February Mid/Long Range Discussion

[showmethesnow]

14 minutes ago, C.A.P.E. said:

True, but in a Nina a stout west-based block might prove to be the difference it getting multiple moderate frozen events vs what we are experiencing now. Bad tracks when we get something decently juiced up, and otherwise separate streams with NS dominance, fast flow, and weak sauce ss waves, with our area often stuck in no mans land.

Trying to remember the details from looking at in the fall but I believe during a La Nina the best combo for snow by a good margin was a -AO and a central or west based -NAO to slow the flow. Think an east based -NAO wasn't too bad as well either. But that is sort of a DUH comment considering that that combo (-AO/-NAO) works well in any ENSO state. But if I were only able to pick one or the other I would go with the -AO per the information Bob had provided. He made a very strong case in that regard.

[Bob Chill]

58 minutes ago, showmethesnow said:

Trying to remember the details from looking at in the fall but I believe during a La Nina the best combo for snow by a good margin was a -AO and a central or west based -NAO to slow the flow. Think an east based -NAO wasn't too bad as well either. But that is sort of a DUH comment considering that that combo (-AO/-NAO) works well in any ENSO state. But if I were only able to pick one or the other I would go with the -AO per the information Bob had provided. He made a very strong case in that regard.

I'd love a -nao. No doubt there but if I had to choose between the 2 it would be the ao every time. The early Dec event had a -ao and other brief periods of a -ao coincided with other minor snowfalls. I think the ao was neg during the coastal bomb. 

The thing about the -ao is it helps with a lot of things with mid latitude flow and hp position. A neg nao is a big storm producer. Especially phase changes. But just combing cold with even modest precip, the ao really gets the job done in our area. 

I'm cautiously optimistic right now. The strat could be just the ticket to get a stable -ao going for more than 15 minutes. Lol. If the ao goes neg near mid month and holds then the landscape for winter storms really changes here. West tracks become difficult and elongated cold hp to the north are favored. Luck is always required but we need less luck with a stable -ao. 

[cae]

6 hours ago, dallen7908 said:

EPS gives little hope over the next 15 days with mean snow fall totals in DC of 0.5/1/1.5" over next 5/10/15 days.  The percent change of >1" is 18/26/26% while the percent chance of 6" is 2/4/4%. Much better chances of a >1" snow due north of DC at MD/PA border where chances are 82/90/94%.  Odds of 6" snow there are 10/12/14%.  Much better chances central PA north where the EPS odds of >6" during the next 15 days is ~90%. 

Nice summary, thanks.  Thanks for also mentioning how close the snow is, as I think there's a difference between having a low snowfall mean with no snow nearby and a low snowfall mean with someone getting crushed nearby.  Looking at the 18z GFS / 12z GGEM, both give DC less than 0.1" qpf as snow in the next 8 days, but central PA just north of us gets over 2" liquid equivalent.  The coming pattern favors northern / elevated regions, but it wouldn't take much of a shift to give the cities some chances.

[stormtracker]

3 hours ago, showmethesnow said:

Not a big fan of the off runs of the GEFS but the 18z made a pretty good positive move for the Wed. storm. High to our north is a little stronger, low is a little weaker and is tracking a little farther to the south. GEFS mean shows the effect of the changes well.

 

Maybe luck will be on our side and things will start trending our way.

 

Nevermind.

[Ji]

Gfs south again. By Monday....it will be a secs. For Norfolk

[Climate175]

That's a La-Nina February for ya.

[psuhoffman]

4 hours ago, Bob Chill said:

I'd love a -nao. No doubt there but if I had to choose between the 2 it would be the ao every time. The early Dec event had a -ao and other brief periods of a -ao coincided with other minor snowfalls. I think the ao was neg during the coastal bomb. 

The thing about the -ao is it helps with a lot of things with mid latitude flow and hp position. A neg nao is a big storm producer. Especially phase changes. But just combing cold with even modest precip, the ao really gets the job done in our area. 

I'm cautiously optimistic right now. The strat could be just the ticket to get a stable -ao going for more than 15 minutes. Lol. If the ao goes neg near mid month and holds then the landscape for winter storms really changes here. West tracks become difficult and elongated cold hp to the north are favored. Luck is always required but we need less luck with a stable -ao. 

