Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 8

[DFWWeather]

9 minutes ago, aggiegeog said:

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.

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.

[Quixotic1]

So, talking about cold Decembers, we got four that stand out during the time period of 1900 to 2008:  1909, 1914 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.  

 

 

[aggiegeog]

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.

[aggiegeog]

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.

[DFWWeather]

17 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.  

 

 

December 1908 was warm at DFW (+3.8 to be exact) with coldest temp of the month 25°F. December 1913 was also just -1.4 for the month with coldest temp of 26°F at DFW. Those years don't stand out. Did you mean 1914 and 1909? Those were -7.4 and -8.0 respectively.

[Quixotic1]

1 minute ago, DFWWeather said:

December 1908 was warm at DFW +3.8 to be exact with coldest temp of the month 25°F. December 1913 was also just -1.4 for the month with coldest temp of 26°F at DFW. Those years don't stand out. Did you mean 1914 and 1909? Those were -7.4 and -8.0 respectively.

Yes.  You're right.  I pulled the data for another reason mostly to do with the winter overall and we end up with the old "do we use 83 or 84 to describe the winter" bugaboo.  It's easier to write one year than two and 108 years is a lot.  Thanks for the catch.  

[DFWWeather]

1 minute ago, Quixotic1 said:

Yes.  You're right.  I pulled the data for another reason mostly to do with the winter overall and we end up with the old "do we use 83 or 84 to describe the winter" bugaboo.  It's easier to write one year than two and 108 years is a lot.  Thanks for the catch.  

I got you, I figured it was something like that. When I saw your post, I wanted to look into more of details on the early 1900 Decembers to see what actually happened in those months in terms of length of cold and snow/ice. Thanks for the great analysis.

[Quixotic1]

10 minutes ago, aggiegeog said:

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.

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.  

[aggiegeog]

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.

[aggiegeog]

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.

[DFWWeather]

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!

[aggiegeog]

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.

[raindancewx]

Do any of you like 1978-79 as an analog? It was a borderline La Nina (-0.4C) in Fall of 1978, but it weakened to Neutral in winter. It followed two El Nino winters (76-77, 77-78), and occurred after a reversal in the long standing sign of the PDO (1976/2013 - although the more recent flip seems to be a spike more than a 30-year flip). I ask because the La Nina seems to be weakening, we're following two El Ninos...and the cold experienced in the US in January 1979 (-8F to -20F over most of the US) has been occurring over Asia for the past two months.

January 1979 was stupid cold in the middle of the country - including TX, OK, etc.

[Quixotic1]

59 minutes ago, raindancewx said:

Do any of you like 1978-79 as an analog? It was a borderline La Nina (-0.4C) in Fall of 1978, but it weakened to Neutral in winter. It followed two El Nino winters (76-77, 77-78), and occurred after a reversal in the long standing sign of the PDO (1976/2013 - although the more recent flip seems to be a spike more than a 30-year flip). I ask because the La Nina seems to be weakening, we're following two El Ninos...and the cold experienced in the US in January 1979 (-8F to -20F over most of the US) has been occurring over Asia for the past two months.

January 1979 was stupid cold in the middle of the country - including TX, OK, etc.

Worst ice storm I ever saw was the 1978 New Year's Eve storm.  DFW didn't get much but where I lived we lost half our trees, had icicles hanging from the second story all the way to the ground and were without power for 6 days.  Couldn't even go outside because of all the downed power lines.

I can see 78-79 as well as 83-84.  The extremity of the cold makes me hesitate.  But as analogs, I think both are serviceable.  AMO had a tendency to be negative back then if I remember correctly.

[DFWWeather]

Today's 0z models, especially ECMWF, have come in quite a bit warmer for potential Arctic air next week. The H85 temps have warmed to -4°C for DFW with the brunt of the arctic air shunted east across the north. The 12z GFS even warmer.

Shockingly the yo-yo ride continues with the 12z ECMWF back on board to significant Arctic air with H85 temps back down to -8.3°C for DFW.

