yoda Posted May 6 Share Posted May 6 ay 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 AM CDT Mon May 06 2024 Valid 061300Z - 071200Z ...THERE IS A HIGH RISK OF SEVERE THUNDERSTORMS OVER PARTS OF WESTERN...CENTRAL AND NORTHERN OKLAHOMA TO SOUTH-CENTRAL KANSAS... ...SUMMARY... A regional outbreak of severe weather with multiple strong, long-tracked tornadoes, as well as very large hail and severe thunderstorm gusts, is expected over parts of the south-central Plains from this afternoon through evening. ...Synopsis... In mid/upper levels, a strong synoptic-scale trough was evident in moisture-channel imagery from the northern Rockies, through a low over northeastern UT, then southward to the international border near the AZ/NM line. The main 500-mb low should pivot northeastward toward the Black Hills and deepen by 00Z, with trough northwestward over central MT and southward across eastern parts of CO/NM. A basal shortwave trough -- now from central CO to the Four Corners area -- should swing northeastward then northward, reaching southern SD, western NE and eastern CO by 00Z. This perturbation then should shift northeastward, possibly merging with convectively generated vorticity over NE and SD this evening and tonight, and reaching eastern SD, southwestern MN and IA by 12Z. A weaker, but still influential perturbation -- now over parts of southern NV/northern AZ -- should make a net eastward shift to parts of northeastern NM and the TX Panhandle by 00Z, reaching southern KS and northern OK by 12Z. Associated substantial height falls and DCVA should remain over and north of the Red River Valley through this evening. At the surface, an elongated area of low pressure was analyzed on the 11Z chart over eastern WY, with Pacific cold front across eastern CO and northeastern/north-central NM. A dryline extended from the front over southeastern CO to eastern NM and the TX Trans-Pecos region, and should mix eastward to southwestern KS, eastern OK/TX Panhandles, and west-central/southwest TX by late afternoon. The cold front should overtake the dryline across the central Plains through the afternoon, then over OK overnight. A developing/synoptic warm-frontal zone was apparent from southeastern WY across central KS to southern MO, and should move northeastward to the lower/mid Missouri Valley through the period. The southern warm front -- demarcating the northern rim of a richly moist Gulf airmass from outflow-modified air, was drawn near the Red River from the Arklatex to the southeastern TX Panhandle. This boundary will shift northward through OK and much of KS today while becoming diffuse, and possibly catching up to the northern warm front. ...OK, Southern KS, Red River region... Thunderstorms are expected to develop by mid/late afternoon along and ahead of the dryline, near the eastern TX Panhandle/western OK line or 100W longitude into southern KS, then strengthen quickly to severe levels as they move eastward. Given the already very favorable parameter space by late afternoon, and increasingly so into early/mid evening, the concern is high for at least a few cyclic, tornadic supercells producing multiple significant tornadoes along potentially long paths. The threat for such tornadoes, as well as very large/destructive hail, will be maintained well into the late evening, and may even increase as hodographs further enlarge beneath the LLJ. Some uncertainty lingers as to how many such supercells will track across the outlook area, but given the unusually favorable environment and increasing confidence, a "high risk" outlook is warranted for areas between roughly the I-40 corridor in OK and the US-54/500 corridor in southern KS. Compared to farther north in KS, the environment will feature slightly stronger CINH, very rich low-level moisture (dewpoints commonly upper 60s to low 70s F), lack of frontal forcing (mainly dryline instead), and more orthogonal mean-wind/deep-shear vectors relative to the boundary. The 12Z FWD sounding sampled the richly moist and deep boundary layer that will be shifting northward across OK today, with mean mixing ratio of 15 g/kg. As low clouds erode in the moist sector from west-east, diabatic heating will boost MLCAPE into the 2500-4000 J/kg range over western/central OK and southern/ central KS, and contribute to greater potential for discrete supercells to develop and last a few hours before potential major upscale evolution to lines or clusters this evening. Hodographs will be favorable for tornadoes soon after initiation, and enlarge further ahead of the activity with time. Effective SRH commonly around 200-300 J/kg is expected late this afternoon and 300-500 J/kg after 00Z, amidst strengthening LLJ and deep shear (effective-shear magnitudes reaching 45-60 kt). Effective-layer STP in the 5-12 range may be realized for a few hours this evening across parts of OK and southern KS. Stronger MLCINH and weaker