January Medium/Long Range: A snowy January ahead?

[Allsnow]

2 minutes ago, mitchnick said:

Yes. 6z the 2 moved east.

 

1 minute ago, mitchnick said:

Here's a link to EuroAI products from free Euro site.

https://charts.ecmwf.int/?facets={"Product type"%3A["Experimental%3A AIFS"]%2C"Parameters"%3A[]%2C"Range"%3A[]%2C"Type"%3A[]}

Thanks 

[The Dude]

5 hours ago, wdrag said:

Good morning mid-Atlantic,

Can someone alert me (or post a reply)  if anyone there has been looking at Inauguration Day weather in of course DC.  In particular I'm looking for information regarding this possibly being the worst wintry Inauguration Day since 1961 (Kennedy Inaugural storm).  Seems to me--(my guess only) looks like Noon temps mid 20s with wind, a colder wind chill 10-15 and inch or 2 of snow still left on the ground?  If that were true,  did anyone review all the inauguration days for wintry conditions?  Rain doesn't bother me for my information.  Snow on the ground and temps below freezing are my interest. I see nothing in the headlines from LWX, but it might be buried somewhere--I just haven't taken the time to check.  Thank you,  Walt

Capital Weather Gang just did a nice write-up on Inauguration Day weather history.  Here's a gift link that should get you through the paywall:  https://wapo.st/4jhkaSX

 

 

[Bob Chill]

After some very shallow analysis it appears that every wave that may or may not affect us over the next 2 weeks has equal chances of rain, snow, sleet, zr or a combination of all. Wiggly progressive fire hoses have somewhere around a zero percent chance of being modeled correctly by ops beyond 4 days or so and even then. Ensembles are 12 guage shotgun blasts of all solutions. Good luck guessing right lol. 

[Warm Nose]

Current state of this sub

[WhiteoutMD]

3 minutes ago, Warm Nose said:

Current state of this sub

Don't bring out the football GIF

[RickinBaltimore]

37 minutes ago, The Dude said:

Capital Weather Gang just did a nice write-up on Inauguration Day weather history.  Here's a gift link that should get you through the paywall:  https://wapo.st/4jhkaSX

 

 

I was going to say I remember Reagan's 2nd inauguration was cold as hell.

[87storms]

Not sure if anyone can watch live, but I just got to the major upgrades in modeling presentation at ams. The euro and gfs are at 9 and 915 (CT), for those interested. You might be able to watch it via the ams website.

[wdrag]

46 minutes ago, The Dude said:

Capital Weather Gang just did a nice write-up on Inauguration Day weather history.  Here's a gift link that should get you through the paywall:  https://wapo.st/4jhkaSX

 

 

Thank you very much to you and Etta. The article had what I needed.  Regards, Walt

[MDScienceTeacher]

28 minutes ago, Bob Chill said:

After some very shallow analysis it appears that every wave that may or may not affect us over the next 2 weeks has equal chances of rain, snow, sleet, zr or a combination of all. Wiggly progressive fire hoses have somewhere around a zero percent chance of being modeled correctly by ops beyond 4 days or so and even then. Ensembles are 12 guage shotgun blasts of all solutions. Good luck guessing right lol. 

The Latest GEFS shows an increase in clustering of low pressure off the mid Atlantic coast during the 24th timeframe as compare with previous runs of the GEFS.  This could be pointing to a trend that will eventually lead to a cutter/ inland runner (like the op).  This would make sense given the fact that there is no block in place during that time period..  or it could be on to a big coastal low.  Or it could just mean nothing.  Two days ago we were talking about the 20-22 window.. now it is out another 10 days.  

[SomeguyfromTakomaPark]

10 minutes ago, MDScienceTeacher said:

The Latest GEFS shows an increase in clustering of low pressure off the mid Atlantic coast during the 24th timeframe as compare with previous runs of the GEFS.  This could be pointing to a trend that will eventually lead to a cutter/ inland runner (like the op).  This would make sense given the fact that there is no block in place during that time period..  or it could be on to a big coastal low.  Or it could just mean nothing.  Two days ago we were talking about the 20-22 window.. now it is out another 10 days.  

