February Medium/Long Range Thread

[Fozz]

meh

[MN Transplant]

Ok, summary for those waking up.  Still a jackpot to the south and east.  Huge difference in how big/strong the storm gets, which affects the totals to the north and west.  10:1 snow amounts for DC:

• GFS:  5" (06z), 4" (00z)
• Euro:  6.5" (06z), 9" (00z)
• Canadian:  0.5" (00z)
• ICON:  10" (06z), 5" (00z)
• Ukie:  2" (00z)
• Euro AI:  4.5" (00z)

 

[BristowWx]

44 minutes ago, Weather Will said:

WB 6Z EURO tick East. Honestly, looks like the eastern shore gets slammed.  Plan a beach trip...my expectations are 3-6 inches in sw Frederick

Putting aside the HECS hope ..that looks pretty good for some of us.  Won’t be warm or sleety.  Today is salvage day

[WxUSAF]

2 nights ago, most guidance showing 1-2’ MECS: 4.5 new pages in the LR thread 

Last night: mostly a total disaster: 25 new pages in the LR thread 

[SomeguyfromTakomaPark]

4 minutes ago, MN Transplant said:

Ok, summary for those waking up.  Still a jackpot to the south and east.  Huge difference in how big/strong the storm gets, which affects the totals to the north and west.  10:1 snow amounts for DC:

• GFS:  5" (06z), 4" (00z)
• Euro:  6.5" (06z), 9" (00z)
• Canadian:  0.5" (00z)
• ICON:  10" (06z), 5" (00z)
• Ukie:  2" (00z)
• Euro AI:  4.5" (00z)

 

Looks pretty good for a solid cold storm.  Now maybe we can creep it back towards something a bit beefier.  Still time. 

[MDScienceTeacher]

1 minute ago, MN Transplant said:

Ok, summary for those waking up.  Still a jackpot to the south and east.  Huge difference in how big/strong the storm gets, which affects the totals to the north and west.  10:1 snow amounts for DC:

• GFS:  5" (06z), 4" (00z)
• Euro:  6.5" (06z), 9" (00z)
• Canadian:  0.5" (00z)
• ICON:  10" (06z), 5" (00z)
• Ukie:  2" (00z)

 

Other than the ICON, if this verifies than it is a total and complete fail.  Two days ago, we had every single model in our camp except for the GFS.  and several people said said that there is no way in hell every model would cave to the GFS.. and here we fucking are.  I cant believe what I am seeing.. how could this happen again?

 

[mappy]

5 hours ago, clskinsfan said:

Yep. ban your ass to the correct forum. 

FWIW, if we tell TSSN to go, Mitch would need to follow. They’re from the same local. Choose your battles wisely. 

[Ji]

2 nights ago, most guidance showing 1-2’ MECS: 4.5 new pages in the LR thread 
Last night: mostly a total disaster: 25 new pages in the LR thread 

I think the track is pretty much set. We just have to hope for a stronger storm.

[bncho]

hoping for a cave to the NAM

[TheColtrane]

2 minutes ago, bncho said:

hoping for a cave to the NAM

Please do hitch your wagon to the NAM's star 

[IronTy]

Man I made the mistake of coming here first instead of weatherbell when I woke up.  Based on posts I was expecting 70F and sunny next Thursday.  Instead the models are still showing a foot of snow.  Shoulda went to WB first and avoided the blood pressure spike.  

[SomeguyfromTakomaPark]

8 minutes ago, MDScienceTeacher said:

Other than the ICON, if this verifies than it is a total and complete fail.  Two days ago, we had every single model in our camp except for the GFS.  and several people said said that there is no way in hell every model would cave to the GFS.. and here we fucking are.  I cant believe what I am seeing.. how could this happen again?

 

It’s not the likeliest thing (to have the GFS win out) but it happens from time to time. Also, still 100 hours out so a lot can change.  

[concentricEye]

Really good write up from LWX regarding subtle pattern changes that have led to less phasing in recent runs. Threading the needle rarely works in everyone’s favor.



