Texas Winter 2024-2025

[Portastorm]

Also don't forget models have been zoning in on a 2nd system the end of the week behind the first one.

I saw that around the Friday time frame. Do you think we will have enough arctic air remaining?

It'll be marginal older cold. Orangeblood likes to reminds us there's typically a front end storm and a back end storm with the air mass exchange.

Yep, considering the potential pattern re-load ... I think we're just in the early innings of a 9-inning ballgame.

[wxman22]

Big difference at the surface between the GFS and CMC.

[orangeblood]

I saw that around the Friday time frame. Do you think we will have enough arctic air remaining?

It'll be marginal older cold. Orangeblood likes to reminds us there's typically a front end storm and a back end storm with the air mass exchange.

Yep, considering the potential pattern re-load ... I think we're just in the early innings of a 9-inning ballgame.

If you want Texas cold and snow, this 5 day average Canadian run at 500mb is what you want....couldn't draw it up much better!

[TomballEd]

NWS Brownsville

A cold front with air derived from the arctic will arrive on
Saturday and we will have a McFarland clone (referring to the
classic 1976 paper by M.J. McFarland describing a synoptic setup
that produces unusually cold weather for deep South Texas). Once a
cold front moves through, the mid-level trough axis from Hudson
Bay southwest across the United States with a north-south blocking
ridge to the west allows very cold air to plummet south through
nothing but barbed wire fencing over the Plains. The resulting
"signature" is often present when extreme cold devastates local
agriculture, especially when that industry was of major
importance.

Temperatures will "free-fall" starting Saturday night creating a
winter weather threat that will persists through much of the
week. Though initially dry, cold air nosing south into the CWA
will dance with warmer and moister marine air to set up a
deepening coastal trough. That will enhance rain chances and, when
combined with the colder temperatures which are expected to reach
a nadir Wednesday and Thursday, will up the chances for pockets
of wintry precip.

Used an NBM baseline for the forecast, realizing that there is
still a lot of uncertainty. Some of the models (like the NAM)
handle the colder temps better, and those have yet to come into
prime range. For now, the ECMWF and the NBM50 seem to be tracking
well. A bit concerning is that the lower end NBM probabilities (25
and 10 percent) which might be considered reasonable worst case
scenarios, take temps well below freezing for the coldest
nights/mornings. For now, however, we are looking at freezing
temps (around 32 degrees) for the Ranchlands Monday morning, a
light freeze across the northern tier and Starr Counties Tuesday
morning, and a light (possible hard) freeze for that same area
Wednesday morning along with a light freeze reaching Hidalgo,
Willacy, and northern Cameron Counties.

For us old-timers, the phrase "McFarland Signature" is an attention-getter! As some of you wrote about yesterday, once the NWS Brownsville office used that phrase, you knew that a heckuva cold blast was coming down into Texas. So to see reference to this again certainly raises a few eyebrows. Reference to that phrase also meant that it wouldn't be a one-day-and-done kind of thing but a more prolonged cold snap.

IMO the globals won't latch on well to the temps for next week until this weekend. We know what's coming per the ensembles and the general pattern set up. Now it's time to fine tune the temps and precip chances.

Someone posted a 500 mb forecast yesterday, and I said it looked very McFarland (a deep trough from near Hudson Bay extending well SW) and mentioned I had not seem McFarland in a disco in a while. Its back. New post above is very McFarland.

[TomballEd]

GFS is slowly backing off on snow amounts. Texas Snow Weenie Suicide Watch could be issued soon. Anyone have ensemble snowfall?

[Rgv20]

NWS Brownsville

A cold front with air derived from the arctic will arrive on
Saturday and we will have a McFarland clone (referring to the
classic 1976 paper by M.J. McFarland describing a synoptic setup
that produces unusually cold weather for deep South Texas). Once a
cold front moves through, the mid-level trough axis from Hudson
Bay southwest across the United States with a north-south blocking
ridge to the west allows very cold air to plummet south through
nothing but barbed wire fencing over the Plains. The resulting
"signature" is often present when extreme cold devastates local
agriculture, especially when that industry was of major
importance.

Temperatures will "free-fall" starting Saturday night creating a
winter weather threat that will persists through much of the
week. Though initially dry, cold air nosing south into the CWA
will dance with warmer and moister marine air to set up a
deepening coastal trough. That will enhance rain chances and, when
combined with the colder temperatures which are expected to reach
a nadir Wednesday and Thursday, will up the chances for pockets
of wintry precip.

Used an NBM baseline for the forecast, realizing that there is
still a lot of uncertainty. Some of the models (like the NAM)
handle the colder temps better, and those have yet to come into
prime range. For now, the ECMWF and the NBM50 seem to be tracking
well. A bit concerning is that the lower end NBM probabilities (25
and 10 percent) which might be considered reasonable worst case
scenarios, take temps well below freezing for the coldest
nights/mornings. For now, however, we are looking at freezing
temps (around 32 degrees) for the Ranchlands Monday morning, a
light freeze across the northern tier and Starr Counties Tuesday
morning, and a light (possible hard) freeze for that same area
Wednesday morning along with a light freeze reaching Hidalgo,
Willacy, and northern Cameron Counties.

For us old-timers, the phrase "McFarland Signature" is an attention-getter! As some of you wrote about yesterday, once the NWS Brownsville office used that phrase, you knew that a heckuva cold blast was coming down into Texas. So to see reference to this again certainly raises a few eyebrows. Reference to that phrase also meant that it wouldn't be a one-day-and-done kind of thing but a more prolonged cold snap.

IMO the globals won't latch on well to the temps for next week until this weekend. We know what's coming per the ensembles and the general pattern set up. Now it's time to fine tune the temps and precip chances.

Someone posted a 500 mb forecast yesterday, and I said it looked very McFarland (a deep trough from near Hudson Bay extending well SW) and mentioned I had not seem McFarland in a disco in a while. Its back. New post above is very McFarland.

NWS Brownsville still references the McFarland signature on their discussions. Our local TV Met also mentions it as here in the RGV it is a very strong and reliable indicator of Freezing Temperatures down here.

.LONG TERM...
(Wednesday night through Monday)
Issued at 320 AM CST Tue Jan 14 2025

There will be a lingering chance for precipitation tomorrow night as
the ongoing coastal low continues to bring moisture onshore (20-40%
chance east of I-69C). On Thursday an upper-level shortwave pushes
the coastal low off to the east and out of the area, which will
sharply decrease chances for any precipitation, though areas along
the coast could still see a shower or two. Conditions will be dry
Friday through the weekend, but skies will stay mostly cloudy and
winds will turn southerly.

A strong cold front is expected to pass through Deep South Texas
later Saturday into Sunday, bringing another round of arctic air
into the region. Current guidance is showing that this particular
system is taking on a McFarland shape, which is a notorious
troughing pattern for effectively bringing much colder air to the
Rio Grande Valley, with the potential for freezing low temperatures.
No precipitation is expected with the frontal passage itself, but
rain chances could return early next week in the wake of this cold
front, as another inverted coastal low may develop offshore.

[WacoWx]

Sorry about that. Was just posting my story.

I was just trying to be funny...and I'm jealous.

[dhweather]

12Z GFS lost the snow for NTX, lets see what Jester says.

[MississippiWx]

Last 3 runs of the GEFS seems to be digging/holding back energy more so than the operational. Maybe the GFS flip is coming.



Edit: may have to click on the image to see the gif.

[CaptinCrunch]

January by the numbers at DFW Airport through the 14th

AV High - 51.4
AV Low - 31.1

AV Monthly - 41.2
Dptr from normal -4.8

10 Freezes
2.6" of snow/sleet

[Tireman4]

GFS is slowly backing off on snow amounts. Texas Snow Weenie Suicide Watch could be issued soon. Anyone have ensemble snowfall?