I think we still may have a mid week threat.  A lot can happen in 5-7 days in this pattern.  I wouldn't write it off just yet, have to wait and see how the weekend plays out before we can really nail down what will be our threat window(s).

[psuhoffman]

Good morning

Quick summary of what I see

The first threat Sunday is actually simple, but the cause for divergence across guidance is that its delicate.  There is a vigorous SW over western AK right now.  It's going to split over western Canada with a piece going east and merging into the TPV and another part diving into the trough, rounding the base and becoming our snow threat Sunday.  This energy activates the boundary.  It's pretty simple, how much energy and what track does this wave take.  But its delicate, its a relatively weak minor player in the overall flow so models will struggle with it, but this delicate weak piece of energy holds our fate wrt snowfall sunday.  

 

The next bigger threat involves major players on the hemispheric longwave scale, but it involves lots of them in a delicate intricate balancing act so its complicated.  

 

The main TPV (1 and 2) is going to elongate and eventually split.  How much energy resides with 1 and 2 and where 1 ends up and how quickly it clears out of the way to our north is a major factor.  How much energy trails with 2 and how it interacts with 3 is a major factor.  What 4 does and how it influences the tail of the trough is a factor.  And finally what the next major wave 5 does and whether if flattens or amplifies the downstream trough is a factor.  

There is no way guidance is going to lock all this in at this range, especially absent blocking to set firm guides in the flow for all these features.  But in general we want more energy to reside further west with 2 and 3 and less with 1 and that has been the trend across all guidance over the last 24 hours.  But don't expect this to be resolved quickly.  Even the crazy GFS idea of holding back so much energy that it becomes the next threat 48 hours later is not off the table and shows up on some individual members of the EPS.  

Lastly, what comes AFTER AFTER....

EPS continues to trend towards a much more friendly look for February.  It's already backing off on the crazy SER look it was suggesting.  It continues to trend towards lower heights near Hawaii which is a key, that look of the pac jet undercutting the WPO EPO ridge typically suggests troughs won't get stuck in the southwest and press east more.  It also pushes the WPO EPO ridge poleward and often leads to AO ridging over the top, which we are seeing more and more now on long range guidance.  This also helps to deepen troughs into the CONUS.  

This look puts a lot of pressure for the cold to press southeast.  Last nights op euro is a good example of what that pattern would actually look like because it matches the h5 of the EPS very closely. 

The SER is there at H5 but look at what it actually looks like where it matters

We are very much in the game for boundary waves in that look.  It's February and we don't need as much of a perfect pattern to get snow the first half of February as just about every other time of the year.  If that is the worst look this winter has to offer (early to mid Feb was what all the analogs suggest is likely our most hostile period in terms of the longwave pattern) we are in pretty good shape.  

[Warm Nose]

17 minutes ago, psuhoffman said:

Good morning

Quick summary of what I see

The first threat Sunday is actually simple, but the cause for divergence across guidance is that its delicate.  There is a vigorous SW over western AK right now.  It's going to split over western Canada with a piece going east and merging into the TPV and another part diving into the trough, rounding the base and becoming our snow threat Sunday.  This energy activates the boundary.  It's pretty simple, how much energy and what track does this wave take.  But its delicate, its a relatively weak minor player in the overall flow so models will struggle with it, but this delicate weak piece of energy holds our fate wrt snowfall sunday.  

 

The next bigger threat involves major players on the hemispheric longwave scale, but it involves lots of them in a delicate intricate balancing act so its complicated.  

 

The main TPV (1 and 2) is going to elongate and eventually split.  How much energy resides with 1 and 2 and where 1 ends up and how quickly it clears out of the way to our north is a major factor.  How much energy trails with 2 and how it interacts with 3 is a major factor.  What 4 does and how it influences the tail of the trough is a factor.  And finally what the next major wave 5 does and whether if flattens or amplifies the downstream trough is a factor.  