.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
...Looming Wednesday-Thursday Winter Storm Threat Yet to be
Fully Resolved...

The focus of the long term period continues to be on an East
Coast winter storm threat and its potential impacts to the Mid-
Atlantic region. For the better part of the last week, ensembles
have been hinting at the potential of significant snow around
February 20, though there are some trends in the last 48 to 72
hours worth noting.

For mid week, upper-level pattern/ensemble mean 500 hPa height
trends the last couple of days have been for (1) a somewhat
weaker northern stream upper low descending into the northern
Plains, and (2) a weaker West Coast/Rockies ridge likely due at
least in part to a stronger and faster shortwave progged to be
approaching the Pacific Northwest. It appears these trends
reached a critical threshold in the 15/12Z guidance suite, with
a bimodal distribution among varying ensembles slightly favoring
less meridional flow and a more offshore surface low track. This
pattern shift, if it verifies, would allow the southern stream
shortwave to not be fully caught as quickly by the slightly less
amplified northern stream upper low, with less phasing resulting
in the further southeast/offshore track. The trend was most
obvious in the EPS (ECMWF ensemble) and MOGREPS-G (UKMET
ensemble), which showed a southeastward shift in the axis of
highest snowfall probabilities. The trend persisted through the
15/18Z cycle, and appears to have stabilized a bit in the 16/00Z
cycle (though with some -increasing- spread).

Interestingly, some machine learning guidance (i.e. the
GraphCast GFS and ECMWF-AIFS) had been showing this offshore
track potential for several days now. However, their latest runs
have trended a bit to the northwest (closer to the coast),
perhaps indicative of a stabilizing or even reversal in trends.

Also of note, although the highest probabilities for 6- and
12-inch plus snows have shifted southeastward for the time
being, probabilities for 2 inches of snow remain elevated. This
suggests that at least some snow is highly likely (probably with
the passing northern stream upper trough/low even in a less
amplified scenario).

It is important to note this trend, but also the continued
variability and likely future shifts in the track. Despite the
shift in ensemble means and the rather low amounts of snow
locally in the 16/00Z CMC and UKMET deterministic, the ECMWF
deterministic remains steadfast in solid warning level snow for
much of the region. The recent GFS and ICON deterministic also
indicate a high likelihood of warning level snow for at least
roughly the southeastern half of the CWA.

Given the amount of cold air, moisture, and energy present, the
potential for a significant winter storm still exists and needs
to be closely monitored. But, the exact details of how this all
unfolds remain unclear this far in advance.


.

[MDScienceTeacher]

5 minutes ago, Ji said:

I think the track is pretty much set. We just have to hope for a stronger storm.

How does this happen.  Five days ago, I said its a rug pull and I wouldnt let my self get pulled in again.. I am hopeless.

And I dont want to hear the crap about setting expectations or how 6 inches of snow is great or how we werent going to get a HECs to begin with.. I dont want to hear it.  Because I have news for you.. the fringe is looking boxing day-ish.  there I said it.  And I dont think I can take another day of snow tv while sitting on an winter storm warning  for 6-12 inches... waiting for it to accumulate as someone to our south is getting 20 inches of snow.   The impossible happened.  for the first time in model history (ever) the GFS was right and every other model was wrong.  

[Random Chaos]

5 minutes ago, MDScienceTeacher said:

Other than the ICON, if this verifies than it is a total and complete fail.  Two days ago, we had every single model in our camp except for the GFS.  and several people said said that there is no way in hell every model would cave to the GFS.. and here we fucking are.  I cant believe what I am seeing.. how could this happen again?

 

It’s only a fail if you look at "snow in my back yard" measure. If anything this is a huge sucess for the models. We’ve seen remarkable consistency from 6 days out to 4 days out with only minor track changes, but because of the range minor changes result in significant differences in who gets snow and who doesn’t. We’ve been consistently seeing a southern eastern shore/Ocean City axis with models frequently, but not always extending the precip shield over the DC metro. We’ve consistently seen a coastal bomb cyclone but differences in exactly where the northern turn occurs that impact totals here but not Ocean City. We always sit on a razors edge here for max potential, and the models have been crazy consistent in that there is a storm to within a very small north/south zone at very good temporal range.

