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Posted at 1:15 PM ET, 12/23/2010

Odds of major storm shrinking. Any snow at all?

By Wes Junker

Over the last several days, a rather fuzzy Snow Lover's Crystal Ball has discussed how one weather model was forecasting a major winter storm for the D.C. area Sunday into Monday, while all of the others were predicting a glancing blow or a near miss. Today, the crystal ball is clearing up. The odds of getting a major storm have diminished - it's looking more and more like the storm will be a glancing blow or a near miss.

Next accumulating snow chance: Saturday into Monday
Probability of accumulating snow (1" or more): 30-40%
Probability of more than 4": 10-15%

Keep reading for the technical discussion...

TECHNICAL DISCUSSION

Essentially the forecast now has two scenarios. The storm's low-pressure center will track far enough east to give us only light snow, with the low then possibly hooking left to hit parts of eastern New England. Or, the storm will stay and develop far enough east to miss us altogether. There still is uncertainty about when the snow will arrive and end if we get any. Some models are suggesting a chance of light snow (maybe a dusting or so) for Christmas while others are suggesting that any snow would fall mainly on Sunday.

Eastern New England is another story. The threat of a major snowstorm with wind-driven snow is much higher for Cape Cod than here. Travelers heading toward or away from eastern New England, especially Cape Cod, need to monitor the local forecast for updated information about the storm, as only minor changes in storm track could lead to large differences in snow totals.

Why has the big-storm scenario almost fallen off the table for the D.C. area? After a few runs that consistently showed the potential for heavy snow here, the European model shifted significantly eastward in its position of the low and associated precipitation shield on last night's run and this morning's as well, which has just come out. Yesterday morning's run had a monster storm tucked right along the coast (see below, left), giving the D.C. area on the order of 15-20 inches of snow. Last night's run (below, right) moved the low east, yielding only about an inch of snow for our area.


European model forecast position of storm's low-pressure center from yesterday morning's (left) and yesterday evening's (right) model runs. Credit: Penn State University.

Last night's European track forecast is very close to those shown by the model's ensemble mean, which we showed yesterday, and is similar to that of the other operational models. The UKMET, Canadian, both night runs of the GFS, and NAM all have out-to-sea solutions. Where they differ is what will happen over eastern New England, with the NAM hinting at a near miss but the Euro and GFS suggesting that areas like Cape Cod could get hammered. The latest GFS from this morning looked a little less threatening for that area. Overall, the forecast for New England is far from certain as the models still could shift.


Probability of getting 0.10" or more of liquid equivalent (approx. 1" of snow) for the 24-hr period ending at 7 a.m. Monday based on the distribution of ensemble members. The scale is on the left. Credit: Penn State University.

Our reason for lowering to 30-40% the probability of the storm producing an inch or more of snow in the D.C. area is based on a compromise between two differing sets of ensemble guidance - the last two GEFS ensemble runs, which both show the probability of an inch being 50% (see right), and the SREF ensembles (not shown), which suggest there is little chance of any accumulating snow. Remember that ensembles are multiple runs of the model using a lower resolution with the initial conditions changed slightly.

The SREF ensembles have a higher resolution and more sophisticated differences between the member perturbations (changes in initial conditions or tweaks to the model physics). This more bearish grouping should probably be given more weight. But this early in the game, I'd rather lower the probabilities slowly rather than drop them more substantially only to have to raise them again if the models decide to shift back west. Besides, this morning's GFS run does give us the chance of a dusting on Christmas Day.

A storm that looked so tantalizing in some of the early model projections is now looking like a major disappointment for snow lovers. It's never over until verification, but the picture right now looks bleak for serious snow, though better for travel, at least locally.

