cheese007 Posted April 23 Share Posted April 23 Active few days on the plains starting Thursday. At a glance looks kinda messy for tor potebtial but something to watch SPC AC 230730 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Tue Apr 23 2024 Valid 251200Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTHERN AND CENTRAL GREAT PLAINS... ...SUMMARY... Severe thunderstorms may develop late Thursday afternoon into Thursday night across parts of the central and southern Great Plains. Large hail, severe wind gusts, and a few tornadoes will all be possible. ...Synopsis... A shortwave trough initially over the Southwest is forecast to take on an increasingly negative tilt as it moves eastward towards the central/southern Plains by Thursday night into Friday morning. In response, a surface low will consolidate and deepen across the central High Plains through the day, before moving northeastward toward northwest KS/southwest NE by Friday morning. An initially stationary surface boundary will move northward as a warm front across the central Plains through the day. Along/south of the warm front, relatively rich low-level moisture will stream northward to the east of a dryline that will become established from the eastern TX Panhandle into western KS and eastern CO. ...Southern/central Great Plains... Coverage of the severe-thunderstorm threat remains somewhat uncertain, but a couple intense supercells are possible by Thursday evening near the dryline from western KS into western OK and the TX/OK Panhandles. Another round of overnight convection will potentially bring the severe threat eastward into a larger portion of the central/southern Plains. The warm sector of the deepening cyclone will likely remain capped for much of the day, though elevated convection may persist from parts of central/eastern KS into eastern OK, to the north of the effective warm front. Increasing moisture beneath steep midlevel lapse rates will support MLCAPE in excess of 2000 J/kg along/east of the dryline, as deep-layer shear strengthens across the region through the day. Ascent attendant to the approaching shortwave trough will begin to impinge upon the warm sector by late afternoon, with isolated supercell development possible near the surface low across southwest KS and southward down the dryline into the TX Panhandle. Very large hail (potentially 2-3 inches in diameter) will likely be the primary initial hazard. A notable increase in low-level flow/shear near and after 00Z will also support a tornado threat with any supercells that can persist into the evening across parts of western KS/OK. While any initial dryline storms may weaken by mid/late evening due to increasing MLCINH with eastward extent, renewed storm development is possible overnight along the Pacific cold front from southwest TX into western/central KS/OK as stronger large-scale ascent overspreads the region. Steep midlevel lapse rates, moderate buoyancy, and strong low-level and deep-layer shear will conditionally support a severe threat with overnight convection across the warm sector, though storm mode may become complex and tend toward a linear evolution with time. Severe wind gusts may become an increasing threat with the nocturnal convection, though hail and a couple tornadoes will also be possible if semi-discrete or embedded supercells can be maintained. ...NE/WY border region into northeast CO... Low-level southeasterly flow will support modest moisture return into parts of northeast CO, southeast WY, and western NE, to the north of the deepening cyclone. Thunderstorm development will be possible near and to the cool side of the effective warm front during the afternoon. While deep-layer shear will be weaker compared to areas farther southeast, steep midlevel lapse rates will support an isolated hail threat. A tornado also cannot be ruled out, if surface-based storms can be maintained within this regime. ..Dean.. 04/23/2024 ZCZC SPCSWOD48 ALL ACUS48 KWNS 230859 SPC AC 230859 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Tue Apr 23 2024 Valid 261200Z - 011200Z ...DISCUSSION... A complex but active pattern is expected from D4/Friday through D6/Sunday, as multiple mid/upper-level shortwave troughs impinge upon a moist and unstable environment extending from the southern/central Great Plains into parts of the Midwest and Mississippi Valley. ...D4/Friday - Central/southern Plains into the mid MS Valley... A negatively tilted shortwave trough is forecast to move northeastward from the Great Plains toward the mid/upper MS Valley on Friday. Most guidance suggests that convection developing late in the D3/Thursday period will be ongoing Friday morning, potentially posing an organized severe threat as it moves eastward. The influence of early convection on warm sector evolution by Friday afternoon/evening remains uncertain, but in general, moderate destabilization will be possible along the Pacific front/dryline in the wake of early convection, with some intensification of early storms also possible farther east. Details regarding storm mode remain uncertain at this forecast range, but in general, severe storms capable