There is no way guidance is going to lock all this in at this range, especially absent blocking to set firm guides in the flow for all these features.  But in general we want more energy to reside further west with 2 and 3 and less with 1 and that has been the trend across all guidance over the last 24 hours.  But don't expect this to be resolved quickly.  Even the crazy GFS idea of holding back so much energy that it becomes the next threat 48 hours later is not off the table and shows up on some individual members of the EPS.  

Lastly, what comes AFTER AFTER....

EPS continues to trend towards a much more friendly look for February.  It's already backing off on the crazy SER look it was suggesting.  It continues to trend towards lower heights near Hawaii which is a key, that look of the pac jet undercutting the WPO EPO ridge typically suggests troughs won't get stuck in the southwest and press east more.  It also pushes the WPO EPO ridge poleward and often leads to AO ridging over the top, which we are seeing more and more now on long range guidance.  This also helps to deepen troughs into the CONUS.  

This look puts a lot of pressure for the cold to press southeast.  Last nights op euro is a good example of what that pattern would actually look like because it matches the h5 of the EPS very closely. 

The SER is there at H5 but look at what it actually looks like where it matters

We are very much in the game for boundary waves in that look.  It's February and we don't need as much of a perfect pattern to get snow the first half of February as just about every other time of the year.  If that is the worst look this winter has to offer (early to mid Feb was what all the analogs suggest is likely our most hostile period in terms of the longwave pattern) we are in pretty good shape.  

tl;dr: ¯\_(ツ)_/¯

[yoda]

12z ICON is a quick hitter Sunday afternoon into the evening

[SomeguyfromTakomaPark]

2 minutes ago, yoda said:

12z ICON is a quick hitter Sunday afternoon into the evening

ICON is nice, accumulating daytime snow without temperature issues. 

[stormtracker]

43 minutes ago, wdrag said:

Thank you very much to you and Etta. The article had what I needed.  Regards, Walt

The man, the myth, the legend! Walt Drag! The OG posters know this man well.  

[yoda]

4 minutes ago, yoda said:

12z ICON is a quick hitter Sunday afternoon into the evening

1-3 for most... 2-4 Delmarva 

[stormtracker]

1 hour ago, Warm Nose said:

Current state of this sub

Wait, people are bailing today for mid week storm 7.5 days from now?  

[Paleocene]

Just now, stormtracker said:

Wait, people are bailing today for mid week storm 7.5 days from now?  

Everyone ignored bob and psu's posts that nothing will be resolved until within 96-72 hours.

[stormtracker]

1 minute ago, Paleocene said:

Everyone ignored bob and psu's posts that nothing will be resolved until within 96-72 hours.

So a normal day in the Mid Atlantic forum.  Gotcha. 

[yoda]

FWIW, which we all know isn't much... but 12z ICON says it's 4 degrees at DCA at 7am Tuesday with a DP of -10 

[yoda]

Yes, +SN in TAH and NO at 156 on the 12z ICON lulz

Freezing rain and 29 at KJAX at 162

[Maestrobjwa]

Just now, Paleocene said:

Everyone ignored bob and psu's posts that nothing will be resolved until within 96-72 hours.

Which is just what I thought was gonna happen, smh Some of y'all gotta chill and let it play out. If a run doesn't show what ya want, punt it and come back in 6-12 hours. I was afraid this was gonna happen especially after yesterday's weenie runs...and some of you have been doing this long enough to uh...know better? 

Yes we're all weenies and logic doesn't always work, but c'mon people...If you find yourself getting upset over one run--especially in a patern like this that's hard to nail down, just zoom out, take the broader view, and just move on to the next model run and go do something else and put your focus elsewhere 

[SomeguyfromTakomaPark]

ICON suppresses the midweek storm but as @psuhoffman pointed out yesterday it wouldn't take much to get a better solution.  That threat is definitely still on the table for us IMO.

[hstorm]

12 minutes ago, stormtracker said:

The man, the myth, the legend! Walt Drag! The OG posters know this man well.  

As a kid growing up in southern New England, Walt's AFDs were always a great and informative read (especially before an impending winter storm).