[21chuck]

48 minutes ago, RevWarReenactor said:

Latest guidance falls in line with the seasonal trend of everything south and east of the area. Delaware Beaches must be having a record run this year. What will this be the 3rd 12+ storm if this verifies?

For Rehoboth area, I think they've had about 10 inches, then 5 inches, now this. Still ridiculous. 

[RevWarReenactor]

13 minutes ago, MDScienceTeacher said:

Other than the ICON, if this verifies than it is a total and complete fail.  Two days ago, we had every single model in our camp except for the GFS.  and several people said said that there is no way in hell every model would cave to the GFS.. and here we fucking are.  I cant believe what I am seeing.. how could this happen again?

 

This had rug pull written all over it. Just based on climo. We get 18-24 foot snowstorms for all of I-95 like once every 20-30 years. The models have been pretty bad this year with drastic shifts at about 100 hours. I never bought any of it. 

[WxUSAF]

8 minutes ago, Ji said:

I think the track is pretty much set. We just have to hope for a stronger storm.

To respond to @psuhoffmans posts from yesterday, the difference between H5 and surface is pretty weird here. Heaviest snow is north of H5 shortwave track usually. Using 0z euro as an example, even the southern stream wave tracks roughly from RDU to ORF. That should be pretty good for us! Northern stream goes well to our north! Should be good for…Albany? Ultimately, I think our problem mostly is the northern stream isn’t diving south farther west as it did with some of the MECS-HECS runs. So we’re getting either a partial phase or it’s even acting as a kicker to the southern wave (ggem). 

[Kmlwx]

1 minute ago, RevWarReenactor said:

This had rug pull written all over it. Just based on climo. We get 18-24 foot snowstorms for all of I-95 like once every 20-30 years. The models have been pretty bad this year with drastic shifts at about 100 hours. I never bought any of it. 

Congratulations on your win

[RevWarReenactor]

3 minutes ago, Kmlwx said:

Congratulations on your win

I think if expectations are reset at 3-6 inches. Won't be disappointed. Will still be a nice little storm, and anything more is a bonus. 

[CAPE]

2 minutes ago, Random Chaos said:

It’s only a fail if you look at "snow in my back yard" measure. If anything this is a huge sucess for the models. We’ve seen remarkable consistency from 6 days out to 4 days out with only minor track changes, but because of the range minor changes result in significant differences in who gets snow and who doesn’t. We’ve been consistently seeing a southern eastern shore/Ocean City axis with models frequently, but not always extending the precip shield over the DC metro. We’ve consistently seen a coastal bomb cyclone but differences in exactly where the northern turn occurs that impact totals here but not Ocean City. We always sit on a razors edge here for max potential, and the models have been crazy consistent in that there is a storm to within a very small north/south zone at very good temporal range.

Guidance has consistently depicted southern stream energy inducing low pressure in the Northern Gulf and tracking NE off the NC coast. The differences have been wrt degree of interaction with NS energy and the potential to bring SLP closer to the coast with higher precip totals further NW.

I also find it funny how universal the 'GFS caved' mantra was yesterday afternoon, and now somehow its the other way around lol. 

[bncho]

9 minutes ago, RevWarReenactor said:

This had rug pull written all over it. Just based on climo. We get 18-24 foot snowstorms for all of I-95 like once every 20-30 years. The models have been pretty bad this year with drastic shifts at about 100 hours. I never bought any of it. 

Sure, it was hard to believe this was actually going to happen.

But it's a real dagger to the heart when at 12z we are thinking that the GFS and ICON caved.

[Bob Chill]

25 minutes ago, WxUSAF said:

2 nights ago, most guidance showing 1-2’ MECS: 4.5 new pages in the LR thread 

Last night: mostly a total disaster: 25 new pages in the LR thread 

Other than some op eye poppers, I never saw much evidence for a big/classic storm. The term big ones sniffed out early also includes ops showing big solutions over and over. We really only had a mid range pocket of solutions that did that. For every big run there was a scary one and analogs never stacked up with big solutions. Hard to ignore that and remain grounded in reality lol. 

