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

[raindancewx]

Looks like a nice storm for New Mexico.

[It's Always Sunny]

Absolutely torching in Texas today. 81F at my house which is nearly 25F above normal.  DFW may tie or break its daily record of 80F.  It's at 79F now with skies clearing.

[aggiegeog]

36 minutes ago, It's Always Sunny said:

Absolutely torching in Texas today. 81F at my house which is nearly 25F above normal.  DFW may tie or break its daily record of 80F.  It's at 79F now with skies clearing.

Cloudy and showery around Tyler but still in the low to mid 70s. Glad we will be done with warmth for a while after this.

[cheese007]

3 hours ago, It's Always Sunny said:

Absolutely torching in Texas today. 81F at my house which is nearly 25F above normal.  DFW may tie or break its daily record of 80F.  It's at 79F now with skies clearing.

Ended up breaking that recore with an official high of 81. Last 80 or above day was November 19th so we didn't even go two months before we ended up back in what's normally May/June weather. Hopefully not a preview of things to come for summer

[raindancewx]

I'm a big fan of the 3-km NAM at this range. Let's hope it verifies. Main issue for me will be if it gets cold enough. Dew points are low teens. But still in the upper 40s at almost 10 pm which is not ideal. I think we'd wet bulb to 36F or so at the moment, not quite cold enough/dry enough for snow. But the cold does seem to making the climb over the 7,000 pass into the Rio Grande Valley.

[It's Always Sunny]

13 hours ago, raindancewx said:

I'm a big fan of the 3-km NAM at this range. Let's hope it verifies. Main issue for me will be if it gets cold enough. Dew points are low teens. But still in the upper 40s at almost 10 pm which is not ideal. I think we'd wet bulb to 36F or so at the moment, not quite cold enough/dry enough for snow. But the cold does seem to making the climb over the 7,000 pass into the Rio Grande Valley.

-SN in ABQ. Our official forecast is up to 1" but if it stays just cold enough I think 1-3" is certainly possible.Those temperatures around 750mb are going to be the determining factor.

[raindancewx]

The thing that drives me nuts about Albuquerque is the airport does BS-y things with snow numbers, and precip in general. So they reported 0.09" of liquid equivalent as snow through about 5 pm. That number somehow is only 0.2 inches of snow. Despite temperatures 30-32F the entire period of accumulating snow. It was almost 60 yesterday, but it seems like it should be at least 0.5 inches. Visibility was under 2 miles for much of the snow Most of the city likely got far more precipitation too, although that's partly a snow shadowing issue. They'll probably update the snow total to something more reasonable later. The model precip was way overdone for sure, some of the models had 0.3-0.7" in the city, with half as snow. It's more like a 0.1-0.3" storm I'd say. 

The band in Arizona is likely to bring some additional precipitation, probably as snow. I've got one inch at my house a 6 pm, which is consistent with about 0.10" liquid so far.

[It's Always Sunny]

ABQ ended up reporting 0.7" snow (midnight to midnight) so it matches your expectations. I don't know what the liquid equivalent was with that final total but as you know ABQ gets crap ratios frequently due to their climate/geographic location (snow shadowing).

[raindancewx]

The official site had 0.15" as snow, all freezing or below, and reported 0.7". I had 1.5", and my co-workers on the west-side of town had around 3 inches.

The airport has had 5.3" to date, which is above the average through 1/16.

I've had 7.5" in November, 0.3" in December, and 2.0" total in January, about 10 inches total - same elevation as the airport, due north, with some snow shadowing here too. We do get more snow up here, but I still find their totals to be kind of funky most of the time. 

For the airport totals I try to use this formula:

Snow = (40-Temp)x(Precip as Snow*(1-EW/50), where East Wind is air pressure in MB in Amarillo + air pressure in Colorado Springs - ABQ air pressure x2

In this case...

Snow = (40 - 31) x (0.15)*(1-(9/50) =  

Snow = (9) x (0.15)*(0.82)

Snow = 1.1 inches

The East wind score went from roughly 14 to 5 over the duration of the event where at least parts of the city were getting snow. 

My assumptions had been more like this for the airport going in -

Snow = (40 - 34) x (0.25) x (1-(5/50) =

              6 x 0.25 x 0.9 = 1.4

I don't doubt they got around an inch, just seems a touch low for 0.15" liquid equivalent, with temperatures below freezing when all of it accumulated.

[It's Always Sunny]

Ratios were crap though doesn't matter if it's freezing at the surface. 5:1 ratio amounts will give you that.

[raindancewx]

My formula attempts to account for the ratio using the (40-Temp) portion. The colder it is, if you look historically, the less impact the East wind thing has. I've done a lot of testing on that formula - it tends to be within an inch of what it reported at the airport. This is one the better write ups about it.

http://www.theweatherprediction.com/weatherpapers/011/index.html

For the November storm, the numbers were like this -  should say the 'precip' value is a double weighted 3-km NAM, double weighted Euro, and single weighted GFS value for snow divided by five, i.e. 'modeled precip'. I know you have to look at soundings to make sure there is nothing weird going on, but assuming there isn't, you can use it pretty cleanly.

Snow = (40-Temp)x(Precip as Snow*(1-EW/50)

Snow = (40-30)x(0.6*(1-((1020+1024)-(1017x2))/((50)

Snow = (10 x 0.6) x (1-(44-34)/(50)

Snow = (10 x 0.6) x (1-(10/50)

Snow = (10 x 0.6) x (1-0.2)

Snow = (0.6) x (0.8)

Snow = 4.8". The airport got 4 inches.