of producing large hail, damaging winds, and a few tornadoes will be possible across a broad region from the eastern Great Plains into the mid MS Valley. ...D5/Saturday - Central/southern Plains into the Midwest/mid MS Valley... The negatively tilted shortwave trough and attendant occluding surface cyclone are forecast to gradually weaken as they move across the upper Great Lakes region on Saturday. Depending on timing of the departing cyclone and magnitude of diurnal destabilization, some severe-thunderstorm threat could evolve in advance of this system through the afternoon across parts of WI/IL into MI, but confidence remains too low to include 15% probabilities for this area. Meanwhile, another strong shortwave trough is forecast to eject across parts of the central/southern Plains Saturday afternoon and evening, accompanied by strong surface cyclogenesis across the central High Plains. Moderate to locally strong instability may redevelop along/east of the dryline across central/western KS/OK into north TX, as low-level and deep-layer shear strengthen through the day. The synoptic pattern depicted by much of the extended-range guidance is suggestive of an active severe thunderstorm episode along/ahead of the dryline, though some guidance (notably recent runs of the ECMWF) suggest potential for early development across parts of OK/north TX, which could complicate the scenario by late afternoon/evening. Some severe threat could spread toward parts of the mid MS Valley late in the period. ...D6/Sunday - ArkLaTex into parts of the Midwest... Predictability begins to decrease by late in the weekend, though in general, a mid/upper-level trough and attendant surface low are forecast to move from the central Plains toward the upper Great Lakes region. A corridor of severe thunderstorm potential is forecast to extend south-southwestward from the surface low, as a trailing cold front moves through a moist, unstable, and favorably sheared environment. A 15% area has been added where confidence is currently greatest in severe-thunderstorm potential Sunday afternoon and evening. ..Dean.. 04/23/2024 Link to comment Share on other sites More sharing options...
Amped Posted April 23 Share Posted April 23 My bar is 1 EF1 over the course of 3 days. It's that kind of year. 1 1 Link to comment Share on other sites More sharing options...
mnchaserguy Posted April 23 Share Posted April 23 I’ll be coming from Minneapolis on Friday so my plan is to chase the warm front Friday afternoon in Iowa. Now that it’s finally in range on the nam, central/southern IA looks to be where the warm front will set up Friday afternoon. Taken verbatim, the 12 nam shows an MCS developing across central Iowa with a tail end Charlie moving through a pretty good parameter space. That being said, this is only one solution several days out so it’s hard to know exactly what to expect right now. At this point, all I can plan on is leaving Minneapolis by 11:00 am and driving south to try to be in position for the afternoon. Friday could be impacted by convection from the night before, but right now Thursday looks to remain mostly capped. Even with parameters and moisture really ramping up after dark on Thursday night, most models look like they remain dry. I would think this would be a good thing for Friday so we don’t risk mid day convection ruining the atmosphere. Saturday looks like a pretty solid day in the central plains. Dryline with deeper moisture in the warm sector with a strong jet streak overhead should lead to a good set up. Problem I see is some of the best parameters stay way south in southern OK, likely due to some early convection firing farther north. My current plan is to try to make it to KC on Friday night and head south to chase the dryline Saturday afternoon, possibly as far south as southwest OK if I have to.Was hoping to chase Sunday but it looks like the system might be too far east for my liking by Sunday. Could be some potential right up next to the center of the low, similar to what happened in northwest IA last week. That would probably be a really conditional threat if anything. . 1 Link to comment Share on other sites More sharing options...
Quincy Posted April 23 Share Posted April 23 The synoptic pattern has multiday potential, but I’ve learned to be skeptical until the day of. All of the hype lately (mainly talking about social media and news outlets, not here) is way overblown. Last week was supposed to be some historic event and it was mostly a dud. Every forecast trough is supposedly the “best setup in years” according to some. It’s really muddying the waters and desensitizing the general public. Big trough in spring ≠ mega outbreak. Despite living in Oklahoma, I’ll most likely be sitting these events out. With the hype and potential location, it will be a zoo storm chasing anyway. Being the rebel that I can sometimes be, I’ll be out in West Texas today and tomorrow. There’s a low probability for an isolated supercell both days. Sure, nothing might happen, but I’d prefer to be out when it’s quiet, rather than a circus. 6 1 Link to comment Share on other sites More sharing options...