This storm does seem primed to dump a foot on someone. Small area like the last one. Overall snow shield is much larger this go around. I'd like to think it makes a lot of people happy but I'm second guessing that lol. 

[aldie 22]

4 minutes ago, CAPE said:

Guidance has consistently depicted southern stream energy inducing low pressure in the Northern Gulf and tracking NE off the NC coast. The differences have been wrt degree of interaction with NS energy and the potential to bring SLP closer to the coast with higher precip totals further NW.

I also find it funny how universal the 'GFS caved' mantra was yesterday afternoon, and now somehow its the other way around lol. 

Still sort of feels like this is a delicate situation. I wouldn't expect anything dramatic now but shifts in either direction are certainly still on the table. It does feel like SE of here is pretty well established though

[mitchnick]

6 minutes ago, WxUSAF said:

To respond to @psuhoffmans posts from yesterday, the difference between H5 and surface is pretty weird here. Heaviest snow is north of H5 shortwave track usually. Using 0z euro as an example, even the southern stream wave tracks roughly from RDU to ORF. That should be pretty good for us! Northern stream goes well to our north! Should be good for…Albany? Ultimately, I think our problem mostly is the northern stream isn’t diving south farther west as it did with some of the MECS-HECS runs. So we’re getting either a partial phase or it’s even acting as a kicker to the southern wave (ggem). 

I'm sure you haven't looked at the 6z Nam very closely, but it simply parks the tpv over the Dakotas and appears to be all southern stream. Maybe that's a victory as well, to keep the tpv more or less stationary and let the southern vort pivot counterclockwise around it.  Of course, the kicker might just wreck that option  in future runs.

[nj2va]

6 minutes ago, CAPE said:

Guidance has consistently depicted southern stream energy inducing low pressure in the Northern Gulf and tracking NE off the NC coast. The differences have been wrt degree of interaction with NS energy and the potential to bring SLP closer to the coast with higher precip totals further NW.

I also find it funny how universal the 'GFS caved' mantra was yesterday afternoon, and now somehow its the other way around lol. 

“GFS will come around eventually”

”This is basically the fold we need by the GFS”

Way too much pure blind faith put into the Euro. The model isn’t right all the time, by a long shot. 

[paxpatriot]

4 hours ago, stormtracker said:

Was spending some quality time with the bf. Did I miss anything? 

TSSN was banished to the land of brotherly love and CLSKINS was banished to the land of wind and ghosts. Other than that, normal night on the board. 

[CAPE]

1 minute ago, aldie 22 said:

Still sort of feels like this is a delicate situation. I wouldn't expect anything dramatic now but shifts in either direction are certainly still on the table. It does feel like SE of here is pretty well established though

I think there could still be some adjustments. Maybe enough interaction-albeit late- such that the low slows down some, allowing better moisture transport further NW.

[Wonderdog]

9 minutes ago, CAPE said:

Guidance has consistently depicted southern stream energy inducing low pressure in the Northern Gulf and tracking NE off the NC coast. The differences have been wrt degree of interaction with NS energy and the potential to bring SLP closer to the coast with higher precip totals further NW.

I also find it funny how universal the 'GFS caved' mantra was yesterday afternoon, and now somehow its the other way around lol. 

Don't you think the GFS has been the most stable model with respect to how it has handled this storm to date?

[Allsnow]

4 minutes ago, mitchnick said:

I'm sure you haven't looked at the 6z Nam very closely, but it simply parks the tpv over the Dakotas and appears to be all southern stream. Maybe that's a victory as well, to keep the tpv more or less stationary and let the southern vort pivot counterclockwise around it.  Of course, the kicker might just wreck that option  in future runs.

It’s a path to victory as the tpv is usually very crushing for us on the east coast. We would just need the confluence to continue to weaken