There is a lot of crossover with ao and nao. And I only looked at 4"+ events. There were a lot of 1-3" snows without a -nao. I would have to look at the AO. And under all base states the AO is king. But the sheer lack of warning level events without a -nao in a Nina is pretty compelling evidence that under a Nina the nao is a necessary ally. The largest snow at bwi without a -nao was 4" and that only happened twice.  There have been no warning criteria snows without nao help in the last 20 ninas  

I should look and see if all the warning snows also had a -ao.  It's possible that the Nina base state requires both to overcome.  But I can see logically why the progressive NS in a Nina would require the nao more.  During times of split flow or a stronger stj or less progressive NS the AO alone can work.  Just suppress the jet and get cold further south and we have a good chance in other patterns.  But in this one getting a block upstream to buckle the jet and force the damn NS to slow and dig would be necessary  

All this is about warning level.  We have and can get 1-4" snows without a -nao.  And I will gladly take every flake.  I'm not turning down some more advisory level events.  But let's be honest unless we get one warning level even most will mark this season as a failure.  

 

[Jebman]

7 hours ago, showmethesnow said:

Not a big fan of the off runs of the GEFS but the 18z made a pretty good positive move for the Wed. storm. High to our north is a little stronger, low is a little weaker and is tracking a little farther to the south. GEFS mean shows the effect of the changes well.

 

This would help the western crew. They need the snow a LOT more than I do.

[AfewUniversesBelowNormal]

Pretty nasty pattern setting up, could be some record breaking warmth. 

[CAPE]

NH pattern looks pretty similar now on the EPS and GEFS in the LR. Actually the EPS has baby-stepped its way to maybe even a bit better look than the GEFS, comparing the latest 0z runs. EPS is now more impressive with potential ridging over GL towards the end of the run. Not a super cold look, but probably good enough especially if we can get a block to continue developing and build a bit further south. Relatively warm in western and central Canada with the h5 look in the panel below, but our temps would be mostly average to slightly below. Not great considering it will be mid-late Feb, but as long as the Pac does not turn hostile, and with a bit of blocking, we should see increased chances of storms tracking to our south, rather than right over us or to the NW as we have now. All subject to change of course.

[rcflyermd68]

well its good to see the  gfs  is giving  us  increased  storminess  and precipitation which we so badly need, the fact it isnt snow is unfortunate, but i,m not going to complain.  Have a  good day all.

[showmethesnow]

Still am thinking that we can't sit on the possible Wed. storm. Seeing continued improvement on most models with a weaker southern storm and the track adjusting accordingly south. Which makes sense because the models have quite often overplayed them initially. Higher pressures are to the north which should help lock in the cold a little longer for WAA (warm air aloft) induced snows. Temps have continually adjusted south for the most part and the snowfall means have as well. Only another 50 miles or so southerly shift from getting the cities in on some half decent snowfall.

[BristowWx]

3 minutes ago, showmethesnow said:

Still am thinking that we can't sit on the possible Wed. storm. Seeing continued improvement on most models with a weaker southern storm and the track adjusting accordingly south. Which makes sense because the models have quite often overplayed them initially. Higher pressures are to the north which should help lock in the cold a little longer for WAA (warm air aloft) induced snows. Temps have continually adjusted south for the most part and the snowfall means have as well. Only another 50 miles or so southerly shift from getting the cities in on some half decent snowfall.

I was thinking that too until I saw 6z which I thought was a step back with being more amped and warmer.  

[CAPE]

18 minutes ago, showmethesnow said:

Still am thinking that we can't sit on the possible Wed. storm. Seeing continued improvement on most models with a weaker southern storm and the track adjusting accordingly south. Which makes sense because the models have quite often overplayed them initially. Higher pressures are to the north which should help lock in the cold a little longer for WAA (warm air aloft) induced snows. Temps have continually adjusted south for the most part and the snowfall means have as well. Only another 50 miles or so southerly shift from getting the cities in on some half decent snowfall.

Yeah I am casually watching it. For here anyway, I think the best chance of frozen is on the tail end, as the colder air comes in. As usual the question becomes how fast the cold gets in and is there any moisture left when it does? Answer to that is almost always no lol.

