WeatherArc

Big time uptick in severe weather likely going into next week with a day 6 and 7 15% issued with another 15% likely to be issued for Saturday as well. Heres what our GEFS is showing, decent support for an initial shortwave on the 25th followed by a larger trough ejection around the 27th. Past few runs of the GFS have also shown this ejection, good moisture and instability in place The Euro/EPS seems to agree with the GFS, slightly different in how it ejects the trough in regard to timing but thats to be expected at this range. Tilt of trough, and surface features such as the surface low positioning and mass response all still unclear at this range.

Ben Sainsbury I do think we are starting to enter a much more active period for severe weather, late April May and even June should be this years main show. GFS/GEFS looking fairly active as we go into late april/early may

As noted by a few on twitter tomorrow in Texas is looking quite interesting, high-extreme cape but with very low cape. Storms firing on a stationary cold front/dryline intersection, could be a few storms 'zippering' along the boundary and moving to the south west. Heres a comparison between the HRRR and Nam 3k, the Nam usually over moistens the atmosphere while the HRRRs overmixing bias dries things out so expect a middle between these models to verify High dewpoint values should lead to large cape profiles developing. This bigtime cape will lead to explosive updrafts But shear will really be on the low side with bulk shear of only 30 knots and below and 3km inflow of less than 20 knots. Having said that i wouldnt rule out a tornado threat, low level instability and vorticity (especially aided by the boundary) combined with the general large instability profiles could foster a tornado threat with a cell that can latch onto the boundary and slide down it. In fact, looking at this setup im reminded of Jarrell 1997, NO we are not going to get an F5 or anywhere close to that day, but looking at tornado archives the setup does bare some resemblance although cape will be weaker than in Jarrells case. Heres a few soundings, all taken from south Dallas, near Waco. HRRR Nam 3km I think i enjoy these days over high shear low cape, very mesoscale driven. Certain boundaries, pockets of vorticity or even surges in the RFD can lead to interesting things. Certain fail modes relate to storms quickly becoming OFD due to dry air, a more clustered mode or the weak shear overall stunting tornadogenesis/cell development Apart from the tornado threat large hail and wind damage are all possible. As said earlier the tornado risk tomorrow will be completely down to the mesoscale, or even storm scale environment. Regardless, doesn't look like too bad of a day to chase, these Texas high cape storms are always absolutely beautiful.

Some amazing pics from Iowa last night, many extremely photogenic tornadoes Including this low topped beaut of a supercell Even an attempt at triplets! Also some great satellite views of the cyclone that caused this tornado outbreak Always good to see reed dominating those tornadoes, believe this is only his second intercept since he got the dominators back out in 2022. Looking forward a conditional risk for severe weather is in place today and especially tomorrow, hrrr has cells firing on a stalled cold front in a high cape low shear environment, could foster a tornado threat depending on the mesoscale conditions. After that we should get a brief quiet period before the CFS suggests a real ramp up in severe probabilities as we enter late April and early May.

Found this on twitter lmao Eagle Eye Had class first thing so couldn't stay up, never underestimate the ability of the great plains to do a blue sky cap bust Ben Sainsbury Not surprised that storm did nothing looking at that profile that 700mb dry punch is brutal, good job with that forecast earlier verified pretty well believe the storm went just west of dodge city. We have another enhanced risk today with a 10% hatched tornado risk, mostly over Iowa. This ones still a little conditional as well but imo much greater odds of sig tors today over yesterday. Our conditionality lies with how quickly the atmosphere can recover, radar shows a band of clustered severe thunderstorms (some with embedded circulations that i believe have already produced a few weak tors) over our target area, this band should clear to the east and allow for development of discrete supercells by around 21z Now normally, the distance between the first clustered band and the more discrete mode would cause concern due to cloud cover leading to slower recovery of temps and instability however satellite reveals that a large EML punch is apparent due to the cyclones relatively mature development, this upper level dry air should help aid quick recovery and subsequent destabilisation. We should get a 47-55 knot low level jet to develop with largely 250+ 0-3km SRH, adequate for strong tornadoes if cells can remain discrete. Cape doesnt look like a problem, that EML slot should clear clouds and allow for destabilisation with around 2000 j/kg of mlcape Elevated EHI and sig tor values just ahead of cells. Profiles from Southern Iowa Profiles from Northern Missouri Profiles from Central Missouri Abundance of 3cape, should help cell's mesocyclones out

