December and a Hint of January Pattern Discussion

[Bob Chill]

Can't resist can you?

 

I've become a bitter weenie. 

 

NYE storm could have a 50/50 low. I have the laser out on this one. If it vaporizes then I'll start focusing on Feb. 

 

ETA:

 

Also has an east based -nao. Not an impressive -nao but definitely strong enough ridging to help. Models have been showing greenland ridging for a few days now in some form or another. Including the euro. 

[Fozz]

I've become a bitter weenie. 

 

You need to spend a weekend in Garrett county while they're getting an upslope event

[WxUSAF]

It's been unusually consistent so a signal for sure. Getting it to go underneath us will be a challenge but it will give us something to track until the pattern improves in mid Feb. 

GEFS are pretty supportive as well of a big storm in the eastern CONUS from 12/31-1/3 as well.  That's not really a super profound statement actually, but it shows the Op is really not out to lunch or isolated.  The pattern gets pretty quiet and northern stream dominated after the mega-torch this weekend for about 5-7 days, and then split flow signs start showing up and things get active again.  

[WxUSAF]

Today's GEFS super ensemble mean for D+11:

 

The 1960 date had a big rain event 2 days after the analog date…with a high temp at DCA of 35F on the day.  BWI that day only had a high of 33F and had even more precip.  Wunderground says 0.0" snow…not sure if that is right?  Either way, it sounds like a good analog to Wes's expectation of 40F and rain on New Year's Eve!

 

1989 had something similar but a bit warmer.  2009 had a little rain/snow mix on or about that date.  1998 had a solid (fairly mild) rain 2 days before the analog.  Same for 1962.    

[Ian]

Not until late February.

It can be an issue here by early feb with marginal temps. Actually it might still be an issue in DC now.

[Bob Chill]

Euro has a closed ull straddling the nm/mexico border d10 w/ precip breaking out in tx. Strong confluence overhead and to the north. 50/50 is there but not impressive. With all this being said, i'm sure it will find a way to cut. Or get all miller b and stuff. 

[WinterWxLuvr]

It can be an issue here by early feb with marginal temps. Actually it might still be an issue in DC now.

I've always thought above 35 degrees (angle) it becomes an issue.  That's pretty much pre-Halloween type sun angle around here. So yes, I agree with you.  By about the 10th of Feb it's quickly becoming an issue.

[NJwinter23]

Euro has a closed ull straddling the nm/mexico border d10 w/ precip breaking out in tx. Strong confluence overhead and to the north. 50/50 is there but not impressive. With all this being said, i'm sure it will find a way to cut. Or get all miller b and stuff. 

 

2nd run in a row its cutting off energy in the SW, and I'm guessing its the old bias coming into play

[Subtropics]

It can be an issue here by early feb with marginal temps. Actually it might still be an issue in DC now.

At our latitude the sun never really gets all that low. We still are recommended to wear sunscreen of at least SPF 15 year-round.

[WEATHER53]

Situation setting up as super wintery late month. Analogs say so and they have been right on so far and reliable Mongolian High Preswsure in the game also.

[usedtobe]

Today's GEFS super ensemble mean for D+11:

 

The 1960 date had a big rain event 2 days after the analog date…with a high temp at DCA of 35F on the day.  BWI that day only had a high of 33F and had even more precip.  Wunderground says 0.0" snow…not sure if that is right?  Either way, it sounds like a good analog to Wes's expectation of 40F and rain on New Year's Eve!

 

1989 had something similar but a bit warmer.  2009 had a little rain/snow mix on or about that date.  1998 had a solid (fairly mild) rain 2 days before the analog.  Same for 1962.    

I was just kidding about a 40 degree rain event.  I think that or a mix would be the likely scenario for any storm towards the end of Dec.   The superens analogs have not been pretty in that regard for several days.

[WxUSAF]

I was just kidding about a 40 degree rain event.  I think that or a mix would be the likely scenario for any storm towards the end of Dec.   The superens analogs have not been pretty in that regard for several days.

Well, given that 2 of the analogs had something pretty similar, I think something like that is certainly on the playing field.  I actually wonder if anyone has confirmation that the late December 1960 event was all rain?  Seeing that BWI had a high of 33F (and a low in the 20s) and Wunderground says no snow with 0.75"+ of precip, I'm curious whether that was actually a rain/snow mix, all rain, all snow, etc…  Certainly something with a gradient across that sub-region that (unfortunately) probably screws you, modestly rewards me and crushes Mount Parkton and Winchester might be reasonable given the pattern.

