DFWWeather

From FWD: Heavier intensity precipitation will start after dark and should primarily be sleet. We'll continue with moderate sleet from 02Z through the overnight, however there is some concern that we could see a quicker transition to snow if lift is stronger than anticipated. If that occurs, then snow could be heavy at times. For now, we'll continue to monitor this and carry a snow/sleet mix after 10Z with a transition to all snow by 14Z. Precipitation should start to taper off around midday Sunday. Overall the vertical column has been cooling much quicker than models have forecasted. If we can get the change over to snow and with temps in the teens tonight snowfall ratios will be extremely efficient. Even if it stays sleet your looking at 4:1 or even 5:1.

Metro may be primed for more snow this evening with 20:1 ratios looking probable as temps will be in the teens shortly.

Arlington side roads now completely iced over. KDFW down to 21 and getting moderate to heavy sleet.

KDFW now down to 23°F racing toward the teens. Grass starting to get covered in sleet. The second wave tonight may producer way more snow than thought and higher end ratios. Any thoughts? I can say we are out of the heavy ice/freezing rain accretion zone.

Absolutely, this will be a sleet dominate storm. There could be 0.10 to 0.25 ice accretion. I'm more concerned with higher sleet totals than what FWD is advertising, especially with the potential for thunder sleet or convective sleet. There should be some snow on the back end as the entire column cools.

I have a feeling the 1 to 3 inches of sleet forecast by FWD might be a tad underdone given what I am seeing in the models and the potential for convective sleet.

Very interesting read on afternoon AFD from FWD, discussing thunder sleet.

12z 3km NAM is burying KDFW in 5 to 6 inches of sleet.

Today's 0z data came in quite a bit warmer overall. Looking back at POR and reconstructed anecdotal data back to 1785, there has never been two subzero readings at DFW in a five year window. That would be unprecedented if we did. That is a 25 to 30 year outcome at best. So my expectation is that we stay at 5 or above at coldest point Monday for KDFW. Still respectable cold though, but still acknowledging a non-zero risk of falling below 5. Colder spots could get that cold. Despite many forecast, we are not going to get above freezing on Monday if we start that cold with significant snow/sleet, especially with a northerly wind component. So significant improvement may not be had until Tuesday afternoon and even then I think we will stay below 40, so risk of problems Wednesday morning from refreezing is likely if we get at least 3 inches of sleet. NAM is burying us in 5 to 6 inches of sleet, but I think it is missing the change over to snow on the back end.

12z GFS showing 0 at KDFW and ICON showing -2 and Canadian at 1

Norman has upgraded their FA to a Winter Storm Warning. I'm sure other offices will follow sometime today. Most guidance is clustered around ~2.00 QPF for DFW. FWS has upped its ice accretion to 0.25 to 0.50 and over east Texas 0.75 to 1.00. This is squarely in Ice Storm Warning criteria and I wonder if that is where they are leaning for part or all of the area. I still think for DFW sleet will be the predominate precipitation form.

Actually, the upper low is slowing down a bit and models are converging on that. FWD NWS is upping their timing on the cold air and beginning impacts in the afternoon Friday. This still looks like a predominately sleet storm with snow on the back end. An Extreme Cold Watch has also been issued.

Diving into this morning's 0z data. It is even colder, now suggesting DFW could potentially stay below freezing through Wednesday or Thursday next week with potential another shot of Arctic air on Friday. QPF has increased across all modeling. Single digits are a lock and Monday morning could be 0 to 5.

Not exactly...Just to clarify the terminology a bit...when meteorologists talk about a ‘dry slot,’ they’re referring to the dry conveyor belt wrapping into a mature cyclone. It’s a broad synoptic feature that shows up in global mass fields and satellite water‑vapor imagery. It’s not something the NAM typically resolves well at the end of its run, and the model actually has close to an inch of QPF down by midnight Fri/Sat, which suggests a fully intact precip shield rather than a dry slot intrusion. About the analogs I posted earlier: When I mentioned Feb 2003 and Dec 2013, I was referring to the H5 pattern and overall pattern structure, not the exact surface impacts. Those events share several large‑scale similarities with this setup: 1) A deep, well‑established Arctic air mass 2) A southern‑stream disturbance ejecting from the Southwest 3)Strong overrunning and isentropic lift 4) A marginal warm layer aloft that cools with time 5) A broad, long‑duration precipitation shield Dec 2013 did produce some icing, but the event was actually sleet‑dominant because the warm nose was shallow and weak. That’s why it’s a useful analog here — the thermodynamic structure favored sleet, and this system is showing a similar profile so far. So the comparison isn’t about matching the exact precipitation type outcome — it’s about the larger‑scale pattern and storm mechanics. From that perspective, the analogs line up pretty well.

