Sydney Claridge

And SPC drops the lower Ohio valley from an Enhanced risk all the way down to a Marginal risk for the Day 2 outlook, trimming back the ENH to just north of Memphis, TN.

NAM is trending weaker and further south over the last few runs, affecting the anticipated moisture return in the lower Ohio Valley and moving the warm front location closer to the Ohio River. It's not much further south, but a weaker storm would lower the potential for severe further north whereas a stronger storm further to the N or NW would allow for more moisture return. Beyond the range of the NAM, it seems that many of the models are suggesting a "Freshwater Fury" storm with pressure dropping to near or below 980 mbar over Ontario. The GFS and GFS-FV3, plus the ECMWF, are displaying a system below 975 mbar. If this storm were to bomb before reaching the Lakes the severe potential would likely be even higher. I would expect the strongest storms to be in the eastern part of my sub (AR and LA) and also W TN and W MS by the looks of things, though. EDIT: SPC is now saying that E AR, the western 2/3 of TN, N MS, and the western half of KY (up to a point SW of Louisville) will be in a Day 3 Enhanced risk at the 30% hatched level; this also includes small slivers of SE MO, S IL, and S IN along the Mississippi and Ohio rivers.

NE Texas is in the Day 6, so they might get involved it seems. Like you said, barring a westward shift, north-central Texas and DFW probably will not be involved. Seems like a potential western Dixie and mid-Mississippi/Lower Ohio valley event based on the SPC outlook thus far.

I was noticing that on the model runs as well. What are the probabilities that north-central and NE TX gets involved here? (though it's probably a bit early to say) Today's 12z and 18z GFS runs are at least hinting at the idea (though somewhat earlier in the day), but that is just two runs of the same model. The potential event is still over a week out so the models will definitely become more refined as it draws closer, and perhaps more questions can be answered then.

I cannot help but notice that the models are depicting a fairly active pattern over the next few weeks, with multiple systems off the Pacific coast (some fairly strong), and some staying fairly strong as they emerge onto the Plains. If we can get sufficient moisture return (the big "if" in February), perhaps we might be entering a favorable pattern for severe thunderstorms soon if the models verify.

And the slight risk is back into the DFW metro as well, and even now extends south of DFW for wind and hail. Highest tornado probabilities (5% within 25 miles) are in the northern section of the metro northwards to the Red River and over towards NE TX, SE OK, and central AR. It's also interesting to see the elevated thunderstorms in NW OK, where there is a severe thunderstorm warning in effect for an area where some of the surface temperatures are hovering near the freezing mark. Now if only that activity was in the warm sector...

This isn't my subforum, but I did find it interesting that the 0z NAM and 0z NAM3K are trying to bring lower 60s dewpoints into southern and central Ohio for Thursday, along with small amounts of SBCAPE. The model is also showing the moist air in southern IL and southern IN as well, though it penetrates further north in OH and at a more ideal time of day (afternoon). Some of the earlier NAM runs had the same or similar dewpoints reaching southern and central Ohio. Plenty of helicity too. That said, I understand that the NAM models can be a bit overdone sometimes.

I know it's still early, but I'm already starting to get a bit concerned for this year's severe weather season with the arctic outbreaks happening over the eastern US, especially if the whole pattern with western ridging and eastern troughing gets established; to my understanding, this pattern ruined the severe season many times in the middle of this decade. With drought expanding in the west there may be more concern for western ridging. That said, if a western ridge can be combined with a ridge over the East Coast and troughing in the central U.S. (as the aforementioned CPC outlook seems to suggest) then maybe we will get several storm systems that move from the southern Plains towards the Great Lakes region. To my (limited) understanding this would be better with La Niña conditions though if you wanted to bet on tornado outbreaks. I'm going to be a bit more optimistic here and guess first high risk on April 11th in the southern Plains, with 1200 tornadoes overall.

Only marginal risk on Friday. Perhaps a little bit of hail (especially in North Texas) but little surface-based instability as per SPC. I wasn't going in expecting anything either.

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.

