jojo762 Posted April 28, 2017 Share Posted April 28, 2017 2 minutes ago, Quincy said: What an April train wreck given what was a very promising start to the severe season through March. We may not only manage to have a flat late April (a period which generally produces at least one significant tornado event, even in most down years), but botch a large scale pattern that had so much potential. Bring on May. Not early May either, because that, as Brett eluded to, looks like a fail as well. GEFS/EPS/GEPS all still show mean western troughing toward May 7-11, obviously a long ways away... but still potential is there. Obviously that summer'esque ridge over the middle of the country is going to play a role in the evolution of any trough as well, in addition to any eastern trough that may exist. Link to comment Share on other sites More sharing options...
hlcater Posted April 28, 2017 Share Posted April 28, 2017 Of all people, Why is CoD hyping this event? It seems very unusual to see tweets like these from them. Seems like CoD has the ceiling set fairly high as far as what may transpire over the coming 48 hours. Link to comment Share on other sites More sharing options...
jojo762 Posted April 28, 2017 Share Posted April 28, 2017 I agree with their first tweet about potential late-night Friday tornadoes. Several CAMs this morning were showing that exact type of event. Strong WAA regime generally would favor this type of potential as well along/near the WF. Saturday is a tricky day, potential is there but its pretty conditional, not sure why they are going all in on it. Link to comment Share on other sites More sharing options...
Quincy Posted April 28, 2017 Share Posted April 28, 2017 4 minutes ago, jojo762 said: GEFS/EPS/GEPS all still show mean western troughing toward May 7-11, obviously a long ways away... but still potential is there. Obviously that summer'esque ridge over the middle of the country is going to play a role in the evolution of any trough as well, in addition to any eastern trough that may exist. I am cautiously optimistic about May week 2 and beyond, but barring something crazy tomorrow night, we may have one of the slowest five week early spring tornado stretches in quite some time. Link to comment Share on other sites More sharing options...
Quincy Posted April 28, 2017 Share Posted April 28, 2017 CoD may be getting trigger happy over pretty colors on their fixed-layer STP maps. (Wish they used effective layer) Although LLJ response does aid in poleward advance of moisture return overnight into early Saturday, good luck getting surface-based convection with forecast soundings like this: Wouldn't be surprised with a rogue tornadic supercell or two after midnight somewhere in the risk zone, but it's not looking like a nighttime outbreak by any stretch of the imagination. Link to comment Share on other sites More sharing options...
Santa Clause Posted April 28, 2017 Share Posted April 28, 2017 Are we referring to a let down West of I 35 or just system in general? Plenty of signs areas East could have some active severe. Link to comment Share on other sites More sharing options...
bubba hotep Posted April 28, 2017 Share Posted April 28, 2017 6 minutes ago, Quincy said: CoD may be getting trigger happy over pretty colors on their fixed-layer STP maps. (Wish they used effective layer) Although LLJ response does aid in poleward advance of moisture return overnight into early Saturday, good luck getting surface-based convection with forecast soundings like this: Wouldn't be surprised with a rogue tornadic supercell or two after midnight somewhere in the risk zone, but it's not looking like a nighttime outbreak by any stretch of the imagination. Some runs of the HRRRx have shown a broken line of semi-discrete cells across that area Link to comment Share on other sites More sharing options...
Quincy Posted April 28, 2017 Share Posted April 28, 2017 2 minutes ago, Wmsptwx said: Are we referring to a let down West of I 35 or just system in general? Plenty of signs areas East could have some active severe. East could be active for sure. The parameter space early Friday evening is very high end, climatologically, from AR to SE MO, W KY and S IL. The setup may look different meteorologically, but perhaps a similar geographic zone to 2/28/17 sees a few significant tornadoes? 1 minute ago, bubba hotep said: Some runs of the HRRRx have shown a broken line of semi-discrete cells across that area The window is definitely open from 00-03z and perhaps even an hour or two after that, but anyone hoping for a post midnight/pre-dawn tornado outbreak may be dissapointed. Link to comment Share on other sites More sharing options...
bubba hotep Posted April 28, 2017 Share Posted April 28, 2017 3 minutes ago, Quincy said: The window is definitely open from 00-03z and perhaps even an hour or two after that, but anyone hoping for a post midnight/pre-dawn tornado outbreak may be dissapointed. Yeah, just noticed that the HRRRx was doing that and matched up with the maps you showed. But then again, times don't look to match up Honestly, I haven't looked at anything in any detail in that area, more interested in seeing if something could fire in N. Texas tomorrow afternoon. But your advice applies there, disappointment for anyone looking for storms to take advantage of the huge CAPE across N. Texas. Link to comment Share on other sites More sharing options...
bdgwx Posted April 28, 2017 Share Posted April 28, 2017 HRRRX looks pretty mean at 6Z in OK. Surface parcels are capped pretty good so I too question the overnight tornado outbreak, but given the other severe parameters with convection breaking out it's looks likely they'll be an overnight outbreak of some kind at least if you believe the HRRRX. Edit: Oh, and that line of cells on the HRRRX along the MO/AR border look like they might be elevated. Link to comment Share on other sites More sharing options...