By Wes Junker  | December 23, 2010; 1:15 PM ET
Categories:  Latest, Snow Lover's Crystal Ball, Winter Storms  
Save & Share:  Send E-mail   Facebook   Twitter   Digg   Yahoo Buzz   Del.icio.us   StumbleUpon   Technorati   Google Buzz   Previous: The National Christmas Tree with snow
Next: PM Update: Winds to reluctantly relent

Comments

Wes, thanks for the insightful analysis

Posted by: TGT11 | December 23, 2010 1:26 PM | Report abuse

Yes, it's the all too common (for the Washington area) dashing of hope a couple of days before the storm was supposed to hit. I fall for it every time. You would think I would learn not to get my hopes up. I guess having such an awesome winter last year, with almost every storm overperforming, made me forget our long history of disappointments. Sigh.

Posted by: scienceteacher3 | December 23, 2010 1:29 PM | Report abuse

I totally agree science teacher3 last year was amazing.... Is there a chance that it could swing back in the snowy favor? CWG, could you answer this in the comment section?

Please reply,
SnowDreamer

Posted by: SnowDreamer | December 23, 2010 1:35 PM | Report abuse

@scienceteacher3,

You took the words right out of my mouth.

Posted by: Rcmorgan | December 23, 2010 1:37 PM | Report abuse

Bummer. I had a personal day just burning a hole in my paycheck. . . .would have loved to spend Monday sledding with all the offspring and trying out the new snowball molder that santa is purportedly bringing my 9 year old son.

Posted by: BadMommy1 | December 23, 2010 1:38 PM | Report abuse

Good analysis, but it makes me very sad. Maybe it's all my fault for complaining too loudly last February when we didn't get a plow for 3 and 1/2 days. January looks to be warm and wet. What a disappointment.

Posted by: biketraveller22 | December 23, 2010 1:40 PM | Report abuse

Thanks Wes. It's interesting that the ECMWF, which has a reputation as the best medium rage model, was outperformed by the GFS and all the other models as well on this potential event. It looks like we have little chance of any significant winter storms for awhile. Time to enjoy the upcoming holiday week without the threat of weather disruption.

Posted by: ronbcust | December 23, 2010 1:42 PM | Report abuse

What does the 12z ECMWF look like? I can't seem to be able to find anywhere that releases it less than six hours after it runs...

Posted by: cleombrota | December 23, 2010 1:45 PM | Report abuse

I'm glad there's not a "dislike" option for this post (not for the analysis but for the outcome)...

Posted by: Jason-CapitalWeatherGang | December 23, 2010 1:46 PM | Report abuse

Perhaps what I really wanted for Christmas was a blizzard as crazy as that is. Heck I would have happily settled for a few inches of snow. But in the words of the Rolling Stones "You can't always get what you want."

Well, at least a few of us will be happy.

Posted by: Rcmorgan | December 23, 2010 1:46 PM | Report abuse

Why oh why can't everyone EXPLAIN the whys of weather forecasting like this. You'd get far fewer people screaming about "wrong" forecasts.

Posted by: AdmiralX | December 23, 2010 1:47 PM | Report abuse

@cleombrota

The Euro is a miss...except for southern New England

Posted by: Jason-CapitalWeatherGang | December 23, 2010 1:47 PM | Report abuse

ronbcust, the Euro has a noted bias of holding back/making too strong southern energy. I don't know if that's the case here but it sure looks like it. The blizzard runs all kept the southern energy slower than the rest of the models which allowed the rest to come together right for this area. Since that piece was fully sampled yesterday it seems everything got faster including the Euro. The run that just came out was even worse than last night if you like snow... Incredible changes though for sure.. 15-20" in DC and south for 3 runs in a row then almost nothing to nothing in the two following!

Posted by: Ian-CapitalWeatherGang | December 23, 2010 1:48 PM | Report abuse

The threat seems to be over for anything significant since the 12z Euro has now shifted eastward, unless a very unlikely shift back to the coast occurs.

I always had misgivings about the potential, stated in this forum as early as Monday night at 8:58. The very strong and large low pressure in the north Atlantic,no high pressure ridged from northern New England to the Lakes, instead we had a high pressure ridge extending south from the northern plains that could actually nudge the system a little east, especially without total phasing and the strong lp in the north Atlantic tending to shift a surface system offshore.

