weatherextreme Posted April 21, 2017 Share Posted April 21, 2017 This is still a week away, however, the SPC already has this day pinned for a day 8 potential significant severe weather event. Edit :Map Update to reflect current date of 4/27/17 ...Friday/Day 8... The ECMWF and GFS are in better agreement in the western U.S., developing a vigorous upper-level trough in the Four Corners region. This coincides with strong moisture advection across the Great Plains. The synoptic setup which the medium-range models have been forecasting for a couple days, could result in a significant severe weather event on Friday into Friday night across parts of the southern and central Plains with tornadoes, large hail and wind damage possible. Due to the potential for a higher-end event on Friday, have added a 15 percent contour where model consensus places the greatest chance of severe weather. Link to comment Share on other sites More sharing options...
MattPetrulli Posted April 21, 2017 Share Posted April 21, 2017 May have to change the title to fit an all week event. GFS/Euro would be one of the bigger outbreak sequences we have seen in a long time. Link to comment Share on other sites More sharing options...
Quincy Posted April 21, 2017 Share Posted April 21, 2017 Might as well change the title to ~Mon-Sat 4/24-29 or even just "late April" severe threats. Expect multiple opportunities for severe across the central U.S. Knowing how these things can unfold, we could easily get a bigger day prior to next Friday, and/or the outlook for the 28th could end up evolving synoptically different than currently anticipated. Link to comment Share on other sites More sharing options...
TheBudMan Posted April 21, 2017 Share Posted April 21, 2017 Heading out to Chicago next week - any chance I can see some good action out there or will all the good action be way south of me ? Link to comment Share on other sites More sharing options...
tornadohunter Posted April 21, 2017 Share Posted April 21, 2017 2 minutes ago, TheBudMan said: Heading out to Chicago next week - any chance I can see some good action out there or will all the good action be way south of me ? There are multiple chances in Illinois over the next 10 days. As noted in other threads, on going convection could be a problem though Link to comment Share on other sites More sharing options...
jojo762 Posted April 21, 2017 Share Posted April 21, 2017 I'm tending to like the potential on Wednesday /Thursday better than Friday, probably Thursday as cyclogenesis occurs farther north and the LLJ is much more impressive... The cap is concerning for Thursday, but that might work in our favor and produce isolated supercells, compared to Friday where we will see heaping loads of storms. On Friday the potential for meridonial flow and VBV is concerning, lots of deleterious storm interactions, but the strength and direction of the low-level flow lends credence to a higher-end tornado threat regardless... 5/24/11 featured a lot of storms and storm interactions if I recall... obviously this is based off of current model depictions, namely the op gfs, and things will evolve. Many of the GEFS ensembles as well as the euro FWIW don't really show meridional flow quite like the GFS does... so that's positive. Link to comment Share on other sites More sharing options...
CGChaser Posted April 21, 2017 Share Posted April 21, 2017 Most likely issued Day 8 as Euro prefers Friday > Thursday. Still time for change, but the stretch late next week, possibly into early May looks active. Link to comment Share on other sites More sharing options...
Superstorm93 Posted April 21, 2017 Share Posted April 21, 2017 14 minutes ago, CGChaser said: Most likely issued Day 8 as Euro prefers Friday > Thursday. Still time for change, but the stretch late next week, possibly into early May looks active. Yeah, I'd day that'd a reasonable guess. Link to comment Share on other sites More sharing options...
Superstorm93 Posted April 21, 2017 Share Posted April 21, 2017 EPS Link to comment Share on other sites More sharing options...
weatherextreme Posted April 21, 2017 Author Share Posted April 21, 2017 Link to comment Share on other sites More sharing options...
bjc0303 Posted April 21, 2017 Share Posted April 21, 2017 2 hours ago, jojo762 said: I'm tending to like the potential on Wednesday /Thursday better than Friday, probably Thursday as cyclogenesis occurs farther north and the LLJ is much more impressive... The cap is concerning for Thursday, but that might work in our favor and produce isolated supercells, compared to Friday where we will see heaping loads of storms. On Friday the potential for meridonial flow and VBV is concerning, lots of deleterious storm interactions, but the strength and direction of the low-level flow lends credence to a higher-end tornado threat regardless... 5/24/11 featured a lot of storms and storm interactions if I recall... obviously this is based off of current model depictions, namely the op gfs, and things will evolve. Many of the GEFS ensembles as well as the euro FWIW don't really show meridional flow quite like the GFS does... so that's positive. The GFS operational run is probably developing too quickly, as we've seen often. The GFS' own ensemble seems to support Friday more than Thursday, granted there is considerably spread. ECMWF and especially EPS favor Friday, and as someone else said this is probably why Friday is highlighted on the day 4-8 outlook. The EPS is actually pretty damn impressive in its agreement based on anomaly forecast and graphic posted above. I definitely lean Friday myself. Link to comment Share on other sites More sharing options...