[AfewUniversesBelowNormal]

It's building into a pretty impressive storm. There is a -250dm height anomaly north of Hawaii right now, +PNA, somewhat unexpectedly. This may skew things colder for the 8th

[Wonderdog]

On Valentine's Day, another storm approaches us when the Southwest and we have a high pressure to the north of us but still rain for us. Maybe we can get some changes

[Ralph Wiggum]

On Valentine's Day, another storm approaches us when the Southwest and we have a high pressure to the north of us but still rain for us. Maybe we can get some changes

Watch that Feb 10-16 period for some roller coaster surprises. Pattern screams for something.....Im picturing a modest warm ridge getting squashed via a progressive and potent NS disturbance and a wave or 2 developing along the old frontal boundary after the cold has funnelled back into the region. Whether those followup waves get squashed thanks to the NS or the SER comes to the rescue setting up a battleground is tbd but Ive been keying on this time frame for something for a while now. Starting to see hints on ops and ens now as well.

 

[showmethesnow]

7 minutes ago, Ralph Wiggum said:

Watch that Feb 10-16 period for some roller coaster surprises. Pattern screams for something.....Im picturing a modest warm ridge getting squashed via a progressive and potent NS disturbance and a wave or 2 developing along the old frontal boundary after the cold has funnelled back into the region. Whether those followup waves get squashed thanks to the NS or the SER comes to the rescue setting up a battleground is tbd but Ive been keying on this time frame for something for a while now. Starting to see hints on ops and ens now as well.

 

Have liked the next weekend time period for a possible storm for a couple of days now. Partially from what I have seen on the models and partially just gut feeling. 

[stormtracker]

18 hours ago, Ji said:

Gfs so close midweek

That didn't last long.

[BristowWx]

6 minutes ago, stormtracker said:

That didn't last long.

Next weekend not looking so great either.  Starting to think this won’t be a good winter.  

[clueless]

TT out to 168.  That’s enough for me.  

[87storms]

wednesday doesn't look impossible.  maybe it will end up a better version of today.  we do need a south trend, though.

[87storms]

next weekend looks ugly though.  rainer up and down the coast, though i guess that's what happens when the low is in upper michigan lol.  i don't know what that's all about, but it's a cutter of the chicago/detroit variety.

[Ji]

Have liked the next weekend time period for a possible storm for a couple of days now. Partially from what I have seen on the models and partially just gut feeling. 

Looks horrible. Next.....

[Ji]

wednesday doesn't look impossible.  maybe it will end up a better version of today.  we do need a south trend, though.

The south trend ended yesterday when we needed it to keep going. It's over. This joke today is probably our last winter storm for a long time

[87storms]

5 minutes ago, Ji said:

9 minutes ago, 87storms said:

wednesday doesn't look impossible.  maybe it will end up a better version of today.  we do need a south trend, though.

The south trend ended yesterday when we needed it to keep going. It's over. This joke today is probably our last winter storm for a long time

need something the following week or we might be in trouble.  sort of running out of time unless we're aiming for late season heroics.

[BristowWx]

1 minute ago, Ji said:

5 minutes ago, 87storms said:

wednesday doesn't look impossible.  maybe it will end up a better version of today.  we do need a south trend, though.

The south trend ended yesterday when we needed it to keep going. It's over. This joke today is probably our last winter storm for a long time

Totally agree.  Even in my crappy location I can usually do better than 15 minutes of snow and 30 minutes of sleet.  

[Conway7305]

If we’re going to get any legit storm chances  it won’t be until later Feb and early March. La Niña winter isn’t helping.  NAO still positive and AO positive. Several AO members look to negative by end of Feb.  NAO potentially goes neutral or hopefully negative late month (of course those oscillation points always change).  MJO looks to be stuck in phase 7 till towards end of Feb then hopefully move into phase 8.  

[BristowWx]

4 minutes ago, Conway7305 said:

If we’re going to get any legit storm chances  it won’t be until later Feb and early March. La Niña winter isn’t helping.  NAO still positive and AO positive. Several AO members look to negative by end of Feb.  NAO potentially goes neutral or hopefully negative late month (of course those oscillation points always change).  MJO looks to be stuck in phase 7 till towards end of Feb then hopefully move into phase 8.  

Yeah PD weekend is flaming at 850 this op run so if that holds we will be thinking gardening vice shoveling.  Maybe we get one solid week of winter last week of Feb.  

[poolz1]

Idk, no real south trend at 12z but the trend of having the high to our north instead of off the coast of NE continued.  Just need a little more CAD for a good front end thump.  If that high is real and we can time things, models should start to pick up on the better thump idea even though the slp track may remain the same.

Eta: