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

[Sydney Claridge]

5 minutes ago, aggiegeog said:

Models are doing terrible on surface temps today. They are running way too warm. Which in turn leads to forecasts including the NWS being way warm.

Agreed.  Even just looking at the RAP used on the SPC Mesoanalysis site, that model placed the freezing line about three counties too far west.  At least most of DFW seems to be above freezing (though just barely) now, though some places in Tarrant and Denton counties still seem to be at or just below the freezing mark.

[aggiegeog]

17 minutes ago, BrandonC_TX said:

Agreed.  Even just looking at the RAP used on the SPC Mesoanalysis site, that model placed the freezing line about three counties too far west.  At least most of DFW seems to be above freezing (though just barely) now, though some places in Tarrant and Denton counties still seem to be at or just below the freezing mark.

NW Tarrant county is experiencing much worse icing on the roads than they expected. Surface roads should be ok but anything elevated is a nightmare.

[raindancewx]

The past eight days (12/26-1/2), once 1/2 is included have had the second coldest mean high in Albuquerque since the 1931-32 winter - 34.0F (11F below 1932-2018 average)

[aggiegeog]

As expected along the I-20 corridor I do not think we will see any snow accumulations late today into tomorrow morning but I do expect some snow flakes in the air. If we get any heavy showers then some spots could see a coating as that would drop temps from near 40 to the mid 30s.

[aggiegeog]

The GEFS is beginning to pick up on a potentially great mid month pattern with a -EPO, -AO and -PNA.

[aggiegeog]

GEFS still showing a good late month pattern. For mid month the pattern is still loading up so nothing impressive down here yet.

[aggiegeog]

Potential growing for a Southern Plains winter storm next weekend. Many more chances beyond that.

[raindancewx]

I'm expecting a fairly big system to come through the West sometime around 1/23. The big SOI drops have all showed up as storms at a lead of 10 days. The problem is they are all weak and/or moisture starved so far. This is the "SOI calendar".

Date	Tahiti (hPa)	Darwin (hPa)	Daily Contribution	30 day Av. SOI	90 day Av. SOI
13 Jan 2019	1009.64	1006.95	-9.04	2.30	2.80
12 Jan 2019	1011.02	1007.65	-5.84	3.32	3.14
11 Jan 2019	1012.30	1007.20	2.31	4.19	3.51
10 Jan 2019	1011.56	1008.50	-7.30	4.56	3.75
9 Jan 2019	1011.75	1007.65	-2.40	4.94	3.94
8 Jan 2019	1012.44	1007.80	0.15	5.05	3.98
7 Jan 2019	1012.09	1008.40	-4.33	4.93	3.97
6 Jan 2019	1010.17	1007.40	-8.66	5.15	3.97
5 Jan 2019	1008.86	1008.20	-18.60	5.64	3.97
4 Jan 2019	1009.55	1009.25	-20.30	6.46	4.11
3 Jan 2019	1009.90	1008.05	-13.00	7.42	4.31
2 Jan 2019	1009.71	1007.10	-9.42	7.94	4.48
1 Jan 2019	1009.66	1006.60	-7.30	8.53	4.66
31 Dec 2018	1010.49	1006.85	-0.42	9.23	4.67
30 Dec 2018	1010.45	1005.45	6.64	9.46	4.50
29 Dec 2018	1011.15	1004.35	15.98	9.44	4.16
28 Dec 2018	1010.84	1003.60	18.27	9.33	3.79
27 Dec 2018	1008.54	1004.50	1.66	9.23	3.48
26 Dec 2018	1008.83	1005.75	-3.32	9.37	3.39
25 Dec 2018	1009.69	1005.60	1.92	9.48	3.37
24 Dec 2018	1010.56	1005.75	5.66	9.41	3.34
23 Dec 2018	1011.65	1005.45	12.87	9.35	3.16
22 Dec 2018	1011.39	1005.10	13.34	9.15	2.81
21 Dec 2018	1011.94	1005.35	14.89	8.83	2.36
20 Dec 2018	1012.71	1007.00	10.33	8.53	1.91
19 Dec 2018	1013.25	1008.05	7.68	8.40	1.63
18 Dec 2018	1014.64	1006.70	21.90	7.89	1.49

[aggiegeog]

We are finally within a week of the much anticipated flip to the cold and snowy pattern. The first chance for wintery weather comes behind the front this Fri into Sat (thunderstorms to sleet to snow type set up) then another chance for around next Tue. Beyond that look for storms to bring chances for wintery precip every 4 or so days. Not all will be hits, but there is a high likelihood that at least a few will be.

[aggiegeog]

Man the next 6 weeks look incredible. Cold and storms so snow is very likely. This will be among the coldest Februarys we have ever seen across NAM. -EPO, -AO, -NAO and -PNA along with a weak El Nino. Could not write up a better atmospheric set up for the eastern 2/3s of the US.

[raindancewx]

2 minutes ago, aggiegeog said:

Man the next 6 weeks look incredible. Cold and storms so snow is very likely. This will be among the coldest Februarys we have ever seen across NAM. -EPO, -AO, -NAO and -PNA along with a weak El Nino. Could not write up a better atmospheric set up for the eastern 2/3s of the US.

My concern initially, for say, five days, is the MJO will move through phases 4-5-6, which are warm this time of the year for the East, sometime between 1/20 and 1/25 if the European depiction is right at fairly high magnitude.

I do think the real transition is starting now, my analogs had 5" in Boston through mid-January and then 30" after, so its kind of right on time, but the transition is late enough that I think most places in the East finish slightly warmer than normal for DJF overall. Also, I don't think it will last six weeks for the whole country, I think the core of it is between the Rockies and Mississippi by mid-February, but I agree with your assessment generally.