jojo762 Posted April 21, 2017 Share Posted April 21, 2017 True... GFS always has those issues it seems, 12Z euro remained steady-state for Friday depicting a major severe threat across the I-35 corridor in OK/KS, as did the 12Z GEM FWIW. Link to comment Share on other sites More sharing options...
bdgwx Posted April 21, 2017 Share Posted April 21, 2017 It's not unusual for patterns like this to yield multi day outbreaks and at this range it's hard to pinpoint any one particular day as being better than another at least based off of ensembles alone. I don't know how many times I've seen day X jump out me on a deterministic model run at this range only to have day X-1 or X+1 actually be the big boy. So at this point the I'm just keeping my eye on the 27th through 30th though . One thing I imagine we all agree on is that ensembles and deterministic modeling have a very strong signal for an uptick in activity during this time period. Link to comment Share on other sites More sharing options...
Misstertwister Posted April 21, 2017 Share Posted April 21, 2017 Heidi ho weather folks!! This coming week looks interesting. Per SPC focus is obviously Friday. Has anyone looked at recent GFS run at 18Z for 00Z Saturday? im very much an amateur or less than that when reading but it looks like it has shifted way south and east per EHI? Am I wrong? What else should I look at? i know this will change a lot until the event gets closer thanks Link to comment Share on other sites More sharing options...
jojo762 Posted April 22, 2017 Share Posted April 22, 2017 1 hour ago, Misstertwister said: Heidi ho weather folks!! This coming week looks interesting. Per SPC focus is obviously Friday. Has anyone looked at recent GFS run at 18Z for 00Z Saturday? im very much an amateur or less than that when reading but it looks like it has shifted way south and east per EHI? Am I wrong? What else should I look at? i know this will change a lot until the event gets closer thanks The Operational GFS is currently faster than pretty much every other model, and develops the system faster so it moves the front east much faster than the euro or GEM by friday. I wouldn't pay too much attention to any one run from one model at this point. The GEFS/EPS/Euro/GEM still support friday being a potentially big day further west toward the I-35 corridor. If every model and the ensembles start to trend toward a faster evolution, then it might be something to pay attention to, and perhaps Thursday could be a bigger day then. Link to comment Share on other sites More sharing options...
MattPetrulli Posted April 22, 2017 Share Posted April 22, 2017 2 hours ago, jojo762 said: The Operational GFS is currently faster than pretty much every other model, and develops the system faster so it moves the front east much faster than the euro or GEM by friday. I wouldn't pay too much attention to any one run from one model at this point. The GEFS/EPS/Euro/GEM still support friday being a potentially big day further west toward the I-35 corridor. If every model and the ensembles start to trend toward a faster evolution, then it might be something to pay attention to, and perhaps Thursday could be a bigger day then. Another thing to point out that GFS didn't handle today too well and overdid it some. Link to comment Share on other sites More sharing options...
MattPetrulli Posted April 22, 2017 Share Posted April 22, 2017 00z GFS is quite the setup Thursday evening in OK..... Link to comment Share on other sites More sharing options...
jojo762 Posted April 22, 2017 Share Posted April 22, 2017 11 minutes ago, MattPetrulli said: 00z GFS is quite the setup Thursday evening in OK..... hr144 from the 00Z GFS for thursday has a eerily similar look to what the 12z euro had for hr180 on friday... DL and WF location and orientation, H5 trough/flow orientation, along with the explosive CAPE and ridiculous low-level hodos. Only the Euro had more CAPE. Believe the 12Z Euro verbatim had ~600m2/s2 ESRH at OKC at 7pm next friday. Not like details like this are relevant at all right now, just interesting and crazy what models are putting out right now... Link to comment Share on other sites More sharing options...
MattPetrulli Posted April 22, 2017 Share Posted April 22, 2017 2 minutes ago, jojo762 said: hr144 from the 00Z GFS for thursday has a eerily similar look to what the 12z euro had for hr180 on friday... DL and WF location and orientation, H5 trough/flow orientation, along with the explosive CAPE and ridiculous low-level hodos. Only the Euro had more CAPE and slightly more impressive SRH. Believe the 12Z Euro verbatim had ~600m2/s2 ESRH at OKC at 7pm next friday. Not like details like this are relevant at all right now, just interesting and crazy what models are putting out right now... Yeah either one of these days or both could really go up and be big. All depends on smaller features though, still a week out. Link to comment Share on other sites More sharing options...
jojo762 Posted April 22, 2017 Share Posted April 22, 2017 Just for the sake of the lolz, and for posterity for what the 00z GFS looks like for thursday across NC OK... Bullseye hunting. lol. Save this, as its probably one the most "weather porn" soundings you'll ever see. Link to comment Share on other sites More sharing options...