[bubba hotep]

[bubba hotep]

On 11/29/2016 at 7:32 PM, raindancewx said:

Do any of you like 1978-79 as an analog? It was a borderline La Nina (-0.4C) in Fall of 1978, but it weakened to Neutral in winter. It followed two El Nino winters (76-77, 77-78), and occurred after a reversal in the long standing sign of the PDO (1976/2013 - although the more recent flip seems to be a spike more than a 30-year flip). I ask because the La Nina seems to be weakening, we're following two El Ninos...and the cold experienced in the US in January 1979 (-8F to -20F over most of the US) has been occurring over Asia for the past two months.

January 1979 was stupid cold in the middle of the country - including TX, OK, etc.

What does the Pacific as a whole like for that year? The MEI is a decent match but the PDO doesn't look like a very good match. 

[bubba hotep]

18z GFS has temps in the 70's by mid-Dec... not a chance of snow to track on the models...

 

[raindancewx]

The oceans aren't a great match to 1978, but the Atlantic was closer than I expected it to be. 1983 is fairly close, but off in certain spots.

I like a blend of 1937, 1943, 1959, and 1983 for the oceans as an ~80% match. It's a bit off in the Western Atlantic/Western Pacific.

I formalized my "June to November" observed highs v. forecast thing - for the last 30 years, it shows a small amount of skill for forecasting seasonal temps here. It's something like 80% confidence at +/-3F for it's DJF estimate (range is 12F historically, 44F-56F, so it cuts out maybe half the uncertainty?), and it's still ~67% at 2.3F. It's about 15% better than guessing the average (49.5-49.6F) each year. Anyway, it says ABQ has a mean high of 48.6F - and thus an 80% chance we are within 3F of that. Against the 1931-32 to 2015-16 winter time frame, that's -4F to +2F - a full 2.3F colder than last year, when the hindcast came up with 50.9F +/-3F. The Spring has either less variability or this is a better tool for Spring, as it's +/-2.25F for MAM 80% of the time, and +/-1.8F 67% of the time. Warm Spring is slightly favored in my area, but likely near average.

I keep harping on 1978 because it is a very strong match for my last six months of temperatures here - but in my area it wasn't a particularly cold winter. I'm somewhat partial to lumping winters after two El Ninos in a row together - it takes longer to cool the oceans down than in a normal El Nino to Neutral/La Nina transition. So I look pretty hard at the winters starting 1941, 1942, 1959, 1970, 1978, 1988. Just from that list, 1942, 1959, 1978, and 1988 are all somewhat similar to now, at least for my observable weather. 

[aggiegeog]

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.

[bubba hotep]

Nice to see some over performing cold. Last time I looked at my NWS point forecast yesterday it had a low of 37. Right now - 31! 

[bubba hotep]

Pretty strong signal that a good portion of our subforum will see soaking rains:

[aggiegeog]

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.

[Quixotic1]

Looks like a bomb might go off in the upper midwest next week.  978?  

[Casualbrain]

I'm going to be in the Canyon Lake area over Christmas - hoping it's not too cold so I can go water skiing

[DFWWeather]

1 hour ago, aggiegeog said:

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.

The 12z GFS is significantly warmer then ECMWF,  both at the surface and at H85,  with this cold blast due to the weaker upper low. The ECMWF and CMC are colder. Will this be colder than anything we saw last year at DFW? Coldest low was 27°F last year. I'm thinking right now we could be 23°F to 25°F at the coldest at DFW Airport. What maybe even more interesting is the intense cold coming after this where the ECMWF has nearly -40°C air entering the CONUS. Where that goes will be interesting?

[bubba hotep]

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

[aggiegeog]

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.

[DFWWeather]

8 minutes ago, aggiegeog said:

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.

12z ECMWF came in colder back to the -9°C. If that holds, I wouldn't be surprised (presuming excellent radiational cooling setup) if DFW Airport doesn't make a run for the upper teens. The ECMWF is bone dry.

[bubba hotep]

Just now, DFWWeather said:

12z ECMWF came in colder back to the -9°C. If that holds, I wouldn't be surprised (presuming excellent radiational cooling setup) if DFW Airport doesn't make a run for the upper teens. The ECMWF is bone dry.

It look like teens would be a lock for the northern burbs with that setup.