Wes, in your expert opinion, can we learn anything about the Euro from it's seeming total bust??, after screamimg major snowstorm for much of the east coast for several runs, while the GFS and other models were saying, not so fast! The Euro has gained much credibility in recent years. What happened??

Posted by: AugustaJim | December 23, 2010 1:50 PM | Report abuse

Augusta Jim,

I think we can learn quite a bit, any time a model is out on of the envelope of the other operational models and has a lack of support support from its ensembles, it should be viewed skeptically. That's what we tried to do.

Also, it looks the Euro may have a bias that crops up in cases when the pattern is amplifying and it then over-deepens the trough which also usually slows them down. The bias seems to be worse this year. The main thing I guess to take from it is though the euro is a good model, all models sometimes have problems.
That's the beauty of using ensembles to sort through the various possibilities.

Posted by: wjunker | December 23, 2010 1:59 PM | Report abuse

Still looking for help on driving to Atlanta on Christmas Day ... Would it be better to drive on Rt. 29 to I-85 or head west and drive on I-81 t0 I-75?

Posted by: txnva | December 23, 2010 2:01 PM | Report abuse

boooooo! hissssss! booooooo!

Posted by: walter-in-fallschurch | December 23, 2010 2:03 PM | Report abuse

@cleombrota on ECMWF access:

The ECMWF (unlike the GFS and other models, which are in the public domain) is proprietary and copyrighted. Nonetheless, a limited amount of output from the model has been publicly released through both the ECMWF and various sites. Companies can pay for faster and more complete ECMWF data sets. I would think that NCEP also gets to see more and sooner.

The Penn state site is the best free access I've found for individuals.

Posted by: ronbcust | December 23, 2010 2:04 PM | Report abuse

the really really bad news is i hear this might be the beginning of a warming trend? true? if so, that's horrible news. whereas lately every precip threat has been a snow threat, if it warms we're stuck w/dumb old rain...

Posted by: walter-in-fallschurch | December 23, 2010 2:08 PM | Report abuse

Silly question. In terms of ET, when is 0z, 12z, and 24z. Accuweather Pro has the Euro model, but still shows the 0Z run. Sounds unlikely that we'll see anything out of this now...maybe we'll get lucky and see some light snow out ahead on Christmas? At any rate, I have a feeling even Bastardi will be changing his thoughts by tonight. Last winter definitely spoiled us!

Posted by: DLO1975 | December 23, 2010 2:10 PM | Report abuse

A big dump in New England would be easy for them to deal with. But what about the South? I'm heading to NC and I understand that they could get snow there. Since they spend a small fraction of what New England spends on snow removal, a little snow there is a big deal. Can you tell us what to expect on I-95 South?

Posted by: mmcnamara | December 23, 2010 2:20 PM | Report abuse

@DLO1975 -

It depends on whether you're talking EST or EDT. EST = GMT-0500; EDT = GMT-0400. So:

00Z = 1900 (7pm) EST or 2000 (8pm) EDT on the day before
06Z = 0100 (1am) EST or 0200 (2am) EDT
12Z = 0700 (7am) EST or 0800 (8am) EDT; and
18Z = 1300 (1pm) EST or 1400 (2pm) EDT.

Hope that helps!

Posted by: mheney | December 23, 2010 2:22 PM | Report abuse

Walter:
The warming later next week will likely be temporary. There should be other threats as we move into and through January.

Remember, the last three weeks have been quite cold, but relatively dry, as northwest flow has been rather strong, surface and aloft.

A change in the pattern will be good, at least for a while.

Posted by: AugustaJim | December 23, 2010 2:26 PM | Report abuse

Personally I think it's still too close to make a definitive call that we're not going to get significant snowfall. It won't take very much for the models to do another shift and bring a significant amount of snowfall to our area. My guess is that as the storm approaches, we're going to see a trend towards higher accumulations. Maybe not the monster 20" totals, but that "Probability of more than 4": 10-15%" still leaves us with some uncertainty. Anxious to see what tonights model runs look like.

