Stx_Thunder

It is warmer air advection (not necessarily moisture) due to a southwest/southerly flow usually in the 850Mb - 700Mb or 5 - 10 Kft layer overrunning colder air closer to the surface, causing the advecting cloud deck usually from the western Gulf. Which is common at least in the southern part of state whenever there's a trough out west, and we already have a polar or arctic airmass in place. This was earlier today (15z or 9 am) on Dallas/Fort Worth (FWS) site radar. Showing southwest flow from about 6 Kft or 6,000 Ft (just above 850Mb layer) and up:

Current VWP & 12z upper-air obs this morning in STX already showing a fairly strong southeasterly LL flow (20 - 30 knots up to 850Mb once again like prior to the last major overrunning precip event), with low-level WAA cloud deck firmly in place now looking outside here, now that it's daylight. And areas/bands of light (all liquid) rain developing near lower coast around Brownsville.

The 'possible strong event' topic tag seriously needs to be taken off here as there's basically a 99% probability now the current La Niña phase is going to remain weak, then likely go back to neutral ENSO going into spring. It was only just about a month ago Niña went official, and was already projected to be a weak Niña on dynamical models even back in November. I should also point out, CPC did a poor job with the forecasting. Insisting La Niña would return by the summer last year (which did not happen at all).

GFS & Euro were already projecting decreasing cloud cover N - S in the state through the day Tuesday. Which obviously explains why 40s are starting to show up that day now too. Good you agree on the wild model forecasting because it definitely has been around here since 2025 started. I've never seen such crazy/complicated projections. Especially less than a week out. 'Already makes me wonder how they're going to be like for severe season come spring. 'Would not trust the mesoscale models (except maybe NAM in these winter wx scenarios), as they always have a lot of precip & convective intensity bias around here. Plus, latest 0z GFS tonight is starting to speed up LL drying on Tuesday. Which is definitely plausible, given the strongly reinforced continental north CAA flow by Monday night verifies.

40s showing up in ETX even Tuesday afternoon now on 12z GFS today.

I kind of doubt there's going to be any real snow accumulation with sfc temps hovering around (even above) 32 F, and such un-realistic 850Mb temp projections in ETX, Tuesday. Looks more like a sleet event, and ice storm in SETX. After this week, that looks to be it for any more real Arctic air intrusions for the rest of the season looking at the CFS. Even GEFS & EPS projections are going warmer (than things have been lately) into February. AO is also really starting to trend in a positive phase as well going forward.

Overall, this next Arctic air intrusion is just going to be a glancing blow.. with 40s back on the maps by Wednesday (which I'm not surprised anyone has mentioned here yet). Even in NTX (possibly even Monday too in CTX), on both GFS & Euro. And even on NAM. Which handles these polar/arctic air intrusions the best. And with the AO having already been in a positive phase to now, I can 100% say with confidence it's certainly not going be anything like the 2021 chill (like some were alluding to here.. because of the crazy as usual Canadian output. I guess...). Even Canadian itself has finally started to back off on its absolutely insane junk temp projections from the past several days or so. Except on Wednesday morning lows. Still going down to < 0 F not far north of Houston... The well-below freezing 850Mb temp projections on GFS & Euro also do not look realistic to me. Since even both of those reliable globals are showing the core of the coldest air has trended well northeast over the Great Lakes region. So I doubt there's going to be any real snow accumulation early this week in ETX/SETX. That's about the only winter wx that's actually going to be worth watching for this "outbreak" going into Tuesday morning. I'd be lucky to even see Sleet coming down here in STX (away from any FZRA potential).

Would not count on it. AO (Arctic Oscillation) is trending back to + phase for later January. Just FYI.

DFW still reporting light snow as of 5:00 am. Starting to see some enhanced echos develop on base radar right now in & around the metro area, moving east.

Seeing that shifted northerly flow now on Dallas VWP radar and surface obs, up to 3 Kft. 'Doesn't look like too much more to go around tonight though for the rest of this winter wx event.

CAA coming back in the LLs by mid-evening into the area. Just as I wrote in that earlier post.

Not when it's southeasterly in TX (out of the Gulf) in the lowest levels because it definitely both warms & moistens, decreasing wet-bulbing a lot faster than if southwest. I definitely saw that in action today. That was really the 'monkey in the wrench' in this setup. Overall, this whole winter wx forecasting scenario has been nothing short of interesting. No one really knew how it was actually going to pan out. Main thing is, it did not turn out to be a dismal rain-only bust around DFW.

Believable, as that northerly reinforcing low-level CAA surge is showing up now on the western hill country VAD wind profile (SJT, DYX radars).

Still got a notable east - south flow at the surface up to 4 Kft on Dallas VWP radar, with obvious influence still coming from the Gulf Low moving up the TX coast right now. The warm-rain process will likely continue over DFW into this evening. I do see a deeper northerly LL flow has developed on VWP radar right now further southwest in San Antonio (EWX radar). They're not far from the freezing mark either with rain still ongoing (37 F). CAA isn't likely to ramp up in DFW area until mid-evening, at the earliest.

DFW metro now sitting just above the freezing mark (33 - 34 F), reporting just rain in parts of Fort Worth. Icy road reports still piling up around there on Drive Texas map. Not sure why Dallas NWS hasn't posted any FZ rain or icing LSRs from around there yet (still only snow ones).