andyhb Posted April 23 Share Posted April 23 20 minutes ago, Quincy said: The synoptic pattern has multiday potential, but I’ve learned to be skeptical until the day of. All of the hype lately (mainly talking about social media and news outlets, not here) is way overblown. Last week was supposed to be some historic event and it was mostly a dud. Every forecast trough is supposedly the “best setup in years” according to some. It’s really muddying the waters and desensitizing the general public. Big trough in spring ≠ mega outbreak. Despite living in Oklahoma, I’ll most likely be sitting these events out. With the hype and potential location, it will be a zoo storm chasing anyway. Being the rebel that I can sometimes be, I’ll be out in West Texas today and tomorrow. There’s a low probability for an isolated supercell both days. Sure, nothing might happen, but I’d prefer to be out when it’s quiet, rather than a circus. I'm going to tell you right now that that's probably a mistake on Thursday. 2 Link to comment Share on other sites More sharing options...
cheese007 Posted April 24 Author Share Posted April 24 Thursday bumped up to ENH SPC AC 231831 Day 3 Convective Outlook AMEND 1 NWS Storm Prediction Center Norman OK 0131 PM CDT Tue Apr 23 2024 Valid 251200Z - 261200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE EASTERN TX PANHANDLE AND WESTERN OK INTO SOUTHWEST/SOUTH-CENTRAL KS... AMENDED TO UPDATE FORECAST ...SUMMARY... Severe thunderstorms are likely from late Thursday afternoon into Thursday night across parts of the central and southern Great Plains. Very large hail, severe wind gusts, and strong tornadoes will all be possible. Guidance continues to suggest strong buoyancy will be in place ahead of a negatively tilted shortwave trough ejecting across the southern High Plains. General forecast expressed in the previous outlook remains valid, but confidence in an area of greater severe-weather potential has become more apparent with the most recent guidance. Late afternoon development is anticipated across the TX Panhandle, with these storms quickly becoming severe and capable of large to very large hail up to 3" in diameter. Low-level moisture may be later to arrive in west-central/southwest KS, delaying convective initiation to a few hours later than farther south. Large to very large hail is anticipated with initial development across west-central/southwest KS as well. In both of these areas, storms are expected to move east-northeastward off the dryline, encountering strengthening low-level southerly flow and environment that is increasingly favorable for tornadoes. Low-level shear will continue to strengthening into the early evening, and the overall environment supports the potential for strong to intense tornadoes if a discrete mode can be maintained. Link to comment Share on other sites More sharing options...
Tezeta Posted April 24 Share Posted April 24 Something bad is going to happen 2 Link to comment Share on other sites More sharing options...
mnchaserguy Posted April 24 Share Posted April 24 Saturday is finally within range of the NAM and it is throwing out some big parameters across KS/OK. The dry line and warm front both look like good options. As long as things don’t go early, it could be a pretty big day. My biggest concern is storm motion. Forecast soundings showing bunkers right storm speeds at 40+ knots. That’ll make chasing difficult if those are accurate. . Link to comment Share on other sites More sharing options...