Interesting note regarding the location of the freezing line. Some of the personal weather stations on Wundermap (accuracy is a concern though) are averaging around 32 in portions of southern Dallas County (and close to it in Irving and NW Dallas County), and even in the areas that based on radar data appear to be just plain rain in SE Tarrant are averaging around 32 as well. Here in west Fort Worth a light coating of ice has formed on my tree branches. It will be interesting to see how far west the freezing line shifts over the next few hours, and part of me wonders if it will not shift as far west as forecasted. Hopefully the freezing line shifts west out of DFW in the next couple of hours as forecasted, before there is an opportunity for ice accumulation to become a major issue.

I'm on the west side of Fort Worth and there is currently a light rain with temperatures just below freezing (31F), with most of Tarrant County (aside from the easternmost portions) also at or just below freezing. Paved surfaces seem wet and not icy at the present moment, although there does seem to be a little bit of ice on surfaces that are less likely to retain warmth (like leaves and the metal railing just outside my house). Concern for icing seems to be further west where precipitation has yet to develop (but will), as per SPC mesoscale discussion.

Should be interesting to watch, that's for sure. And in fact, this morning's 6z NAM run is showing a potential icing event from the Hill Country up towards DFW, with greater ice accumulations showing up around Llano and Gatesville (with the event ongoing at the end of the run, though it's too early to delineate where winter precipitation may accumulate at this time). But like you mentioned, the GFS and other global models are not picking up on anything.

Not severe at the moment but there appears to be strengthening cell on radar near San Saba, TX. There is good overlap between helicity and instability there per the SPC mesoscale analysis page. SPC also just issued a "tornado watch likely" mesoscale discussion for this area as well.

Winds are picking up here in Fort Worth. Also, SPC has expanded the Enhanced risk zone further west and northwards, now including Abilene and reaching just south of DFW. Slight risk now goes up to the Red River and even includes a little bit of southern OK. Definitely seems that the SPC is hinting towards stronger moisture return further north, as the tornado risk has also shifted northwards too.

And we now have an enhanced risk (with 10% tornado risk/30% severe wind risk) including Austin and the NW suburbs of Houston, with the slight risk extending northwards to DFW. I'm a little skeptical of severe in DFW given that most of the models tend to keep them in the lower-to-mid-60s for temperatures (with dew points a few degrees lower) along with what appears to be multiple rounds of convective precipitation, though the shear seems good, and the models have at least trended a little bit upwards on moisture return. The presence of isolated thunderstorms in a high-shear environment on the HRRR and NAM 3k does have me a bit intrigued, though much of this appears to be elevated convection ahead of the main line. With such a slow year for severe thunderstorms it has been at least it is something. Hopefully 2019 will have some more interesting setups to look forward to.

New Tornado Watch issued, including most of the DFW area (Tarrant & Dallas counties northwards). SPC seems to not be ruling out the possibility of storms in DFW.

Though DFW has been dropped to a Marginal risk, a few of the models are bringing DFW back in on storm action, especially the last couple runs of the HRRR.

I wonder what everyone is thinking about the severe weather potential tomorrow in Texas? Currently SPC has a slight risk in place for an area roughly bounded by Fort Worth to the NE, Killeen to the SE, and Abilene to the W. Multiple NAM and NAM3K runs are getting some pretty high EHI values into parts of the north-central Texas region, though SPC is calling the NAM overdone. Just waiting for what the 18z HRRR run has to say, though; that said, the 12z HRRR run does keep the surface-based instability south of the DFW Metroplex by about 2 counties or so.

Storm initiation happening now over the Fort Worth area, with a severe storm SW of Fort Worth. Severe outlook also downgraded to Enhanced risk for NW OK and SW KS.

Tornado warning now for Collin County, including highly populated areas of McKinney and Plano.

Seems a bit weaker on radar now, but there is a severe-warned storm just to the west on its heels. The storm near Celina also seems to be developing a hook with what appears to be some rotation on radar.

That storm only took like 20 minutes to go from a blip on the radar and then go severe... talk about explosive development. The atmosphere is indeed very unstable.

Severe thunderstorm warning now up for northern Denton and Collin counties. Although this warning is mostly north of the built-out parts of the DFW metroplex, to the southwest of the warning, storms trying to form near Springtown and Azle could potentially grow into a hail threat for the Metroplex.

Severe thunderstorm watch now out along the I-35 corridor in Texas from the Red River down to Temple, including the DFW area.