[raindancewx]

 

[raindancewx]

I actually got that wrong - we topped 29.2% briefly in 2010. Anyway, it looks like it might snow a bit tomorrow, although I think with the much higher dew points it is unlikely to be as cold or as much snow as in the last system. Expecting 0.25" precipitation for Albuquerque, and maybe 0.5" or less as snow. Dew point is 22 though, at this time before the last system it was more like 5. With the higher dew point, I'd like to see the air temperature / dew point blend below 38/22 by Midnight for snow on Tuesday.  The last system was 44/10 at Midnight I think, and eventually got down to 30F.

[cheese007]

Well at least it has been cold here! Was worried that we'd be hot all through next October for a brief moment 

[aggiegeog]

Looks like some snow could mix in for northern E TX tomorrow morning. Up along I-30 there could be a dusting with flakes down to I-20 or a bit south. It'll  be a cold rain into Thursday here snow or not.

[aggiegeog]

35 with rain here. Some sleet earlier. The I-30 corridor is getting snow though.

[cheese007]

39 degrees and raining is so on brand for DFW the last 5 years. Quickly running out of time for a more meaningful snow event

[aggiegeog]

43 minutes ago, cheese007 said:

39 degrees and raining is so on brand for DFW the last 5 years. Quickly running out of time for a more meaningful snow event

Eh, our snow season is really mid February through early March.

[raindancewx]

By the end of the month, my outlook for January, warmed up 2F may end up being fairly close to what actually happens. This was my blend from October, but with +2 added on.

[aggiegeog]

GFS ensembles getting somewhat interesting for next week with a ridge off of the West Coast and an upper low moving into TX from the SW. We are in a very El Nino like pattern so nothing super cold but we just need temps in the mid 30s for snow with an upper low doing the rest.

[cheese007]

On 1/28/2020 at 9:09 AM, aggiegeog said:

GFS ensembles getting somewhat interesting for next week with a ridge off of the West Coast and an upper low moving into TX from the SW. We are in a very El Nino like pattern so nothing super cold but we just need temps in the mid 30s for snow with an upper low doing the rest.

I'm expecting lots of cold rain

[raindancewx]

Elephant Butte Lake is already the fullest it has been since 2010. Currently 585,967 acre feet of water in the lake. Last day with more than that? June 18, 2010 (586,945 acre feet).

The highest value for 2010 was 604,248 acre feet, with 2009 peaking at 705,284 acre feet. I don't think we'll beat 2002 - which peaked at 905,744 acre feet. I'm expecting the lake to get into the 640,000-740,000 acre feet range sometime by the end of July.

[aggiegeog]

On 1/29/2020 at 2:33 PM, cheese007 said:

I'm expecting lots of cold rain

That is most likely obviously but now at least official forecasts for N TX are starting to include snow or a mix for Wednesday. Models show the same. Anything from low 50s and rain to low 30s and snow are possible.

[aggiegeog]

Hints of a significant snow now for Wednesday. Enough surface cold, plus a very strong upper level trough. We have not seen this in a long time. I am not going to be very optimistic until Monday though.

[cheese007]

19 hours ago, aggiegeog said:

Hints of a significant snow now for Wednesday. Enough surface cold, plus a very strong upper level trough. We have not seen this in a long time. I am not going to be very optimistic until Monday though.

Looking like it's gonna stay NW of the metro per FWD. Again

[aggiegeog]

I am just excited for a storm with boom potential of a foot vs best case 3 inches. Get a bit stronger surface high and get the trough to dig further SW then it goes from an western NTx storm to an area wide blizzard. It is so nice to have a big one to watch. Shades of 09/10.

[cheese007]

Might hit 80 tomorrow and then snow Wednesday. Peak Dallas weather. On a related note, NWS shifted precip southeast but I'm trying not to get my hopes up lol

[Sydney Claridge]

GFS seems quite the outlier right now, depicting a major snowstorm over the north Texas area (especially just west of DFW) on Wednesday.  Most other models (NAM, Euro, etc.) are further north.

[cheese007]

54 minutes ago, BrandonC_TX said:

GFS seems quite the outlier right now, depicting a major snowstorm over the north Texas area (especially just west of DFW) on Wednesday.  Most other models (NAM, Euro, etc.) are further north.

How much further north? Dunno where to access models

[DFWWeather]

1 hour ago, BrandonC_TX said:

GFS seems quite the outlier right now, depicting a major snowstorm over the north Texas area (especially just west of DFW) on Wednesday.  Most other models (NAM, Euro, etc.) are further north.

Yes, but all of the GFS ensemble members output snow/ice for the area and over 50% of the both the 0z and 6z ensemble ECMWF members also produce significant accumulations of snow/ice for the area as well as a majority of Canadian ensemble members. The deterministic GFS is not an outlier in that respect. This is something to really watch. None of the models have done well with cold air this winter season at all and the trend here is colder. The 500mb pattern is one favorable to produce significant to even major snow/ice events in North Texas. The question is moisture/lift at the time of the coldest air and how cold the air will be. With it being nearly 80 today, temps will need to be in the 20s for this to really stick to the roads. Some models have us in the 20s for the event. The NAM is discouraging as it is cold enough, it just dry slots us, however it is know for being too dry in that time range. This is certainly the best setup I've seen in years for us.