Quincy Posted April 24 Share Posted April 24 Two part post, first focusing on recent and short-term severe threats, then addressing Thursday and beyond. Yesterday I headed out to West Texas for a conditional supercell threat. Storms initiated near a triple point in the afternoon and one transient supercell evolved. I tracked the storm across Fisher and Nolan Counties, before calling it a day when the storm passed over I-20. Structure was as expected, noteworthy and interesting, but nothing super crazy or "epic." If anything, the scene from the backside of the storm with mammatus and nearing sunset was the most photogenic. Today I'm focusing on West Texas again, albeit slightly farther west than yesterday. Moisture and instability should be more favorable today, although forcing is a bit more nebulous. 500mb height tendencies should be fairly neutral, although there are hints of a weak disturbance ejecting off the Southern Rockies later today. Convergence will be maximized near the dryline and there is the potential for isolated convection around 00z. For several runs, the HRRR was very consistent showing convective initiation, although recent runs have backed off a bit. Other high resolution guidance is mixed, but seems to argue against a storm being able to form. The 12z 3km NAM shows attempted, but ultimately failed CI. The SREF is more mixed, but several members do show convection in West Texas between 00-03z. I'd say the odds are close to 50/50 at sustained convection forming. Given the setup, any convection should be very isolated. If a storm does form, with better low-level moisture and a larger warm sector than yesterday, it will likely become severe. Now that I've had an opportunity to actually look at Thursday in some detail, here's what I think: Thursday Synoptic pattern certainly suggests a threat of significant severe. Some of the surface features still need to be resolved, but the expectation is for lee cyclogenesis off the Front Range late Thursday. At least isolated convective initiation seems likely from eastern Colorado into western Kansas and possibly parts of southwestern Nebraska/panhandle. The increasing low-level jet and strongly backing flow in the boundary layer suggests significant severe will be possible, including a strong tornado potential. If there's any caveat for the Central Plains portion of the threat area, it's that early day convection on Thursday could play a role on the quality and size of the warm sector. Some guidance shows widespread morning precipitation over Kansas, which could narrow the warm sector, especially if outflow surges far enough south. Still, even the worst case scenarios manage to form isolated storms in western Kansas late Thursday. Further south into the Oklahoma/Texas panhandles and far western Oklahoma... convective initiation is much more uncertain. While many of the global models show convection, high resolution models either show weak/failed or no attempts at sustained convection. The background environment would conditionally favor convective initiation, given substantial height falls, large buoyancy and favorable low-level moisture (much better than last week). With that said, I pulled some forecast soundings and it appears that residual capping tries to preclude storms. The new 12z 3km NAM has taken a step toward more storm potential, showing a narrow sliver of eroded convective inhibition just ahead of the dryline. This is reflected with attempts at CI in the reflectivity fields. One last observation for Thursday is that the analog guidance is surprisingly wimpy looking. A few analogs do point toward enhanced (for the lack of a better word) events, but several show little to no severe storms. Obviously, that extreme seems unlikely, but the most probable solution is that severe storms are isolated to scattered, rather than widespread up and down the entire length of the dryline. Most of the analogs narrow in on northeastern Colorado into Kansas, which makes sense given the setup. Again, activity farther south is more uncertain, but if a sustained storm is realized down there, significant severe would also be possible. Friday A surface low deepens and occludes across Nebraska during the day with a pronounced shortwave impulse. Model guidance shows a robust daytime low-level jet ejecting east, in excess of 50 knots across Missouri, but also becoming increasingly displaced from better buoyancy to the west. Convective initiation seems likely from eastern Nebraska, southeast across the Lower Missouri Valley. Storms farther south toward the Ozarks and eastern Oklahoma is a bit more uncertain. Either way, even if storms do form, they'll be pushing into an increasingly hostile environment for storm chasing. Saturday I try not to get caught up in details this far out, so I'm not going to analyze this potential threat too much. There is also great uncertainty and wide model spread with convective evolution through the day. On the heels of Friday's shortwave, a deeper shortwave is forecast to dig across Colorado/New Mexico, ejecting across the Plains. The most glaring red flag that I see at this juncture is for the potential for widespread early day precipitation/convection. That could really throw a wrench in this threat, as if there is more capping and limited daytime precipitation, the setup otherwise looks like it could have a high ceiling across much of Kansas/Oklahoma/Texas. We'll have to stay tuned and see how things evolve. 2 3 Link to comment Share on other sites More sharing options...
mnchaserguy Posted April 24 Share Posted April 24 This is about as nice of a forecast sounding as you can get. What can go wrong. . Link to comment Share on other sites More sharing options...
Quincy Posted April 24 Share Posted April 24 3 minutes ago, mnchaserguy said: This is about as nice of a forecast sounding as you can get. What can go wrong. . It’s the 84hr NAM. That’s all we need to know. Plus that sounding is a bit contaminated. So much can change this far out, especially with earlier season events. The potential spread for Saturday is quite large. We first need to see how the next couple of days evolve, then focus shifts toward the potential for early initiation on Saturday. 1 Link to comment Share on other sites More sharing options...