CGChaser Posted April 22, 2017 Share Posted April 22, 2017 4 minutes ago, jojo762 said: Just for the sake of the lolz, and for posterity for what the 00z GFS looks like for thursday across NC OK... Bullseye hunting. lol. Save this, as its probably one the most "weather porn" soundings you'll ever see. Yep. Found that one in my backyard literally. lol. See what Euro shows. GFS even had trouble today just 36hrs ago.. Link to comment Share on other sites More sharing options...
weatherextreme Posted April 22, 2017 Author Share Posted April 22, 2017 17 hours ago, Quincy said: Might as well change the title to ~Mon-Sat 4/24-29 or even just "late April" severe threats. Expect multiple opportunities for severe across the central U.S. Knowing how these things can unfold, we could easily get a bigger day prior to next Friday, and/or the outlook for the 28th could end up evolving synoptically different than currently anticipated. Done Link to comment Share on other sites More sharing options...
Hoosier Posted April 22, 2017 Share Posted April 22, 2017 41 minutes ago, jojo762 said: Just for the sake of the lolz, and for posterity for what the 00z GFS looks like for thursday across NC OK... Bullseye hunting. lol. Save this, as its probably one the most "weather porn" soundings you'll ever see. Meh... the speed shear sucks between 850-400 mb. Link to comment Share on other sites More sharing options...
Chinook Posted April 22, 2017 Share Posted April 22, 2017 That's an EHI of 18.98 Link to comment Share on other sites More sharing options...
Quincy Posted April 22, 2017 Share Posted April 22, 2017 00z Euro shows Friday as more of an in between day now (between shortwaves) with more apparent threats on Thursday and Saturday. Expect more fluctuations with time. Bottom line: Multiple days of severe weather remain probable this upcoming week across the sub-forum. Link to comment Share on other sites More sharing options...
Superstorm93 Posted April 22, 2017 Share Posted April 22, 2017 ...Thursday/Day 6... As with previous runs, the ECMWF ejects a lead shortwave trough across the central Plains on Thursday/Day 6 while the GFS maintains an upper-level trough further west in the Four Corners region. Both solutions surge a moist high-quality airmass northward into the southern Plains and develop a well-formed dryline by late afternoon. In spite of the differences at 500 mb, both solutions move a mid-level jet over the moist sector as a low-level jet strengthens during the early evening. This setup suggests a higher-end severe weather event will be possible in the southern and central Plains during the late afternoon and evening with a potential for tornadoes, large hail and wind damage. ...Friday/Day 7... The ECMWF and GFS solutions continue to develop an upper-level trough in the Four Corners region on Friday/Day 7 as a mid-level jet ejects out of the base of the trough into the southern and central Plains. The GFS maintains a high-quality moist sector over the southern Plains Friday afternoon and evening while the ECMWF waits until the overnight period to surge moisture northward across the Southern Plains. Both of these solutions would be favorable for a severe weather event in parts of the southern and central Plains Friday or Friday night. A higher-end severe weather event will be possible with supercells and a potential for tornadoes, large hail and wind damage. Link to comment Share on other sites More sharing options...
pbrussell Posted April 22, 2017 Share Posted April 22, 2017 10 hours ago, jojo762 said: Just for the sake of the lolz, and for posterity for what the 00z GFS looks like for thursday across NC OK... Bullseye hunting. lol. Save this, as its probably one the most "weather porn" soundings you'll ever see. Link to comment Share on other sites More sharing options...
andyhb Posted April 22, 2017 Share Posted April 22, 2017 06z GFS suppressing everything after that lead wave passes through on Tuesday/Wednesday. That would be quite the mitigation of the threat. Link to comment Share on other sites More sharing options...
Jim Martin Posted April 22, 2017 Share Posted April 22, 2017 Just seems like the moisture return is not as great on this run of the GFS. Model Madness continues. Link to comment Share on other sites More sharing options...
jojo762 Posted April 22, 2017 Share Posted April 22, 2017 43 minutes ago, andyhb said: 06z GFS suppressing everything after that lead wave passes through on Tuesday/Wednesday. That would be quite the mitigation of the threat. 12Z GFS is similar.. but not quite as bad as 06Z. Bleh. Guess we'll see what the euro has to say. Link to comment Share on other sites More sharing options...
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