Quincy Posted April 28, 2017 Share Posted April 28, 2017 7 minutes ago, bubba hotep said: Yeah, just noticed that the HRRRx was doing that and matched up with the maps you showed. But then again, times don't look to match up Honestly, I haven't looked at anything in any detail in that area, more interested in seeing if something could fire in N. Texas tomorrow afternoon. But your advice applies there, disappointment for anyone looking for storms to take advantage of the huge CAPE across N. Texas. Can't completely rule it out either. Always keep at least a distant eye on a CAPE/shear overlay like that. On Tuesday, south-central OK big CAPE/shear and a cap bust was almost unanimously expected, but a cluster of junk managed to go up and led to a lone supercell early in the evening. Even with the mid-level wind issues in the 21-01z time-frame, crazy things can happen when you get extreme CAPE (>4000 J/kg) and just enough shear. The LLJ will improve into the night, so while it may not be chaser friendly, you can't completely rule out a rogue cell producing significant severe after dark, even as far west as parts of N TX/SE OK. Link to comment Share on other sites More sharing options...
jojo762 Posted April 28, 2017 Share Posted April 28, 2017 Just for posterity of how utterly ridiculously insane this low-level profile/hodograph is. I remember when the GFS a week or so ago was only showing the front dropping to just south of the Red River, and had it lifting back into southern Kansas as a warm front.... Sounding hodographs weren't quite THIS insane, but makes you wonder what could've been ): Been over 5 years since the last tornado-driven High Risk in the plains, and we definitely are not getting one for the foreseeable future... sigh... Note: For reference the highest 0-1KM SRH ever seen on a 12z/00Z RAOB at OUN in April is just above 700 m2/s2. Link to comment Share on other sites More sharing options...
jojo762 Posted April 28, 2017 Share Posted April 28, 2017 06Z SPC enhanced thunderstorm outlook doesn't even give a slight (10%) chance of thunderstorms in the main area between 20-00Z. Oof... Link to comment Share on other sites More sharing options...
jojo762 Posted April 28, 2017 Share Posted April 28, 2017 Nail in the coffin... SPC went with non-zero, 2% Tornado probability across OK/TX... higher probabilities further east across MO/KY/IN/IL. Ouch. Storms just aren't going to intiate soon enough and SBCINH is going to increase rapidly after dark... along with LLJ concerns. Very large hail will be a concern overnight nonetheless. Link to comment Share on other sites More sharing options...
1900hurricane Posted April 28, 2017 Share Posted April 28, 2017 Yeah, I'm probably not even heading out tomorrow, despite asking off work over a week ago. None of the members of the NCAR Ensembles convect in northwest Texas prior to sunset. I'll reevaluate in the morning after looking at some of the CAMs before making a final decision. The 00Z ECMWF maintains the boundary in ESE Texas during the afternoon on Saturday, and it appears that the 3 km NAM has begun to pick up on it as well. It's certainly raising my interest for a possible close to home chase. Link to comment Share on other sites More sharing options...
Santa Clause Posted April 28, 2017 Share Posted April 28, 2017 Feels weird we all spent this long for this low of probabilities. It seems like a year that a big event will come together on a slight day. Link to comment Share on other sites More sharing options...
SluggerWx Posted April 28, 2017 Share Posted April 28, 2017 10% TOR probs added to the revised Day 1 Outlook a couple hours ago. Also found this interesting: ...Overview... A notable potential exists for multiple impactful severe episodes this afternoon and tonight across a broad region characterized by increasing moisture, moderate to strong buoyancy and ample vertical shear. However, some of this risk is seemingly quite conditional and it should be noted that uncertainty is above average in terms of sub-regional spatial details and severe coverage. As such, more-than-typical spatial adjustments and refinements (including possible categorical and/or probabilistic upgrades) are plausible in subsequent Day 1 outlooks. Link to comment Share on other sites More sharing options...
jojo762 Posted April 28, 2017 Share Posted April 28, 2017 Well SPC expanded the 5% TOR back westward into SW OK to account for the conditional risk of CI, which would probably result in an intense supercell capable of all severe hazards. No other changes really as confidence is below average across most of the ENH risk area. Link to comment Share on other sites More sharing options...