[Ian]

I've always thought above 35 degrees (angle) it becomes an issue.  That's pretty much pre-Halloween type sun angle around here. So yes, I agree with you.  By about the 10th of Feb it's quickly becoming an issue.

Definitely not our biggest worry of late. We need snow before being too concerned.  And we tend to get our big snow in that timeframe (Jan 15-Feb 15) anyway).  After Feb 15 I worry more.. I still don't believe in March snow in the city even after last yr. 

[Fozz]

Well, given that 2 of the analogs had something pretty similar, I think something like that is certainly on the playing field.  I actually wonder if anyone has confirmation that the late December 1960 event was all rain?  Seeing that BWI had a high of 33F (and a low in the 20s) and Wunderground says no snow with 0.75"+ of precip, I'm curious whether that was actually a rain/snow mix, all rain, all snow, etc…  Certainly something with a gradient across that sub-region that (unfortunately) probably screws you, modestly rewards me and crushes Mount Parkton and Winchester might be reasonable given the pattern.

 

I'm guessing a wintry mix or ice storm. BWI received 0.84" of precip and 1.4" of snow/sleet in that event (check the Utah Climate site, so much data there!). Parkton and Westminster didn't get much snow either. 

[usedtobe]

Well, given that 2 of the analogs had something pretty similar, I think something like that is certainly on the playing field.  I actually wonder if anyone has confirmation that the late December 1960 event was all rain?  Seeing that BWI had a high of 33F (and a low in the 20s) and Wunderground says no snow with 0.75"+ of precip, I'm curious whether that was actually a rain/snow mix, all rain, all snow, etc…  Certainly something with a gradient across that sub-region that (unfortunately) probably screws you, modestly rewards me and crushes Mount Parkton and Winchester might be reasonable given the pattern.

I reread what I wrote and really meant a mix or rain event.

[Yeoman]

Situation setting up as super wintery late month. Analogs say so and they have been right on so far and reliable Mongolian High Preswsure in the game also.

 

I'd feel better with that high closer to Kazakhstan.. 

 

I'm still liking the 1/28 - 2/2 period because I'll be in Cali

[Bob Chill]

18z gfs is pretty whacky in the long range. Models are having a tough time figuring out where we go after the scorched earth this weekend. 

 

-EPO is probably going to reload in some fashion. That's good. How much cold it could deliver isn't worth worrying about much.

 

Boring weather on tap for the balance of next week. NS dominated pattern with fronts and progression. 

 

I've seen enough signs at some blocking showing up to think that it may be the next move as we close out dec and move into jan. 

[clskinsfan]

18z gfs is pretty whacky in the long range. Models are having a tough time figuring out where we go after the scorched earth this weekend. 

 

-EPO is probably going to reload in some fashion. That's good. How much cold it could deliver isn't worth worrying about much.

 

Boring weather on tap for the balance of next week. NS dominated pattern with fronts and progression. 

 

I've seen enough signs at some blocking showing up to think that it may be the next move as we close out dec and move into jan. 

 

There was a decent clipper in the long range. But it is in the long range afterall

[CAPE]

At our latitude the sun never really gets all that low. We still are recommended to wear sunscreen of at least SPF 15 year-round.

Lol at the sun angle concerns already. Yeah its a problem in late Feb, mid afternoon with marginal BL temps, when for some reason we expect precip rates to save the day. Snow doesnt exactly accumulate efficiently at night either when its 33 or 34 degrees. When we have bonafide cold, and a real storm, sun angle is a non issue. Most of the historic blizzards in this area occur in mid to late February. When the sun comes out the next day, unless temps are well below freezing, yup the snow melts. That happens whether its Jan 1 or March 1.

[Scarlet Pimpernel]

Lol at the sun angle concerns already. Yeah its a problem in late Feb, mid afternoon with marginal BL temps, when for some reason we expect precip rates to save the day. Snow doesnt exactly accumulate efficiently at night either when its 33 or 34 degrees. When we have bonafide cold, and a real storm, sun angle is a non issue. Most of the historic blizzards in this area occur in mid to late February. When the sun comes out the next day, unless temps are well below freezing, yup the snow melts. That happens whether its Jan 1 or March 1.