large-scale support will contribute to lesser storm coverage with southward extent over southern OK, though significant tornadoes and damaging hail may be possible from any that form. The corridor of favorable buoyancy will enlarge eastward this evening with continued moisture transport/advection, helping to maintain surface-based effective-inflow parcels well eastward into the Ozarks and vicinity to maintain eventual upscale growth, possibly linking with the southern part of QLCS activity sweeping across the Missouri Valley region. ...Central Plains... Thunderstorms should develop as early as midday to early afternoon over portions of western KS and southwestern NE, where CINH will be weakest, as the southern part of the front overtakes the dryline and impinges on a rapidly destabilizing/moistening sector to the east. Initial supercell mode is possible, with tornadoes (some strong), large to very large hail and damaging gusts all possible. With time this afternoon into evening, a more quasi-linear storm mode may evolve as the influence of frontal forcing increases, versus some component of flow across the boundary. As that occurs, tornadoes still will be possible, and the hail threat will transition to severe wind with eastward extent. Some significant (near 75 mph or higher) gusts will be possible as the momentum of stronger flow aloft gets transported to the surface, with increasing forced ascent along the leading edge of the complex. 60s F surface dewpoints will overspread a northward-narrowing sector across much of KS and NE today, contributing to peak/preconvective MLCAPE increasing into the 2000-3000 J/kg range, as deep shear strengthens, and hodographs extend, while maintaining favorable curvature. Link to comment Share on other sites More sharing options...
Quincy Posted May 6 Share Posted May 6 12z soundings… FWD highlights the boundary layer moisture that will advect north/northwestward: AMA gives an idea of the deep layer wind profile and EML advecting eastward through the day: 3 Link to comment Share on other sites More sharing options...
Torchageddon Posted May 6 Share Posted May 6 The last time OK had a high risk was of course May 20, 2019. I remember this product I think it was from SPC called "Violent Tornado Index" (VTI) or another derivative - I can't find anything like that now. SPC experimental products page has nothing currently. Its not this: https://www.spc.noaa.gov/exper/outbreaks/ Link to comment Share on other sites More sharing options...
southmdwatcher Posted May 6 Share Posted May 6 Are you referring to the VTP(Violent Tornado Parameter)? That is listed under composite indices now. It started out on the beta column. 1 Link to comment Share on other sites More sharing options...
olafminesaw Posted May 6 Share Posted May 6 1 Link to comment Share on other sites More sharing options...
Torchageddon Posted May 6 Share Posted May 6 44 minutes ago, southmdwatcher said: Are you referring to the VTP(Violent Tornado Parameter)? That is listed under composite indices now. It started out on the beta column. That's it, I thought parameter originally. Didn't look into it closely til now, it doesn't have forecast values with RAP. Link to comment Share on other sites More sharing options...
Powerball Posted May 6 Share Posted May 6 Just as a preemptive reminder... 5 Link to comment Share on other sites More sharing options...
Normandy Posted May 6 Share Posted May 6 I’m hoping for early initiation and results. Nighttime events suck for everyone (people watching, people going through it, people chasing, etc). Stay safe everyone! 1 Link to comment Share on other sites More sharing options...
nwohweather Posted May 6 Share Posted May 6 Impressed at the strength of the jet max on the latest models. I don't blame the SPC going with a High risk here, any discrete cells should be able to cover a lot of ground today and put down some prolific tornadoes. With the LCL's projected to be where they are, I wouldn't be shocked to see some nice videos of wedge twisters today. Can't sleep on the damaging wind risk as well, that's going to be a very potent line once everything congeals Link to comment Share on other sites More sharing options...
Tezeta Posted May 6 Share Posted May 6 something bad is about to happen 1 2 Link to comment Share on other sites More sharing options...
olafminesaw Posted May 6 Share Posted May 6 High risk expanded south slightly and wind driven moderate risk expanded east Link to comment Share on other sites More sharing options...
Upper Level LOL Posted May 6 Share Posted May 6 No surprise, but PDS watch incoming later this afternoon https://x.com/NWSSPC/status/1787524998804164785 Link to comment Share on other sites More sharing options...
olafminesaw Posted May 6 Share Posted May 6 What's this feature showing up on long range radar? The dry line? Link to comment Share on other sites More sharing options...