FWD has also place its entire FA under a Winter Storm Watch. The chance of temperatures getting to 5 or colder with this event, even in the heart of the Metroplex has increased markedly. The majority of all ensemble members show temps now in the single digits as do the operational models. NBM now is down to 10°F. I fully expect Extreme Cold Warnings to go up with this.

Good analogs to this event synoptically are Feb 2003 and December 2013 with this event producing potentially more QPF and a much colder and denser Arctic airmass entrenched. The H5 pattern is one of the 4 classic setups that gives North Texas significant snow/ice. This will likely be a sleet maker initially with snow on top, and I wouldn't even rule out some freezing rain accretion at start. I do expect the change over to be quicker timing than currently advertised by FWD, probably more late morning early afternoon on Friday. We'll know a lot more when in range of the NAM. Too early to try and call accumulations right now with precip type and phase changes unknown at this range.

Here was my post from the other thread. For DFW, we are looking at a major winter storm this weekend with all models and their ensemble suites predicting a mind blowing 2 plus inches of QPF in solidly subfreezing air. If this verifies anywhere remotely close to that, the Metroplex will be totally shut down. In addition, the threat for severe cold (10 or lower at DFW) has increased significantly with most models and their ensembles clustering around 10 to 15F on average. There is a ~1050 to 1055mb Arctic high parked in the Dakotas bleeding cold air into the northern half of the state.

Yes, quite an interesting turn of events. FWD NWS wording this morning in their AFD was some of the strongest wording I've ever seen for day 5/6 potential event. Remarkable that the NBM has 1.5 inches of QPF. I'm not ready to go as cold as you yet, but I absolutely think severe cold (i.e temps 10 or colder) is on the table, especially if we get snow and ice. Regardless, if we get over an inch of QPF with temps in the teens and 20s would make for quite the winter storm! Our record warm winter is about to be turned around. I can't help but also see another surge of Arctic air around Feb 1.

Officially the low was 23°F at DFW Airport this morning. It was also 31°F yesterday morning, both lows beat the forecasted lows. Things could get quite interesting after ~ Jan 24th. We have a predominately negative EPO, WPO, AO with positive PNA. Displaced polar vortex at 50 mb down to southern Hudson Bay. MJO->7->8->1->2. Severely cold in Alaska, NW Territories, and Siberia. Strong blocking looking to develop over the top and a strong ridge over Alaska. This could set the stage for a significant dump of Arctic air into the CONUS and given the position of the ridge, Texas. Models starting to catch on to this idea. Significant signal in the majority of ensemble members of the Canadian, GEFS, and ECMWF. H5 pattern on ICON strongly showing a signal about this time. Our warm winter may be about to be turned around (hottest on record up til now).

DFW Airport has not fallen below 60°F yet this fall. Looking ahead at the models, it might not do it before the 25th of October. This will make the latest on record by a wide margin for the temp not to fall below 60°F. 2025 for DFW is also shaping up to be among the hottest falls on record, unless something drastically changes in November. Having looked at the top ten hottest falls on record, the following winters were warm in every single case. Needless to say, October will also be among the hottest on record for DFW. Looking at the hottest Octobers on record, we have a mix of very warm to very cold winters that followed. 1963-64 was one of them which was one of our coldest winters. If the intense warm SSTs in the Gulf of Alaska hang around for winter, that can promote ridging over the state of Alaska which can send intense Arctic shots down into Texas. A neutral to weak La Niña is also expected. Some of our coldest weather has occurred during weak La Niña events. The other interesting thing is the intense stratospheric warming event that occurred over the south pole in September. Those often correlate well with colder winters in the Plains of North America. Given the preponderance of data though, it does appear that winter will be warm overall for DFW.