Posted by: SteveinAtown | December 23, 2010 2:26 PM | Report abuse

0z suite comes out between about 9 p.m. and 1:30 a.m. (1 hr later in EDT) (NAM ~9, GFS ~10, (other global), EURO ~1), so they run based off 0z data but don't show up for a bit after. 12z come out same times 12 hrs later. The Euro is probably just now hitting many sites tho don't know Accu's schedule. There is a freebie site you can make your own Euro maps pretty close after they come out at 1a/p but it's too involved to get into here. The precip stuff is all locked up unless you pay.

Posted by: Ian-CapitalWeatherGang | December 23, 2010 2:29 PM | Report abuse

Personally, I am happy that there is no snow storm in our near future. I had enough snow last winter to last a lifetime.

Posted by: david_in_stafford | December 23, 2010 2:35 PM | Report abuse

mmcnamara, below is a site you can click on get a feel for the timing of any rain or snow that may fall as you drive south. 00Z Sunday would be 7PM Saturday evening, 06Z sunday would be 1AM Sunday and 12Z would be 7AM Sunday.

http://coolwx.com/cgi-bin/getptype.cgi?region=us&model=gfs&run=12&fhr=24&field=ptype

Posted by: wjunker | December 23, 2010 2:37 PM | Report abuse

Shame to me for drinking the kool aid on this storm. Last winter (unlike all prior winters) was amazing in that even 4-5 days out, CWG was able to telegraph a consistent and generally increasing probability message its coming 50% chance...its still coming 60%...still coming 80%... and the vast majority of the time they were right.

Contrast that to the several prior winters where the message 4-5 days out was "maybe, maybe not...maybe, maybe not..." in these cases, it was best not to rely on anything since storms do often fail to come together at the last minute.

Still, this time around, I got suckered in by that 50% chance 5+ days out - reminded me of last winter, and I thought "oh man, here we go again". Not blaming you guys CWG - you call it like you see it, and obviously it looked good early in the week. Still, as the week wore on, and I didnt see the chances being upped, I should have known we are back to usual winters around here in Washington.

Posted by: SJ43560 | December 23, 2010 2:45 PM | Report abuse

Accuweather is saying the GFS run shifted to a big storm while the euro is still showing bomb of the decade. Their post is less than an hour after yours. Was there another GFS run?
http://www.accuweather.com/blogs/meteomadness/story/43380/euro-and-gfs-both-go-to-the-big-storm.asp

Posted by: jca-CrystalCity | December 23, 2010 2:49 PM | Report abuse

@SJ43560

The fact that we never could appreciably increase the odds wasn't a good sign. The pattern looked pretty simple early on and there was model agreement-- then it got complicated. It still is, hence why we haven't totally dismissed the possibility of a little snow

Posted by: Jason-CapitalWeatherGang | December 23, 2010 2:51 PM | Report abuse

If there were a way to pull a post I would. I'm sorry, that was yesterday. Emily litella - never mind! Sorry.

Posted by: jca-CrystalCity | December 23, 2010 2:52 PM | Report abuse

I think we have to be careful about making broad generalizations about what this system will bring to the area based on the latest model runs. Typically, these models trend west. I would be surprised to see coastal Carolina getting pounded with heavy, wind-driven snow with nothing here. The particulars of the latest Euro run simply do not make any sense given the history of such storms, but we'll see. We all remember that classic storm several years ago when the model predicted a storm heading out to sea and then six hours later we had a blizzard raging over central Maryland, so there is still hope for this to come together.

Posted by: brianmarkweber | December 23, 2010 2:52 PM | Report abuse

Wow @jca-crystalcity, that is definitely a much different forecast than CWG! It seems that meteorologists are not yet in agreement on this one by any means.

Posted by: SteveinAtown | December 23, 2010 2:53 PM | Report abuse

Question on forecasting snow amounts...

If I look at the 12z GFS run, I see the lightest color of green around DC for the 54 and 60 hr periods. The scale on the left appears to indicate the lightest green represents precip ammts between .01 and .1. Going with the middle, I could say .05 * 2 periods = .1" precip * 10 (snow/liquid) ratio and come up with 1" snow. Is that a reasonable interpretation for Saturday night?