 

As you say, toward late February that can become an issue if temperatures are marginal.  This past March is a case in point of how things can fail.  If you've got a good storm, with decent or better cold air, it's not really much of an issue.  That's true into early March I think, though of course we require more abnormal cold as you get into March (February, perhaps not quite so much).  The moderate event we got on March 1-2, 2009 (~5-6"), it was below freezing for max temps at DCA for two straight days, including the day after the storm...pretty impressive for the beginning of March!  And of course it was in the teens and low 20s throughout the PD-II storm in 2003, on Feb. 16-17.  But you need the right set-up and delivery of cold air, which I guess is true no matter when it is!

 

Someone once told me that you can have a reasonable hope at still getting some snow up to about the Ides of March in the DC area (not necessarily a lot, but measurable).  My experience tells me that's generally a good estimate, but again depends on the pattern and things like that, and certainly not every year.  Perhaps more like early March for having a good shot at a "good" event is about the limit.

[Bob Chill]

There was a decent clipper in the long range. But it is in the long range afterall

Still a signal for nye timefrane. Could easily be a bigger storm with gulf connection too or nothing at all. A clipper with a good vort pass is the best shot at all snow imo even if it's small. We need an awful lot of luck to go all snow with a bigger event. Like you said, it's lr. Specifics at this range is silly but it's not a get excited pattern.

I think we go cold again across the conus or at least a good portion before we close the month. It would make sense. Models underestimated the last epo so if we're going back in that direction I think we'll see another decent arctic dump sooner rather than later.

My weenie eyes are more focused on getting the pv in Canada displaced wirh some blocking. There are hints...

[CAPE]

As you say, toward late February that can become an issue if temperatures are marginal.  This past March is a case in point of how things can fail.  If you've got a good storm, with decent or better cold air, it's not really much of an issue.  That's true into early March I think, though of course we require more abnormal cold as you get into March (February, perhaps not quite so much).  The moderate event we got on March 1-2, 2009 (~5-6"), it was below freezing for max temps at DCA for two straight days, including the day after the storm...pretty impressive for the beginning of March!  And of course it was in the teens and low 20s throughout the PD-II storm in 2003, on Feb. 16-17.  But you need the right set-up and delivery of cold air, which I guess is true no matter when it is!

Yes. Funny I was just thinking about that March 09 event. Great example. Bitter cold for 2 or 3 days after, and little melting.

[CAPE]

Still a signal for nye timefrane. Could easily be a bigger storm with gulf connection too or nothing at all. A clipper with a good vort pass is the best shot at all snow imo even if it's small. We need an awful lot of luck to go all snow with a bigger event. Like you said, it's lr. Specifics at this range is silly but it's not a get excited pattern.

I think we go cold again across the conus or at least a good portion before we close the month. It would make sense. Models underestimated the last epo so if we're going back in that direction I think we'll see another decent arctic dump sooner rather than later.

My weenie eyes are more focused on getting the pv in Canada displaced wirh some blocking. There are hints...

Some spread, but looks somewhat promising.... http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

[Bob Chill]

Wow, holy -epo reload with the 18z gefs. 500 height anoms say bring on the hounds. Starts out west first bit this is definitely the first run showing another outbreak before we close the month. Outlier or trendsetter?

[midatlanticweather]

We know it is the trend. Just may be one of disappointment!!

[Scarlet Pimpernel]

My weenie eyes are more focused on getting the pv in Canada displaced wirh some blocking. There are hints...

 

Mine too, if they're not too deceived (I did have to get glasses recently, you know)!  Maybe it's the Christmas season making me see that, and maybe it's the 18Z happy hour run.  It's not all that great, but I've seen the GFS try to nose in some kind of ridging over Greenland the past couple or so days, even slightly.  And the 18Z sure tries to build a hell of a lot of ridging in the eastern Pacific, though I'm not so sure I like that exact location (tad too west?).  It's gone back and forth on that to an extent as well.

 

EDIT:  When it gets in range to show up on the 84-h NAM, I'm all in!!!

[aldie 22]

I always forget that every winter it usually snows every day and the temps never get above 32 until late march...

[WinterWxLuvr]

I always forget that every winter it usually snows every day and the temps never get above 32 until late march...

I keep waiting for that pattern change. The last month has been torture.

Funny thing is, that pattern change so many are after might come. 89-90 style! Any takers?

[snow.]

I keep waiting for that pattern change. The last month has been torture.

Funny thing is, that pattern change so many are after might come. 89-90 style! Any takers?

 

this december is a lot like 1989...will end up only around 13 degrees warmer

[WinterWxLuvr]

this december is a lot like 1989...will end up only around 13 degrees warmer

That was a brutal month. The flip was brutal too. Still have nightmares about that one.