Weather Will said:

WB 6Z v 0z 925

you see that coma shaped area of below 0 to the south and west of DC.. I think the model picking up on the dynamics of the system.. it looks like thats where wind shifts around to the north and banding sets up.. 

[40westwx]

9 minutes ago, DCTeacherman said:

I’d be so pumped if we get an event that is snow —>mix/rain —> CCB crushing.  Gimme an inch or two on the front and then 3-6 in a short span on the back and I’ll be satisfied. 

Jan 2011? That was one of my favorite storms!

[yoda]

10 minutes ago, MillvilleWx said:

It was gonna be epic. No doubt. 5H was pure weather porn

Tasty