Posted by: spgass1 | December 23, 2010 2:55 PM | Report abuse

JCA-

That's from yesterday, before the models shifted east.

Posted by: mason08 | December 23, 2010 2:57 PM | Report abuse

jca crystal city

that post is from 24 hours ago, a lot has changed since then for us

Posted by: cunninja4 | December 23, 2010 2:58 PM | Report abuse

SteveinAtown, the psoted accuwx statement was a day old. They may have changed their views

Posted by: wjunker | December 23, 2010 2:58 PM | Report abuse

Am I the only one that thinks the Euro has been pretty consistent througout, outperforming the other models? It isn't as though the low has fallen off the map. A difference of 50 miles in track always has huge implications for our area, but the guidance has been pretty good if you aren't asking for more than a model with limited resolution can deliver. While all the focus is on the track, intensity forecasts tend to be much less certain - and that may be the key to what we'll see.

Posted by: manatt | December 23, 2010 2:59 PM | Report abuse

Question on forecasting snow amounts...

If I look at the 12z GFS run, I see the lightest color of green around DC for the 54 and 60 hr periods. The scale on the left appears to indicate the lightest green represents precip ammts between .01 and .1. Going with the middle, I could say .05 * 2 periods = .1 inch precip * 10 (snow/liquid) ratio and come up with 1 inch snow. Is that a reasonable interpretation for Saturday night?

Posted by: spgass1 | December 23, 2010 3:00 PM | Report abuse

Ah, ok, didn't see that. My excitement overtook me. :) Thanks!

Posted by: SteveinAtown | December 23, 2010 3:02 PM | Report abuse

All I can say is this blows, warmer temps after this. Guess winter is over early in the D.C area. Was hoping for 2 good years in a row.

Posted by: dannythe357 | December 23, 2010 3:06 PM | Report abuse

dannythe357, where do you see temps warming? All I see are continued mid-30s, which is WELL BELOW NORMAL for this area (I have to use caps to remind people here of that).

Posted by: SouthsideFFX | December 23, 2010 3:17 PM | Report abuse

VTB's new snowcast
0-1" 60%
1-3" 30%
4"+ 10%
Things could change.
Based on most of the models trending 2 a miss or near miss, I never thought this had more than 30-35% chance of being a big snow.
2morrows model runs should give a clearer picture of what happens. Who knows, maybe they will shift the L 2 the W.

Posted by: VaTechBob | December 23, 2010 3:18 PM | Report abuse

Yes, but the big man will be coming and he has his terrorist list and he's going to hit and run dispensing instant justice to all the trembling kids around the world...

Posted by: Wildthing1 | December 23, 2010 3:22 PM | Report abuse

Yes, but the big man will be coming and he has his terrorist list and he's going to hit and run dispensing instant justice to all the trembling kids around the world... and the traumatized kids may never recover after waiting for the chimney intruder to stop by for cookies and vengeance...

Posted by: Wildthing1 | December 23, 2010 3:26 PM | Report abuse

spgass1, according to this site, dca gets around .048 from the 12Z gfs run which depending on the snow ratio could be 1/2 inch if it's 10 to 1 or 1 inch if it's 20. The ratios depend on the type and size of the flakes which is determined by by the thermal profiles in the clouds and where the snowflakes form and the amount of lifting. http://coolwx.com/cgi-bin/getbufr.cgi?region=VA&stn=KDCA&model=gfs&time=current&field=prec

Posted by: wjunker | December 23, 2010 3:37 PM | Report abuse

Nice knowing ya, Chersnowble. You had a good run and died too soon.

Posted by: JDK4 | December 23, 2010 3:40 PM | Report abuse

SouthsideFFX, I had heard that warmer temps are behind this storm. Just extremely upset about no snow. I have spent the last 3 days putting plows and spreaders on our trucks. Just goes to show with all the models nobody truely knows what is going to happen.