[clskinsfan]

Historic Charleston snowstorm on the ICON. IT has to be right. My son left the Shenandoah Valley this summer to live there so he didnt need to deal with snow anymore.

[Terpeast]

42 minutes ago, psuhoffman said:

Good morning

Quick summary of what I see

The first threat Sunday is actually simple, but the cause for divergence across guidance is that its delicate.  There is a vigorous SW over western AK right now.  It's going to split over western Canada with a piece going east and merging into the TPV and another part diving into the trough, rounding the base and becoming our snow threat Sunday.  This energy activates the boundary.  It's pretty simple, how much energy and what track does this wave take.  But its delicate, its a relatively weak minor player in the overall flow so models will struggle with it, but this delicate weak piece of energy holds our fate wrt snowfall sunday.  

 

The next bigger threat involves major players on the hemispheric longwave scale, but it involves lots of them in a delicate intricate balancing act so its complicated.  

 

The main TPV (1 and 2) is going to elongate and eventually split.  How much energy resides with 1 and 2 and where 1 ends up and how quickly it clears out of the way to our north is a major factor.  How much energy trails with 2 and how it interacts with 3 is a major factor.  What 4 does and how it influences the tail of the trough is a factor.  And finally what the next major wave 5 does and whether if flattens or amplifies the downstream trough is a factor.  

There is no way guidance is going to lock all this in at this range, especially absent blocking to set firm guides in the flow for all these features.  But in general we want more energy to reside further west with 2 and 3 and less with 1 and that has been the trend across all guidance over the last 24 hours.  But don't expect this to be resolved quickly.  Even the crazy GFS idea of holding back so much energy that it becomes the next threat 48 hours later is not off the table and shows up on some individual members of the EPS.  

Lastly, what comes AFTER AFTER....

EPS continues to trend towards a much more friendly look for February.  It's already backing off on the crazy SER look it was suggesting.  It continues to trend towards lower heights near Hawaii which is a key, that look of the pac jet undercutting the WPO EPO ridge typically suggests troughs won't get stuck in the southwest and press east more.  It also pushes the WPO EPO ridge poleward and often leads to AO ridging over the top, which we are seeing more and more now on long range guidance.  This also helps to deepen troughs into the CONUS.  

This look puts a lot of pressure for the cold to press southeast.  Last nights op euro is a good example of what that pattern would actually look like because it matches the h5 of the EPS very closely. 

The SER is there at H5 but look at what it actually looks like where it matters

We are very much in the game for boundary waves in that look.  It's February and we don't need as much of a perfect pattern to get snow the first half of February as just about every other time of the year.  If that is the worst look this winter has to offer (early to mid Feb was what all the analogs suggest is likely our most hostile period in terms of the longwave pattern) we are in pretty good shape.  

 

Excellent post. 

One thing I'm watching for wrt end of Jan into Feb is how the Alaska ridge evolves or trends. The GFS ensembles want to retrograde it SW to the Aleutians, causing the crazy warm SE ridge look. But the Euro ensembles have it split down the middle, 50% retrogrades it NW and makes a poleward ridging connection, keeping the cold across the CONUS. The other half is split between the GFS look and a compromise between the two (which is still "just cold enough" for us). The run-to-run trends are favorable so far, though. Definitely gonna keep an eye on this because it could open up more opportunities for a SECS/MECS in February.

[Buddy1987]

6 minutes ago, hstorm said:

As a kid growing up in southern New England, Walt's AFDs were always a great and informative read (especially before an impending winter storm).

F’n A! You got that right! Used to get me hype reading the detailed AFD’s. 

[stormtracker]

9 minutes ago, hstorm said:

As a kid growing up in southern New England, Walt's AFDs were always a great and informative read (especially before an impending winter storm).

Most of us have never lived up there and we would STILL enjoy reading his AFDs during east coast snowstorms. 

[stormtracker]

At my physical. When i refreshed this thread, i wanna see 2,541 new posts by 11:30

[peribonca]

It's going to be pretty amazing watching that radar blossom Friday evening over the central part of the country