nrgjeff Posted April 24 Share Posted April 24 I have no dog in the hunt, because my back-up is already on vacation not related to weather. I'm not chasing, but this should be a quality sequence. Thursday the morning rain eastern KS will kick out an OFB that should stay separate (south of) the WF. It's my preferred chasing scenario OFB DL intersection. No concerns upper levels. Thursday looks lit! Friday is farther east. I'd chase outside of the KC metro because I know the area. It is not jungle outside the city. Could be a wide area though. Depends on Thursday night. Saturday the true Plains relaods. Upper levels have a kink or two. However moisture will be deeper than on Thursday. Boundaries will be around. Saturday could be a day. Sunday is kind of Friday echo, but that far out we really don't know much after 3 days of convection. At any rate this looks like a true Plains sequence. Y'all at some point you need to decide to travel to the Plains. Waiting for the perfect set-up = never going. 1 Link to comment Share on other sites More sharing options...
mnchaserguy Posted April 24 Share Posted April 24 It’s the 84hr NAM. That’s all we need to know. Plus that sounding is a bit contaminated. So much can change this far out, especially with earlier season events. The potential spread for Saturday is quite large. We first need to see how the next couple of days evolve, then focus shifts toward the potential for early initiation on Saturday. I think most chasers (myself included) understand that things need to be taken with a grain of salt at this point. . Link to comment Share on other sites More sharing options...
Tezeta Posted April 24 Share Posted April 24 I’m going to go post up in sterling tomorrow and try to catch a landspout. Will leave the main outbreak sequence to the Kadens and Jadens and halls of the world. Link to comment Share on other sites More sharing options...
Floydbuster Posted April 24 Share Posted April 24 Legit question: For several weeks, actually over two months now, my social media feeds have been filled with images of model runs and warnings of severe weather. Soundings and HRRR runs and NAM runs for the upcoming week, etc. etc. Yet week after week passes without any images of tornadoes or tennis ball sized hail or anything half as significant as what I see warned about on social media the week prior. This goes for the Ohio valley, the Great Plains, pretty much anywhere. So my question is...are the models overestimating storms this year? Or am I just on social media filled with salivating amateur storm chasers desperate to get a glimpse of a funnel cloud? Link to comment Share on other sites More sharing options...
cstrunk Posted April 24 Share Posted April 24 7 minutes ago, Floydbuster said: Legit question: For several weeks, actually over two months now, my social media feeds have been filled with images of model runs and warnings of severe weather. Soundings and HRRR runs and NAM runs for the upcoming week, etc. etc. Yet week after week passes without any images of tornadoes or tennis ball sized hail or anything half as significant as what I see warned about on social media the week prior. This goes for the Ohio valley, the Great Plains, pretty much anywhere. So my question is...are the models overestimating storms this year? Or am I just on social media filled with salivating amateur storm chasers desperate to get a glimpse of a funnel cloud? It seems to me like the SPC is highlighting risk areas in Days 4-8 more than in the past. That used to be more of a big deal, as it seems like they would only do that for days with a much higher certainty of some kind of severe weather outbreak, and those would end up being more like true "Moderate" risk type days (which are much more infrequent). Now they are highlighting those areas and they don't end up being huge outbreaks, just standard "Slight" or "Enhanced" risk type days. But not significant, like you mention. I think social media is making it worse. There's so many variables and failure modes, that confidence can't be that high at those ranges to start highlighting "Super Outbreaks" headlines that we've seen from some. 6 Link to comment Share on other sites More sharing options...
Powerball Posted April 24 Share Posted April 24 10 hours ago, cstrunk said: It seems to me like the SPC is highlighting risk areas in Days 4-8 more than in the past. That used to be more of a big deal, as it seems like they would only do that for days with a much higher certainty of some kind of severe weather outbreak, and those would end up being more like true "Moderate" risk type days (which are much more infrequent). Now they are highlighting those areas and they don't end up being huge outbreaks, just standard "Slight" or "Enhanced" risk type days. But not significant, like you mention. I think social media is making it worse. There's so many variables and failure modes, that confidence can't be that high at those ranges to start highlighting "Super Outbreaks" headlines that we've seen from some. I suspect the fleeting El Nino is also having an effect. The seemingly persistent high/mid-level cloud cover advecting in from the Pacific with the unrelenting subtropical jet puts a cap on the diurnal temp swings, thus the extent of instability, in these setups. Link to comment Share on other sites More sharing options...