It was already a very notable factor on models for this event ever since people here got excited about an all-snow event some days ago around DFW. Though I wouldn't say the snow potential is a lot less now as both 12z GFS & Euro today are still in pretty good agreement on CAA returning earnestly by later tonight. Pushing LL temps below freezing pretty quickly in the area. Moisture would likely stay around until at least Friday morning with this more south-southeasterly Gulf-influenced flow. Dallas NWS also still noting a lot about the snowfall potential over NTX tonight in their 3 pm AFD update.

Fort Worth area has been reporting FZ rain for a few hours now & sitting at 32 F and DP not much lower at all anymore. Already seeing lots of icy condition reports on roads/highways in DFW on drivetexas.org. Dallas VWP radar has a southeasterly flow of 20 - 25 knots now in the first 3 Kft above the surface. Would expect the icing to continue there in the metro at least until this evening. Things are starting to get very interesting there today. Just like I suspected these past couple days. I did not agree at all with this early morning's Dallas NWS meteorologists who said icing accumulations were just going to be "light" in the area.

Pretty much what I'm expecting it to be in DFW tomorrow. A real winter precip battleground that's going to be extremely interesting. Which I'm sure does not happen often there in NTX. Could get very messy though with all the low-level WAA, and then the snow coming & packing it in Thursday night. I just read the latest Dallas/Fort Worth NWS forecast discussion and even the meteorologist (Shamburger) who wrote that evening update a couple hours ago is fascinated by this setup. This is definitely going to be one to note in the wx forecasting books as it's been challenging to figure out how it's all going to pan out around DFW since last week.

Canadian always overdoes pretty much everything (including hurricanes), so I never rely on it. Mesoscale models also (except NAM for mainly surface temps in these polar/arctic air masses). 12z runs usually give the best insight overall from my experience. At least on globals (GFS, Euro). Euro overdoes things to an extent (convective events/intensity also). Especially when the event is close lately, but never crazy most of the time. With tomorrow's event, I'm looking at GFS the most because it's been performing the best lately with these winter wx scenarios in this part of the country. Though I normally rely more on Euro.

I never said "no snow" in DFW lol My intention here was just to point out why the whole event was not going to be just snow around there from the beginning because of the LL warming factors. Which has basically made the DFW area a winter precip battleground tomorrow. And what got me hooked on this. But yes, more sleet & probably higher FZRA threat Thursday. Which is much more interesting to me. While I don't think it's really in the cards, can't rule out a dismal rain for a short time in the metro. Though, I also don't think you snow addicts on here have too much to worry about because CAA in the LLs returns earnestly by later Thursday night up there. All models seem to easily agree on that.

Wondering what exactly do you mean by that Charlie Brown reference (assuming it is from that)..?

The trend in the more reliable models is still warmer in the LLs further north. I'm even seeing today's 12z Euro is starting to go in that direction as well up in DFW area. Which was the most pessimistic on the warming the past several days and kept showing more snow. And I agree with @Chargers09 that the models usually do underforecast the strength of these WAA patterns in TX this time of year. Particularly with these much more dynamic incoming systems out west. Either way, I'm already seeing the evidence of a stronger WAA regime on Brownsville (BRO) VWP radar right now.

In winter wx forecasting, a +3 C LL layer can actually make a big difference in precip type at the surface. Even if it's below freezing at surface. Today's 12z GFS has actually come in a little warmer at 850Mb around DFW because of the projected deep, large scale south-southeasterly over the eastern half of state (keyword: southeasterly) WAA flow until it cuts off Thursday night. Showing even above 0 C spots now creeping into DFW. It's already been quite consistent on that the past several days on the 0 C area hovering over the area. So I'm confident it is not going to be all snow, daytime Thursday at least in DFW metro - southeast. 0z UA obs this evening even shows 850Mb temp is already right next to 0 C. And above freezing now north of Houston (3 C red dashed line). The LL warm-air advection regime has already started here in STX as I'm already seeing a fairly strong southeast flow near 30 knots at 5 Kft on Brownsville VWP radar right now.

Not seeing any real thermal differences and I trust the 12z runs more from experience. 850Mb 0 C line is still way too close over DFW for all-snow comfort until later Thursday night. Should also note 700Mb 0 C line also still quite close on both runs as well.

Both today's 12z GFS & Euro trending on a slower approach of the H5 Low out west and consistently still quite potent & large. This could easily allow for longer/deeper low-level WAA over the eastern part of state as the Gulf Low is likely to track more northward up the coast instead of offshore. With a fairly strong southerly LLJ (possibly 50 knots in STX which is definitely plausible in this scenario but could be even stronger as I've seen in past years, this time of year). While not likely, it's definitely worth noting Canadian wants to bring the 850Mb Gulf circulation further inland over ETX Thursday night on today's 12z run. WPC now even has a marginal excessive rainfall risk posted for mid-upper coast for possible 3 - 5 in. rain totals Thursday - Friday morning (Day 3). Which would 100% be above normal for this time of year in such short duration. --- 850Mb temp even now on DFW 0z UA obs this evening is only around -2 C (-3 this morning) per SPC data with above freezing values not well south either. All in all, it's pretty safe to say now it will not be an all-snow event in DFW. Moisture should not be an issue around there in this scenario with the large-scale and fairly deep WAA regime over the eastern part of state. And it's definitely keeping my eyes pinned on that up north way more than the coastal & possibly even up to ETX heavy rainfall threat (again there) around me. Even thunder potential over all coastal region which SPC noting on D3 outlook. Which I wouldn't rule out a supercell or two near the upper coast with 60s DPs coming right next to the coast (even upper 60s not far offshore) on both GFS & Euro, with such a very dynamic system out west. Which I still don't think many here realize.