WhiteoutWX Posted April 28, 2017 Share Posted April 28, 2017 I don't think the expansion was for conditional CI this afternoon but for intense supercells this evening that may have a chance at being surface based along the warm front. HRRR has been consistent in this scenario with a surprisingly low amount of SBCIN in the 04-07z time frame in the OKC area. Personally I think it may be underdoing the CIN but if a couple really intense supercells go up along the boundary it isn't out of the realm of possibilities for a couple tornadoes this evening. Link to comment Share on other sites More sharing options...
Santa Clause Posted April 28, 2017 Share Posted April 28, 2017 SPC being very smart and outlining potential without going all in. Link to comment Share on other sites More sharing options...
Indystorm Posted April 28, 2017 Share Posted April 28, 2017 10 minutes ago, Wmsptwx said: SPC being very smart and outlining potential without going all in. Yes. in light of the moderate risk bust they are being very prudent. Can always upgrade if conditions change. Link to comment Share on other sites More sharing options...
brettjrob Posted April 28, 2017 Share Posted April 28, 2017 12 minutes ago, WhiteoutWX said: I don't think the expansion was for conditional CI this afternoon but for intense supercells this evening that may have a chance at being surface based along the warm front. HRRR has been consistent in this scenario with a surprisingly low amount of SBCIN in the 04-07z time frame in the OKC area. Personally I think it may be underdoing the CIN but if a couple really intense supercells go up along the boundary it isn't out of the realm of possibilities for a couple tornadoes this evening. The modest SBCINH on the HRRR after dark over C OK caught my eye this morning, too. Nocturnal tornado threats in the Plains seem to be a mirage most of the time, but history says legitimate multi-storm events/outbreaks do happen every so often. I'm not expecting that tonight, but the threat for a tornado or two in the 03z-06z timeframe looks above average. The 12z NAM also depicts minimal CINH at 03z over a wide swath of the OK warm sector. Link to comment Share on other sites More sharing options...
okiestormgeek Posted April 28, 2017 Share Posted April 28, 2017 Just now, Indystorm said: Yes. in light of the moderate risk bust they are being very prudent. Can always upgrade if conditions change. Is the warm front moving further north than anticipated before? Link to comment Share on other sites More sharing options...
Indystorm Posted April 28, 2017 Share Posted April 28, 2017 2 minutes ago, okiestormgeek said: Is the warm front moving further north than anticipated before? Enhanced risk hasn't changed much but 5% tor probs were extended westward, so I would say that WF position is pretty much going according to expectations at present. Link to comment Share on other sites More sharing options...
andyhb Posted April 28, 2017 Share Posted April 28, 2017 I can't help but marvel at the amount of things that have come together to mitigate the potential over basically this entire stretch. Wednesday trough too amplified leading to messy wind profiles -> also leads to surging cold front removing any of Thursday's potential -> early shortwave passage leads to veering/weakening of the low level flow further west today -> late timing of the primary upper trough leads to problems with the cap before dark -> amplification by Saturday leads to excess upper level divergence and poor mid/upper level wind profiles unfavorable for non-linear/non-HP storm modes. That is one heck of a laundry list that no forecaster 5+ days out would've seen coming (or even anticipated closer in frankly). Link to comment Share on other sites More sharing options...
Superstorm93 Posted April 28, 2017 Share Posted April 28, 2017 45% un-hatched ENH risk on the D2 Mentions gratuitous amount of convection and likely linear convective modes. Link to comment Share on other sites More sharing options...
WhiteoutWX Posted April 28, 2017 Share Posted April 28, 2017 17 minutes ago, andyhb said: I can't help but marvel at the amount of things that have come together to mitigate the potential over basically this entire stretch. Wednesday trough too amplified leading to messy wind profiles -> also leads to surging cold front removing any of Thursday's potential -> early shortwave passage leads to veering/weakening of the low level flow further west today -> late timing of the primary upper trough leads to problems with the cap before dark -> amplification by Saturday leads to excess upper level divergence and poor mid/upper level wind profiles unfavorable for non-linear/non-HP storm modes. That is one heck of a laundry list that no forecaster 5+ days out would've seen coming (or even anticipated closer in frankly). Yep pretty much a perfect storm screwjob Link to comment Share on other sites More sharing options...
Santa Clause Posted April 28, 2017 Share Posted April 28, 2017 Honestly still looks likely for some significant severe, just not TOR. Link to comment Share on other sites More sharing options...
okiestormgeek Posted April 28, 2017 Share Posted April 28, 2017 1 minute ago, Wmsptwx said: Honestly still looks likely for some significant severe, just not TOR. There are some local amateur mets in the OKC area predicting a few significant tornadoes in the C OK tonight. Link to comment Share on other sites More sharing options...
huronicane Posted April 28, 2017 Share Posted April 28, 2017 11 minutes ago, okiestormgeek said: There are some local amateur mets in the OKC area predicting a few significant tornadoes in the C OK tonight. Because we know that they are putting heavy emphasis on getting out the most accurate information Link to comment Share on other sites More sharing options...
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