You know models will flip flop every run up until the event. The best timeframe would be 24-48 hours before the event. To quote the HGX NWS..

"The main takeaway is that we now have medium to high confidence (40-
50% chance) that wintry precipitation will occur over southeast
Texas during the first half of next week. All winter precipitation
types are still on the table right now, but broadly speaking
guidance and the NBM seem to still favor snow as the dominant precip
type. Areas north of the I-10 are more likely to see snow/mix of
sleet. Areas to the south may see a mix of snow/sleet/freezing rain
and potentially liquid rain right along the barrier
islands/nearshore waters. As for how much snow/sleet/ice,
uncertainty is too high to put a specific amount on it just yet.
Broadly speaking, it`s more snow to the north and more ice to the
south. We`ll have a better idea of "how much" over the next few
days, but for now we should prepare for some accumulating winter
precipitation."

[Iceresistance]

Think the Canadian might be a big storm run (compared to GFS) since it digs more.

I have also noticed very high model uncertainty for this weekend

What we do know is that extreme cold is coming

What we don't know is how cold we could get and if there will be snow involved

The trend has been to slow down the upper level features.

I have noticed the GFS has the progressive bias

[Stratton23]

12z Euro looks more like the CMC with no suppression, lots more moisture to work with

[Throckmorton]

Where did the record smashing Arctic air for Austin go? The very high air pressures will be there....

According to the GFS operational model (Jan. 15th, 12Z run), here are the forecasted temperatures, pressures, and snow for Austin Camp Mabry:

59–42...Saturday, 1/18
43–32...Sunday (1033 mb)
45–29...Monday (1035 mb)
36–28...Tuesday (1044 mb) (snow; 2.4 inches)
39–26...Wednesday (1040 mb)
49–38...Thursday (1024 mb)
49–37...Friday
51–33...Saturday, 1/25
61–40...Sunday

And just for fun, here is the Australian ACCESS–G model's forecast for Austin Camp Mabry (Jan. 15th, 00Z run):

58–42...Saturday, 1/18
42–32...Sunday (1028 mb)
37–29...Monday (1029:mb) (snow; 0.4 inches)
38–30...Tuesday (1040 mb) (snow; 0.4 new inches)
48–27...Wednesday (1040 mb)
52–32...Thursday (1032 mb)
46–43...Friday, 1/24 (model run ends at 6 pm CST)

[wxman22]

Yep the Euro looks like the Canadian but with lighter precip.

[Stratton23]

Agaib ill say this, the GFS is likely going to be too warm with temperatures with snow/ ice becoming more likely now, this happens every single time with an arctic/ siberian air we have had in the past, GFS Is good with a lot of things, but surface cold, its absolutely terrible at seeing

[Lagreeneyes03]

Also don't forget models have been zoning in on a 2nd system the end of the week behind the first one.

Isn't that the one that gives DFW more of a chance, we've gotten shafted in DFW proper (Dallas and Tarrant counties, anyways) for the past few years. Nothing more than 3 in at a time.

[Ntxw]

Yep the Euro looks like the Canadian but with lighter precip.

https://i.ibb.co/7JNNZNT/IMG-0168.png

https://i.ibb.co/b7mm9fg/IMG-0169.png

That's a not so fun ice storm event for I-10. Temps are in the upper 20s with it.

[Stratton23]

Interesting Euro run, 2nd piece of energy behind the main system beings another round of light wintry precip to central texas, and then potentially a third system brings yet another mixed bag of precipitation beyond that, all in a 10 day period

[Ntxw]

Also don't forget models have been zoning in on a 2nd system the end of the week behind the first one.

Isn't that the one that gives DFW more of a chance, we've gotten shafted in DFW proper (Dallas and Tarrant counties, anyways) for the past few years. Nothing more than 3 in at a time.

I wouldn't call that shafted . That's more than the yearly average, and much more than anything from 2016-2019, a few have been under expectations for sure yeah.