I'd be curious to hear everyone's input on this, especially those that know what is going on with the weather models. For the last 5 to 8 years, I have been noticing a pronounced trend in the models high temp forecasts to be excessively too hot. This is particularly evident in the summer time high temps for DFW. The operational GFS is the worst, in fact so bad, I have to throw its numbers out beyond day 3 when forecasting. To be clear, I'm talking about the raw numbers of the model itself not the MOS numbers. The raw GFS numbers can be as much as 8 to 20 degrees hotter than what actually verifies. It consistently forecasts high temp values above 110°F, sometimes as high as 120°F plus. First off, the hottest temp ever recorded here is 113°F, and we have only been 110°F or warmer 14 times out of 125 years of records. So that is absurd! If I had to pick a model to forecast summertime temps for the DFW area, it seems the Canadian ensemble average is the closest to what actually verifies. The ECMWF was a close second until this summer. It has now skewed warmer. This summer all of the models tend to want to forecast temps into the 100s when there is no valid reason for that if one looks at the pattern and conditions. Our normal temp in the height of summer is 97°F. Current forecasts I have seen for DFW over the past several days have been 2 to 5 degrees too hot than what verifies. The NBM numbers are also being skewed too warm because of this. So what is happening?

I apologize if I have upset you, but you absolutely did say no more Arctic air for the rest of the season. See your post above from Feb 4th. All I did was disagree with you. I use the word 'extreme' because that is the term the NWS uses. The Extreme Cold Warning is not just for wind chills, it is also issued for the prolonged duration of subfreezing temps, and the threat of temps falling to 10 or lower or for high temps failing to reach 20. For our area, the latter is considered severe cold. In this case, there is a threat some areas around the DFW Metroplex will get to the single digits with this and for a prolonged duration subfreezing temperatures, not to mention wind chills as cold as 10 below zero. I was just pointing out that not even South Texas is escaping the cold. Anytime it freezes in LRGV it is a big deal. That is why Marshall J. McFarland came up with the McFarland signature that recognized prominent 500mb pattern features that lead up to freezes deep into Texas. The key to getting Texas cold is the position of the west coast ridge, if it is along the west coast, or off-shore up over Alaska. The latter has historically produced some of Texas' biggest cold shots and is a key element in the McFarland pattern. Though the current outbreak was not a result of a McFarland.

I guess we just have a different idea of what "extreme" cold looks like for DFW. The NWS has issued an Extreme Cold Warning for the area. Temps are not forecasted to get above freezing until Friday with a shot of getting below 15°F on Thursday morning and wind chills below zero at times tonight and possibly tomorrow night. Subfreezing temps all day this late in the year is quite "extreme." We are talking temperature anomalies of 25 to 30 below normal for a couple of days. I do not know what else you need to have...Feb 2021? What happened in Feb. 2021 is a once in 30 year event in DFW. You said before we were done with the Arctic air for this winter. I said the pattern would deliver, that cold air loves to push in this type of pattern, that it would likely be DFW's coldest air of this winter, and that is exactly what is happening. I might also add they are expecting freezes in the LRGV with this. Freeze Watch in effect for Laredo, Tx right now over to Corpus.

This is not a glancing blow of Arctic air with a ~ 1050 to 1055mb high building down the plains. This is a direct shot. KDFW has a the potential at getting below 15°F with this on Thursday morning with windchills dangerously cold for North Texas. The NWS has issued a Extreme Cold Watch which will likely get upgraded to a warning. I agree precip will be light, but there is a signal in the models for freezing drizzle/mist beyond 4pm Tuesday into early Wed with temps falling well down into the 20s. KDFW is forecast to remain below freezing for at least 36 hours. The deterministic GFS is out to lunch on temperatures and has been performing terribly all winter long for DFW, and doesn't even agree with its own ensembles which are in the teens for KDFW. I think that model just cannot see cold air anymore and there is an extreme warm bias to it. Do not disagree that March may be on the colder side.

This pattern is one that doesn't typically bring North Texas a lot in the way of wintry precipitation. Looking at latest 12z data on all the models, there seems to be a trend of the wave moving east rather quickly being drier overall. Thus, whatever falls will be very light, but I'm starting to think it won't be much of anything. I don't see the type of cold you are talking about without decent ice/snow on the ground, and none of the models suggest amounts would be that much. I think DFW has a shot of getting below 15 with this, maybe down to 8 to 12 with a bit of snow/ice, but it won't anything like 2021, at least for DFW. 10 degrees would necessitate an Extreme Cold Warning for our area though.