Floydbuster Posted April 24 Share Posted April 24 53 minutes ago, cstrunk said: It seems to me like the SPC is highlighting risk areas in Days 4-8 more than in the past. That used to be more of a big deal, as it seems like they would only do that for days with a much higher certainty of some kind of severe weather outbreak, and those would end up being more like true "Moderate" risk type days (which are much more infrequent). Now they are highlighting those areas and they don't end up being huge outbreaks, just standard "Slight" or "Enhanced" risk type days. But not significant, like you mention. I think social media is making it worse. There's so many variables and failure modes, that confidence can't be that high at those ranges to start highlighting "Super Outbreaks" headlines that we've seen from some. Good point. I do see a trend of Thursday-Friday twitter hype for the upcoming Monday-Tuesday work week, and it just dawned on me this seems to keep repeating without any *actual* large events. 1 Link to comment Share on other sites More sharing options...
Tezeta Posted April 24 Share Posted April 24 2 hours ago, Floydbuster said: Legit question: For several weeks, actually over two months now, my social media feeds have been filled with images of model runs and warnings of severe weather. Soundings and HRRR runs and NAM runs for the upcoming week, etc. etc. Yet week after week passes without any images of tornadoes or tennis ball sized hail or anything half as significant as what I see warned about on social media the week prior. This goes for the Ohio valley, the Great Plains, pretty much anywhere. So my question is...are the models overestimating storms this year? Or am I just on social media filled with salivating amateur storm chasers desperate to get a glimpse of a funnel cloud? weird that you're perceiving a crappy tornado year because ohio has been red hot Link to comment Share on other sites More sharing options...
andyhb Posted April 24 Share Posted April 24 1 hour ago, Floydbuster said: Good point. I do see a trend of Thursday-Friday twitter hype for the upcoming Monday-Tuesday work week, and it just dawned on me this seems to keep repeating without any *actual* large events. You're also applying recency bias to this whole discussion and assuming that's going to carry over for 4/25-28. IMO the character (and also background climatology) of this sequence is different, substantially so, than other events that have "underperformed" earlier this year. Already, the moisture quality for tomorrow looks much better than 4/15 in a similar area. The other big factor that could really set Saturday off is the lack of influence from the sub-tropical jet, which is shunted southward by the passage of the first shortwave on Thursday/Friday. That likely removes a number of caveats that have affected other events this year detrimentally. 2 Link to comment Share on other sites More sharing options...
Floydbuster Posted April 24 Share Posted April 24 20 minutes ago, Tezeta said: weird that you're perceiving a crappy tornado year because ohio has been red hot The tornadoes that Ohio has seen this year don't even begin to compare with the hype I've seen for severe events the last few months. The way social media acts is insane. 1 Link to comment Share on other sites More sharing options...
Tezeta Posted April 24 Share Posted April 24 2 minutes ago, Floydbuster said: The tornadoes that Ohio has seen this year don't even begin to compare with the hype I've seen for severe events the last few months. The way social media acts is insane. Theres a demand for the hype. Evan fryberger sits there 3x a week with thousands of viewers and doesn’t even know what a debris ball is. Link to comment Share on other sites More sharing options...
andyhb Posted April 25 Share Posted April 25 1 hour ago, Floydbuster said: The tornadoes that Ohio has seen this year don't even begin to compare with the hype I've seen for severe events the last few months. The way social media acts is insane. Ohio has literally been the most active state for tornadoes this year. Please read more and post less, you're clogging the thread. 1 2 Link to comment Share on other sites More sharing options...
CheeselandSkies Posted April 25 Share Posted April 25 5 hours ago, Floydbuster said: Legit question: For several weeks, actually over two months now, my social media feeds have been filled with images of model runs and warnings of severe weather. Soundings and HRRR runs and NAM runs for the upcoming week, etc. etc. Yet week after week passes without any images of tornadoes or tennis ball sized hail or anything half as significant as what I see warned about on social media the week prior. This goes for the Ohio valley, the Great Plains, pretty much anywhere. So my question is...are the models overestimating storms this year? Or am I just on social media filled with salivating amateur storm chasers desperate to get a glimpse of a funnel cloud? I think a little of both. However, to my point below; each potential threat recently has had some obvious limiting factors apparent in the model data within a few days out (moisture depth, wave timing, etc). 4 hours ago, Powerball said: I suspect the fledgling El Nino is also having an effect. The seemingly persistent high/mid-level cloud cover advecting in from the Pacific with the unrelenting subtropical jet puts a cap on the diurnal temp swings, thus the extent of instability, in these setups. I was under the impression that we were actually currently moving out of El Nino toward neutral and then La Nina (hence also the universally very high-end forecasts for the Atlantic hurricane season)? *** The models showing a big, amplified trough with moisture is one thing; however, details matter. Most of the prior setups this year have had significant caveats become apparent within the 3-5 day range. However the amateur social media hypelords either didn't know or didn't care to point them out. @andyhb is right, this one is not downtrending to any degree that I'm seeing. If anything; each subsequent model run is only reinforcing the idea that the ceiling is quite high and something significant could happen each day starting tomorrow through Sunday. Now, will it? Not necessarily, but confidence it's higher than it's been in quite some time IMO. Link to comment Share on other sites More sharing options...
