aggiegeog

8 minutes ago, bubba hotep said:

I just glanced at things earlier but it looks like a trade off between solutions with warmer coming with a better chance of winter precipitation vs. a colder solution FWD. 

Things seem to be coming in line with my original thinking of a system sneaking in behind the front. We will have to see if the mid level moisture can fill in as that is what was lacking when I looked at the models this morning. If we do get some frozen precip then Thursday afternoon and Friday morning would likely be colder than forecasted.

Man this month is setting up to be brutally cold. I would not be surprised to see us reach the single digits for the first time in 20 years and maybe challenge 83 and 89 if a good -EPO sets up. 

Rain has been good here so far. It's been a couple hours since I last checked, but we were messing 1.5" then.

50 minutes ago, bubba hotep said:

The 00z Euro looks to be trending to a "warmer" solution for next week with this outbreak looking a lot like some of the others from the past couple of seasons. The heart of the cold stays off to the NE vs diving straight down the spine of the Rockies. I guess on the bright side, the GFS has backed off the mid-month 70s? 

As long as we have -PNA I am hopeful that the cold will come straight south though the -NAO is a bit too negative for my liking. It may turn out that the front early next week will be even stronger down here with cold air in place already and more snow to work with down the Plains plus a more +NAO.

It sure is going to be a wet and chilly weekend, already up around 0.5" here and 47 degrees. That map is looks reasonable though there is some chance of more. We only look to get a one day break on Tuesday before more rain and much colder weather crashes through on Wed. Temps likely won't reach 45 for days afterwards with some days struggling to reach freezing. Moisture behind the front looks meager but models always struggle to see the little systems that can bring us snow behind these.

4 minutes ago, DFWWeather said:

The 12z GFS vs 0z ECMWF are very different on next week. GFS is warmer than ECMWF and has been the whole time. Shouldn't this be the other way around? GFS has a more NW SE trajectory sending the coldest air off to our north and east giving just kinda a glancing blow.

The GFS is worthless right now as far as the midweek storm is concerned. With a -PNA and +NAO there is no reason for the storm to take the track it shows.

7 minutes ago, DFWWeather said:

This Arctic front looks as though it will penetrate all the way to Central America!

Yep, this kind of cold is very dense and it just flows south even with minimal upper air support.

This system will also extend the snow pack into the Central and maybe Southern Plains. Also, plenty of cold air will remain in western Canada for subsequent fronts to tap into. There appears to be a chain of fronts through at least mid month and likely into January.

27 minutes ago, bubba hotep said:

The 00z Euro EPS backed way off on the snow chances vs. 12z. Only one member shows anything for DFW next week. 

Many model runs to go so we will see, but it looks like a pretty dry system. Maybe we can get us a little NW flow kink to bring some snow showers within the Arctic air mass.

It sounds like some of the Euro ensembles have a winter storm with the front. If we get snow or ice then the first single digit code in a very long time is possible. Red River counties could flirt with 0. Man I am getting excited.

Next week looks like it will be a McFarland event with a Rio Grande Valley freeze. Interestingly it will be -WPO (Bering Sea ridge)driven unlike most others which are -EPO driven (ridge over GoA and into AK). North of I-20 highs could be sub freezing with lows in the teens for a day for a day or two.

18Z GFS continues idea of light snow at least along the Red River Wednesday morning right behind the front. By Thursday it has a 1041mb high over N TX. With these two things I think it is underdoing the lows Thu and Fri as it shows mid to upper 20s with DPs in the teens with a very light wind going calm.

2 minutes ago, bubba hotep said:

12z Euro looks chilly, has the northern burbs of DFW with sub freezing highs next Thursday. 

That would not be surprising. The GFS is way too progressive with this system while the Euro is slower but colder. It is very cold in Canada so the GFS idea of only getting as cold as we were this morning without the support of a very cold Arctic seems unreasonable. Thursday morning looks to be very cold (single digit and teens windchills) as there will likely still be some wind, Friday morning will likely see the coldest air temperatures (I expect rural areas to make a run at the teens). These temperatures could be moderated if we end up with any shortwaves in the cold air, but we will happily trade a hard freeze for snow.

It looks to me like the 12Z GFS shows flurries behind the front Wed morning. Even if this is not exactly the solution still being almost a week out the idea is on the table for at least some kind of pulse or maybe multiple NW flow pulses within the Arctic air mass. These are almost impossible to nail down until right before they come through though in the past we have had some good snow out of these with little warning.

Another freeze here with 30 at my house and 28-32 in surrounding areas. Looks like E TX is in for a 2-6" rain event this weekend. Next week's front looks to come in sometime between Wed morning and Thu morning with storms out ahead of it. Temps will fall from the 60s ahead of the front into the 30s and 40s for daytime highs late next week with lows in the 20s. We will watch to see if there are any small systems behind the front that could squeeze out some precip in the cold air. This looks to be the first in a series of Arctic fronts as Western Canada stays much below average temperature wise and this will be released anytime the NE Pacific ridge noses up towards AK.