Powerball Posted May 6 Share Posted May 6 12 minutes ago, Upper Level LOL said: No surprise, but PDS watch incoming later this afternoon https://x.com/NWSSPC/status/1787524998804164785 Not surprised. Looking at the SPC mesoanalysis as well as the latest HRRR depicted sounding, the cap is already all but gone in FWD (with dews pooling into the low 70s). At this point, it's just the lack of a meaningful trigger mechanism that's holding development back (for now) with the main shortwave still way back in CO. 1 Link to comment Share on other sites More sharing options...
nwohweather Posted May 6 Share Posted May 6 43 minutes ago, Powerball said: Not surprised. Looking at the SPC mesoanalysis as well as the latest HRRR depicted sounding, the cap is already all but gone in FWD (with dews pooling into the low 70s). At this point, it's just the lack of a meaningful trigger mechanism that's holding development back (for now) with the main shortwave still way back in CO. Still some CIN in the mid levels. What an impressive clash of air masses, you have a dryline featuring dews in the 20's running into a near tropical airmass with dews into the 70's. The LCL's are absolutely ground scraping, especially into East OK/KS at the moment. This evening certainly has a chance to be historic 3 Link to comment Share on other sites More sharing options...
Eskimo Joe Posted May 6 Share Posted May 6 1 hour ago, Upper Level LOL said: No surprise, but PDS watch incoming later this afternoon https://x.com/NWSSPC/status/1787524998804164785 All watches in a high risk area are PDS. 1 Link to comment Share on other sites More sharing options...
MidwestChaser Posted May 6 Share Posted May 6 9 minutes ago, Akeem the African Dream said: only two SVR warnings high risk is busting 1 1 Link to comment Share on other sites More sharing options...
pbrussell Posted May 6 Share Posted May 6 11 minutes ago, Akeem the African Dream said: only two SVR warnings high risk is busting 2 2 Link to comment Share on other sites More sharing options...
Powerball Posted May 6 Share Posted May 6 Agitated CU field has formed along the border of West OK and the TX Panhandle border. I would expect initiation in this area over the next 1-2 hours. Link to comment Share on other sites More sharing options...
Powerball Posted May 6 Share Posted May 6 Link to comment Share on other sites More sharing options...
canderson Posted May 6 Share Posted May 6 34 minutes ago, Akeem the African Dream said: only two SVR warnings high risk is busting 2 1 Link to comment Share on other sites More sharing options...
Big Jims Videos Posted May 6 Share Posted May 6 Following this today from back east. I have close family who just moved to outside of Topeka from the Jersey Shore and they're kinda freaked out by the local hype. Hopefully they're just north of the major impact threats there. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted May 6 Share Posted May 6 1 hour ago, Akeem the African Dream said: only two SVR warnings high risk is busting You laugh but wxtwitter is already calling bust 1 Link to comment Share on other sites More sharing options...
Akeem the African Dream Posted May 6 Share Posted May 6 2 minutes ago, Eskimo Joe said: You laugh but wxtwitter is already calling bust thin linear line of storms in Kansas isn’t going to verify high risk 4 Link to comment Share on other sites More sharing options...
Powerball Posted May 6 Share Posted May 6 51 minutes ago, Powerball said: Agitated CU field has formed along the border of West OK and the TX Panhandle border. I would expect initiation in this area over the next 1-2 hours. And initiation is now underway... Link to comment Share on other sites More sharing options...
pbrussell Posted May 6 Share Posted May 6 3 minutes ago, Akeem the African Dream said: thin linear line of storms in Kansas isn’t going to verify high risk Have you even taken the time to read the forecast? 2 2 Link to comment Share on other sites More sharing options...
Toothache Posted May 6 Share Posted May 6 2 minutes ago, Akeem the African Dream said: thin linear line of storms in Kansas isn’t going to verify high risk But the majority of the high risk area is in Oklahoma and expected to really get bad with the llj? Maybe I'm missing the joke here 1 1 Link to comment Share on other sites More sharing options...
canderson Posted May 6 Share Posted May 6 10 minutes ago, Akeem the African Dream said: thin linear line of storms in Kansas isn’t going to verify high risk Well thank goodness SPC didn't, ya know, place that area of Kansas in a high risk category. 1 Link to comment Share on other sites More sharing options...
NorthArlington101 Posted May 6 Share Posted May 6 radar clear in Oklahoma TOR near Nashville, TN. Makes you think Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now