Posted by: dannythe357 | December 23, 2010 4:11 PM | Report abuse

I just experienced something that was yet another example of why I like CWG and I don't always like the local news.

Got through reading this piece and discussion, like all the snow lovers, the reality of just light precip setting in.

Then I went to News4 - The lead in music struck a big chord and Pat Lawson said - Brace yourself!

I was thinking, hey maybe Veronica had an update.

But it was not to be, she quickly was more somber and said just a light snow.

Thank you CWG for never going for those ridiculous methods the media uses.

Posted by: jaybird926 | December 23, 2010 4:21 PM | Report abuse

So are you guys discounting a major snowstorm this weekend? Do you think models are having trouble picking up on "time of phasing" in regards to the northern and southern energies. Wouldnt that change the stormtrack.

Posted by: StormChaserMan | December 23, 2010 4:41 PM | Report abuse

dannythe357 -
Its fun to look at weather models and make guesses. But weather is weather. If you're spending appreciable amounts of time setting up heavy equipment based on a storm predicted by one model (ECMWF) 5 (FIVE) days away....well that's your choice.

Snowstorms are kind of fun, but yesterday I remembered twice last year I had to dig out my heat pump ever 2-3 hours during both blizzards last year.

Posted by: AndrewRockville | December 23, 2010 4:42 PM | Report abuse

Hate the forecast, love your analysis...

Posted by: ennepe68 | December 23, 2010 4:48 PM | Report abuse

18Z GFS did move west slightly. However, not enough to make a difference in DC.

Posted by: bdeco | December 23, 2010 5:09 PM | Report abuse

the gfs did shift a little west by changing the phasing and now has a pretty significant storm for eastern MA northward to Maine. Cape cod would really get smacked so would eastern Maine. For us, we still get by passed though a dusting still seems possible as there is lots of RH.

Posted by: wjunker | December 23, 2010 5:16 PM | Report abuse

The odds probably don't favor a big snowstorm for DC, but it is still too close to call and too soon to rule it out.

At least the 18Z GFS does get the edge of the precip to DC. We are well within the circulation of the 850 mb upper low, which means that there is potential for bands to wrap back.

If the storm comes in 50-75 miles closer than being depicted, we could easily get a 6+ inch snow event. That is within the margin of error with the event still 72 hours away.

Posted by: frontieradjust | December 23, 2010 6:38 PM | Report abuse

Wes, thanks a lot for the info and site. Sorry for the double post earlier...

Posted by: spgass1 | December 23, 2010 7:26 PM | Report abuse

frontieradjust....

i SOOOOOOO needed to see that. thank you.

why didn't i get a reply from CWG when other people did? (just asking, not mad)

Posted by: SnowDreamer | December 23, 2010 8:36 PM | Report abuse

Our current "storm" is a good example of why you need to consider the overall long term weather pattern when forecasting a big snow in DC. Wes has found that DC has never gotten more than 17" snow in a moderate to strong La Nina (as we are currently experiencing) for the entire winter. Nearly all of our really big DC snows have been associated with a moderate El Nino (like we had last winter), usually in the favored Jan. 20 - Feb. 20 "window of opportunity". It seems that an energetic southern stream with a strong subtropical jet (a distinguishing feature of El Nino) is a necessary ingredient for a big DC snow. The weak, wimpy La Nina southern stream just doesn't do the job!

Posted by: buzzburek | December 23, 2010 10:03 PM | Report abuse

Our current "storm" is a good example of why you need to consider the overall long term weather pattern when forecasting a big snow in DC. Wes has found that DC has never gotten more than 17" snow in a moderate to strong La Nina (as we are currently experiencing) for the entire winter. Nearly all of our really big DC snows have been associated with a moderate El Nino (like we had last winter), usually in the favored Jan. 20 - Feb. 20 "window of opportunity". It seems that an energetic southern stream with a strong subtropical jet (a distinguishing feature of El Nino) is a necessary ingredient for a big DC snow. The weak, wimpy La Nina southern stream just doesn't do the job!