Also this weekend's storm looks to bring heavy snow to the mountains of southern NM and some snow to most of NM and the panhandles of TX/OK.

8 minutes ago, DFWWeather said:

12z ECMWF now down to -9.3°C at H85 for DFW next week's Arctic blast Dec 8-10th with 526 partial thickness. Brrrr!

All major models show similar. With a solid snow pack up north from Mongolia to I-40 and that kind of air above us we should be looking at the coldest air since 2014. GFS has near 0 dew points on the 9th.

Looks like the Panhandle has a shot at heavy snow on Saturday depending slight shifts. Canadian is heaviest with near a foot while GFS is slightly warmer and south so just a few inches on it. The NAM and other shorter range models will begin coming into play over the next few days to nail it down better.

8 minutes ago, Quixotic1 said:

Thanks.  I'd take 45 after last year.  I'd like to see a bit colder.  42 would be nice and not too unreasonable.  2009 had some cold and snow. Will have to go and check just how cold.  

42 would be awesome, hopefully we can get a streak of 2 or 3 days below freezing which likely would be the result of snow on the ground. This is possible for the initial cold blast but more likely somewhere around 12/18ish.

10 minutes ago, Quixotic1 said:

So, talking about cold Decembers, we got four that stand out during the time period of 1900 to 2008:  1908, 1913 and 1989 (2.35, 2.26 and 2.47 Standard Deviations respectively) and the grand daddy of them all:  1983 which is a whopping 3.77 Standard Deviations below normal.

Great analysis, for this year my bet would be on a mean around 45 as we have a warm background state with lots of polar blocking and a very cold source region.

1 hour ago, DFWWeather said:

Don't forget January 8, 2015 the temps were 16°F to 38°F that day at DFW. Based on current model data, next week would be a little warmer on the low and maybe a tad colder on the high. So it would be at least as cold as that. Unfortunately, this also looks like a real quick shot much like January 2015 with no snow or ice. The -EPO and -NAO may trend positive again before the month is out which would negate any 1983 reprises.

The key to any lasting cold is the pesky GoA low. If we can get rid of that everything else is in place for cold. Until then we look to have roller coaster temps of highs around 70 for a few days then highs around 40 for a few days and back. Thankfully it looks like we will have consistent precip events and one is bound to time out right for winter weather.

39 minutes ago, bubba hotep said:

12z GFS looks like it keeps DFW below 40 for the high next Thursday. It is a ways off but there is growing agreement across operational and ensemble models that DFW could see the coldest air in years with this shot.

That seems almost certain at lease since March '14. A ~1050mb high over the Plains will be very nice with a cold W Canada. NW of where the surface low tracks will see some heavy wintery precip it looks. Hopefully the low trends south as is typical at this range.

24 minutes ago, DFWWeather said:

Today's 0z ECMWF is down to -8.5°C at H85 for the potential Arctic blast December 8th through 10th. If that were to verify, that would mean the coldest air at DFW in nearly 2 years. Which, of course, isn't saying much as the lowest temp all last winter was an unprecedented 27°F and we had no days below 40°F for highs. Who knows what is going on with today's 0z and 6z operational GFS. It seems to be odd with no Arctic air as the last several runs have had it.

Yea, for now I am tossing the recent GFS runs out. -40F air over NW Canada doesn't just fade away especially not with a -EPO look.

10 hours ago, Quixotic1 said:

I've been thinking about 83.  I'd be genuinely interested to see how extreme it was in terms of averages.  I've got all that data on a csv file so I can probably put it on a distribution easy enough.

December is sure looking like 83 in general. The extremes of the heart of that outbreak will be hard to ever replicate though. A 580+ dm 500mb ridge will into Alaska is something we will be lucky to ever see especially coupled with a cold background state.

I have been telling people to not sleep on the potential for snow this weekend. It is not likely, but these type systems that dive into Mexico this time of year tend to surprise. And if it does come through at night then our chances are even better. I will continue to watch it. 

This will be followed by true Arctic air a few days later and we will watch to see if we can get a shortwave in the cold air.

I got about 2" of rain from this system and the NM mountains got 3-6" of snow out of it. 

The pattern the models are showing with blocking over the top and low heights over the SW should result in a snowy December for the SW and frequent precip in the Southern Plains with cold coming later in the month for the S Plains as a -EPO develops.

27 minutes ago, bubba hotep said:

First fantasy snow storm for N. Texas on the 06 GFS!  

Saw that. If the surface high can strengthen a bit more than shown on this run I will have more faith in it, but awesome to look at modeled snow.