Powerball Posted April 25 Share Posted April 25 6 hours ago, CheeselandSkies said: I was under the impression that we were actually currently moving out of El Nino toward neutral and then La Nina (hence also the universally very high-end forecasts for the Atlantic hurricane season)? Fleeting was probably a better word. In addition to the increased cloud cover limiting insolation needed for sufficient surface-based instability, there's also some correlation during an El Nino with the weaker surface wind fields limiting the extent to which warm/moist air from the Gulf advects northward (unlike during a La Nina). I wouldn't expect models, especially those that aren't convection-allowing, to pick up on these details several days out. The ENSO state is only one of many factors, but possibly one that shouldn't be ignored/dismissed as a significant factor for the underwhelming season thus far. https://www.climate.gov/news-features/featured-images/el-niño-and-la-niña-affect-spring-tornadoes-and-hailstorms Link to comment Share on other sites More sharing options...
RocketWX Posted April 25 Share Posted April 25 A couple things that have stood out to me for a few days with Saturday that separates it a bit from previous systems, is the trough ejection timing and moisture quality/depth. Today's system is really priming the pump for Saturday. More than anything though is the trough ejection timing. You have a jet streak nosing in, intersecting a dryline during peak diurnal heating, rather than late at night or early morning. The big fly in the ointment as it stands now for me is early convection moving up from the south, wiping out the warm sector. Having said that, I do feel this day has the highest ceiling I've seen in some time for OK/KS, based simply on trough timing and moisture quality alone. Seeing as this is on a Saturday and in prime location, whew boy, chaser convergence is sure to be crazy! 2 Link to comment Share on other sites More sharing options...
Quincy Posted April 26 Share Posted April 26 Seems quiet in here. I take it not much happened today? I saw a few landspout and brief tornado reports, but storms were mainly hail producers. Could see early morning storms (Friday AM) pass from NW Texas into southern Oklahoma, but the tornado threat seems very low. Could see some heavy rain, gusty winds and hail, though. 1 Link to comment Share on other sites More sharing options...
Powerball Posted April 26 Share Posted April 26 1 hour ago, Quincy said: Seems quiet in here. I take it not much happened today? I saw a few landspout and brief tornado reports, but storms were mainly hail producers. Could see early morning storms (Friday AM) pass from NW Texas into southern Oklahoma, but the tornado threat seems very low. Could see some heavy rain, gusty winds and hail, though. There has been a shit ton of large hail reports (not surprising given the ample elevated instability and deep layer shear), but per usual with the setups this season, the extensive mid/upper-level cloud cover steadily streaming in from.the Pacific (thanks to the STJ) limited the extent of surface-based instability/cap erosion. Things could still rip further south in OK/TX along the dryline as the shortwave shifts eastward and the LLJ ramps up, but it will primarily continue to be a vivd lightning, flash flooding and large hail threat. Perhaps things will be different in the Fall or next Spring as we transition into a La Nina ENSO state (and the STJ loses its grip). Link to comment Share on other sites More sharing options...
Powerball Posted April 26 Share Posted April 26 For DFW, as daytime heating gets under way, there *MAY* be a very brief window during the late morning / early afternoon hours today where some tail-end charlies could backbuild and become surface-based with the enhanced low-level covergence, but it will be threading the needle with the better upper-level forcing/dynamics/shear quickly shifting NE. 1 1 Link to comment Share on other sites More sharing options...
Powerball Posted April 26 Share Posted April 26 Link to comment Share on other sites More sharing options...
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