Posted by: buzzburek | December 23, 2010 10:03 PM | Report abuse

Snowdreamer, I doubt that the there will be much of a westward shift as the 18Z gfs is pretty much towards the western edge of the ensemble guidance but of course I could be wrong. The 00Z nam certainly didn't move in that direction. I guess it's possible since we still have a couple of days to go before verification. However, I like the probabilites that were posted in the blog. Sorry in the delay in answering.

Posted by: wjunker | December 23, 2010 10:27 PM | Report abuse

Buzz, my stats only go back to 1950 so there could have been some back in before we were born.

Posted by: wjunker | December 23, 2010 10:29 PM | Report abuse

Booooo. was so looking forward to some nice snow.

Posted by: amylorr1 | December 23, 2010 11:07 PM | Report abuse

OK I love snow...After I get home safely on Monday, it can snow til pigs fly! BTW..does anyone have a good resource for weather on 68 from Hancock to Morgantown?? Weather.com said flurries and well....they had to break out a few plows up around Deep Creak/Cheat Lake span. I just want to know what I am heading into!

Posted by: SPS1 | December 23, 2010 11:09 PM | Report abuse

Bummer!!! the Euro is supposed to be better due to a finer level of resolution.

Two things stand out however: First, this event won't be a huge snowstorm that far offshore! The Gulf Stream's out there, remember? Sea surface temps are probably in the high fifties and the air temps above the ocean are aoa 45F. Sure, there will probably be plenty of precipitation, but it's likely to be a rather cold wind-driven RAIN, not the "blizzard, we're gonna miss"! So much for a blown snowstorm.

In addition, as several folks have pointed out, there seems to be no vibrant Arctic push behind this yet-to-develop(!) storm. What does this mean??? Well the weekly outlook for CHICAGO has temperatures back up into the thirties there by New Years Eve. This ought to translate into forties or perhaps fifties out here. That's right...boring old forties, not a continuation of cold December to ring in the New Year. Any snow that falls here by Monday is likely to start melting rather than sticking.

Normally, the preponderance of high twenties to low thirties at daybreak translates here to a wintry mix-to-rain event here rather than the huge blizzard some model runs have projected. I bet we see highs of 45 to 50F by New Years Day--and any big snowstorm between Christmas Day and Monday becomes a yucky, slushy mess which continually refreezes at night and thaws after daybreak. Frankly, I'd rather be seeing a modest snow event follwed by a bitter Arctic outbreak this time of year.

One good sign...a mild New Year's eve bodes well for the big swing dance events at Glen Echo. The Spanish Ballroom is neither heated nor air-conditioned, and could be rather uncomfortable in a subfeezing Arctic outbreak with the high winds we have been experiencing of late.

Posted by: Bombo47jea | December 24, 2010 12:05 AM | Report abuse

Can you people do something about the cold wind we've been stuck with this month? ;) - LOL

Posted by: DontGetIt | December 24, 2010 7:40 AM | Report abuse

The 12Z gfs now gives dc and east around .25 inches of liquid with more that 0.1 in the western suburbs addint interest to the sunday forecast. Right now I'm not sure what to make of it.

Posted by: wjunker | December 24, 2010 11:09 AM | Report abuse

Wes
neither do I. Ordinarily, I'd say lets wait for the ECMWF, but... ?

Posted by: ronbcust | December 24, 2010 11:23 AM | Report abuse

ronbcust, messages from HPC indicate the gfs may have had initialization problems so they are inclined not to believe it. Its esnemble mean strongly supports it as does the japanese model forecast so the GFS is not totally alone. I think wait for the euro and the 15Z sref ensemble mean. I'll try to post something here when I see them. I won't be doing an official blog today.

Posted by: wjunker | December 24, 2010 12:57 PM | Report abuse

the 12Z euro is way east of the gfs and is in the same camp as the ggem, nam, ukmet models and bulk of the 09Z sref ensembles. The on model that agrees with the GSF is the japanese model. Right now the consensus supports our earlier forecast and probabilities.

Posted by: wjunker | December 24, 2010 1:46 PM | Report abuse

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