Decided to stay up just to see if the 00z models would show anything. The first thing that becomes apparent is the HRRR is handling this event incredibly poorly, moisture return is much more extensive than previously thought. HRRR vs Actual observed sounding, 8 degrees off. Heres the dewpoint error from earlier today. In fact, it seems the NAM is handling this event much better than it usually does. So looking at the 00z 3k nam we get a storm to fire in central Kansas, close to areas such as Ness city. Taking a sounding from the inflow region of said storm the Nam has a very potent environment. Now compare that to a HRRR sounding from the same area Both these models have there biases and at the moment they are really showing, i do have a bit more confidence on tomorrow actually doing something though. Seems like its going to be a day of watching observed soundings and mesoscale data as well as taking the risk of chasing on the off chance you see a Kansas wedge.

Alderc 2.0 agreed, ill admit i overhyped it but ill blame it on boredom and my thoughts that we couldn't get another event to completely underperform Hrrr does fire storms but the environment has been severely downgraded from what it was, we could still see upgrades but im not particularly hopeful Maybe its due to how active this stretch was last year with the highrisk but pretty much all of the setups so far have been messy with the higher end potential overhyped by models then severely downgraded in the last 24 hours. Im just hoping May can give us a bit more action

When the top 2 analogs for mondays system are April 14th 2012 and May 3rd 1999 i start to get very interested. The amplification of the trough seems to be the biggest question at the moment, we'll see where we are at when the CAMS begin to come into range this weekend. 18z GFS is just a classic look for a tornado event in the southern plains, almost a sub 980mb low Also large wedge tornado earlier today in Florida! Not much in the way of damage reports at the mo but will try to see if any on twitter

wow 12z Euro coming in for Monday with a very high-end likely tornado outbreak for Oklahoma and Kansas, the gfs is now the only outlier with a slower trough ejection and i would expect it to cave to the other models soon. 983 mb low! Some soundings When you compare to other model runs apart from the GFS there's pretty decent agreement. Icon UKMet Still 132 hours, this may well fall apart but with all this agreement in models alarm bells for a significant severe weather episode in the southern plains are sounding. Alderc 2.0 Agreed, 9/10 times outbreaks in the deep south aren't great due to messy storm modes and lapse rates, hopefully we are starting to see a transition to classic tornado alley with its highly visible tornadoes.

A very rare day 6 30% severe has now been issued for portions of Northern Texas, Oklahoma and southern Kansas. Per the SPC "The actual severe weather setup appears substantial. Air mass modification will ensue northward from the western Gulf on D3, with multiple days to improve the low-level moisture profile amid well above-normal surface temperatures and a pronounced elevated mixed layer. With the likely flow field amplification through the troposphere, all ingredients appear present for a significant severe weather day on D6/Monday. The areal uncertainty of the synoptic features is the primary limiting factor. For now, have added a confined 30 percent highlight to indicate the higher-end potential and the most probable corridor, while broadening the previous 15 percent area." Its not often we see such confidence in severe weather this far out, the last day 6 30% in the plains was the May 20th 2019 high risk. Confidence still a little iffy due to differences in timing but both euro, gfs and icon have significant severe weather setups.

Yeah that could be an issue, HRRR now developing a discrete cell ahead of the line for Wednesday.

Our active period continues today and tomorrow with an enhanced and moderate risk. Tonight an elevated tornado threat will develop across eastern Texas, any cell that can develop and track across the warm front has increased likelihood of producing a strong or even violent tornado, significant hail is also possible alongside damaging wind gusts. For tomorrow, the SPC has upgraded the risk to a moderate as a powerful MCS (with potential to develop into a Derecho) will track across the Mississippi, Louisiana, Alabama regions. A rare 45% hatched wind risk for gusts exceeding 75mph as well as a 15% hatched risk for strong QLCS tornadoes that can spinup. Looking even further ahead, the spc has issued a day 7 15% for the system we've been watching since Saturday, a negatively tilted trough will eject into the plains with ample moisture, still some uncertainty on whether the ejection will occur during peak heating or not, could be a significant tornado day if all things line up but can swing either way at this range. AndrewHamm Early may still has that favourable look on the long range models, you know its pretty significant when people start mentioning 2011 and 2013 as analogues!

Reed timmers going up live in a plane