[aggiegeog]

32 minutes ago, raindancewx said:

My concern initially, for say, five days, is the MJO will move through phases 4-5-6, which are warm this time of the year for the East, sometime between 1/20 and 1/25 if the European depiction is right at fairly high magnitude.

I do think the real transition is starting now, my analogs had 5" in Boston through mid-January and then 30" after, so its kind of right on time, but the transition is late enough that I think most places in the East finish slightly warmer than normal for DJF overall. Also, I don't think it will last six weeks for the whole country, I think the core of it is between the Rockies and Mississippi by mid-February, but I agree with your assessment generally.

The most severe cold looks to be this weekend through mid Feb, but high end snowfall is likely beyond that. Could see a longer version of what we saw last year at this time with high ratio snow and very cold temps. I think the coldest for Texas will be early Feb though teens are possible Sun and Mon along and north of I20 and again later next week.

[aggiegeog]

Man I cannot get over how awesome this pattern looks to be for late this month into Feb. Everyone east of the Rockies will be in the deep freeze for a few weeks with minor systems bringing light precip. By mid month I could see a big storm develop if we can get a lobe of the Aleutian low to undercut the -EPO ridge and dive into So Cal. If that happens that could be the big winter storm for the South and it may be enough to disrupt to overall deep freeze pattern by breaking down the NW Atlantic high. For Late Feb into Early March it will be interesting to see if the cold relocates or re establishes itself over NAM in time for a last winter storm before spring. Interspersed in the deep freeze could be weak to moderate systems in the cold flow to bring some nice snow by Texas standards.

[cheese007]

Outside chances of both severe weather and winter weather within a 24 hour period is peak north Texas

[raindancewx]

Blue Norther level cold front in the coming days. CPC is impressively confident in the cold, they rate this as a 4/5 confidence in the discussion.

We hit 50F here today, first time since Christmas, three weeks ago. Latest in January we've had our first 50F reading since Jan 1977.

[aggiegeog]

Looking like we may be dealing with +PNA mess through the end of the month shunting a good bit of the cold to out east ala Jan 2014. Thankfully being late Jan it still will be chilly, but more concerning is that may cut off some of the STJ we have enjoyed this season. Hopefully the pattern can retrograde back west before too long. 2014 still managed an epic March storm so things are not over by a long shot.

[aggiegeog]

Looks like the PV lobes have potential to dig under the +PNA ridge far enough to tap into the STJ per the op and ens model runs lately so our snow outlook for the next few weeks is still high. Today's supposed warm day is a cloudy 60 degrees and we have not had a torch all winter. It has been wet and mild all winter, very El Nino like, thankfully the SSW event is going to supply the cold though not centered over us.

[cheese007]

Big, wet snowflakes falling just south of Prosper in McKinney

[aggiegeog]

28 minutes ago, cheese007 said:

Big, wet snowflakes falling just south of Prosper in McKinney

HRRR has been spot on with this system. Another light band to follow later this morning. Both bands should stay north of I-20/30. Y'all enjoy.

[cheese007]

25 minutes ago, aggiegeog said:

HRRR has been spot on with this system. Another light band to follow later this morning. Both bands should stay north of I-20/30. Y'all enjoy.

Around what time can that be expected?

[aggiegeog]

25 minutes ago, cheese007 said:

Around what time can that be expected?

Couple hours if it gets its act together. At best it looks like light snow for northern DFW.

[cheese007]

Meanwhile a tornado watch has been issued until 1 PM for parts of Louisiana and Mississippi

[aggiegeog]

Looks like backend post frontal snow is possible Wed morning from Austin to Texarkana, amounts would be light maybe up to a couple inches. Bust potential is high as precip will be on its way out as the cold rushes in, some chance for high bust if cold is faster. Another chance on Friday bit details are slim on that.

[raindancewx]

Low Solar + El Nino in March is an interesting combo historically. 

[aggiegeog]

GFS and Euro still show up to a couple inches of backside snow Wed from the Hill Country up through NE TX. Maybe a bit for the SE side of DFW per the Euro. GFS would offer a bit in N Houston metro. Where I am at, NW of Tyler, looks to be as good of a spot as any.

[raindancewx]

I was looking at annualized sunspot activity in various US locations v. March high temperatures. 

Looked at Boston, Philadelphia, Jacksonville, Detroit, St. Louis, Memphis, Bismarck, Amarillo, El Paso, Albuquerque, Flagstaff, Phoenix, Cheyenne. Just about every site has weak correlations between solar activity and March highs, but the zone around Amarillo is definitely strongest. R squared for Amarillo for 1932-2018 is 0.10 - that's pretty damn strong. Every 100 sunspots lost is like 2F added to the high. The weakest correlations are in areas right on the coast, especially away from the equator. A lot of places seem to have a weak correlation just because 1958 was cold and had near record solar activity, but in Texas and the Southern Plains it works in the other high solar years too.

[aggiegeog]

The E TX snow potential still looks at least possible tonight. Some good moisture streaming out of C TX right now. Some flakes already reported in DFW area.

[cheese007]

Some brief sleet showers over in Carrolton per Twitter

[aggiegeog]

2 minutes ago, cheese007 said:

Some brief sleet showers over in Carrolton per Twitter

mPing and posts on other forums confirm snow and sleet in northern DFW. The back edge of the precip is not progressing much at all so chances increasing for those E I35 to see something though I still think you have to be east of DFW for accumulations. I think SHV is crazy for not even inserting mix into tonight's forecast.

[cstrunk]

No wintery wx thus far in Longview, TX. Unless you count frost, we've had that.

Shreveport has added a 20% chance of snow late Monday night, so we have something to keep an eye on. The neighbors to the north don't seem very optimistic about the rest of winter, from what I gather in the other winter wx thread.