Jump to content

Quincy

Meteorologist
  • Content count

    5,497
  • Joined

  • Last visited

About Quincy

  • Birthday 02/03/1987

Contact Methods

  • Website URL
    http://www.quincyvagell.com

Profile Information

  • Four Letter Airport Code For Weather Obs (Such as KDCA)
    KOKC
  • Gender
    Male
  • Location:
    Oklahoma City, OK

Recent Profile Visitors

4,412 profile views
  1. Napril Fools? Pattern and Model Discussion . . .

    The PV might get displaced to Hudson Bay, if not farther south, by next weekend. More snow atop KTOL? ASOUT.
  2. I don't think anyone's calling the entire season over, at least not without some sarcasm. We all realize that even in the worst storm chasing seasons, there are usually at least a couple of events/stretches that perform between mid-May and mid-June. What we have here is increasing confidence that the next 1-2 weeks will probably be unseasonably quiet. That says a few things: Since the ensembles and CFS dashboard have pretty good verification stats inside of 2 weeks, there is near-certainty that the next 1-2 weeks will be relatively quiet. It's pretty unusual to go through the last two weeks of April without a higher end outbreak and/or several active severe weather events. 4/29, 4/30 in 2017 4/26 in 2016 (with several other active days in late April) 4/26 in 2015 was a small moderate risk with a localized outbreak, but there were several events over the Plains from 4/16 through 4/26. 4/27, 4/28 in 2014. Yes, most of that was east of the Plains, but 4/28 was a high-end tornado outbreak in Dixie. 2013 was pretty blah, although there were modest events in Oklahoma on 4/17 and 4/26, a widespread wind event across the East Coast on 4/19 and fairly widespread large hail (with some significant) in Iowa on 4/30. 4/30 in 2012 was a decent event in the Plains and other days that come to mind are 4/21 with a several tornadoes in the Upper Midwest and 4/26 through the end of the month was a relatively active period in the Plains/Midwest. Recall that 2012 had a historic severe weather sequence earlier in the month... I don't think I really need to go into detail about 2011... 4/22 in 2010 featured a High Plains severe weather outbreak with modest events on 4/23, 4/24, 4/29 and 4/30. If you want to count an event in the mid-Atlantic, include 4/25. 2009 had several small to medium sized events all throughout the last two weeks of April. 2008 had tornadoes in 9 out of the last 14 days of April and while no single event sticks out as a "big one," 4/23 featured severe weather over a broad portion of the Plains with a localized outbreak in Texas, while 4/24 was a moderate risk/localized outbreak in the central Plains. This is just the past ten years and if you want to be a purist and say that tornado chasing in the Plains isn't always great in late April, you'd be correct, but this sub-forum includes areas farther east and the general discussion is severe weather in the central U.S. It's not "this is a thread that's only for tornado chasing west of I-35." Since tornado probabilities are rapidly increasing through late April, the quieter it is now, the more below average the year-to-date tornado count will fall. It is possible that a few days around the end of April could heat up, but confidence is very high that the next 7-10 days will be unusually quiet on the broad scale. The record for the longest start to a year ever with no tornadoes in Oklahoma is in jeopardy. After finishing today with no tornadoes, that places 2018 into a tie with 1970 with no Oklahoma tornadoes through April 18th of a year, dating back to 1950. There are still 8 more days to go to tie the record of April 26th, 1962, but one could argue that the odds of breaking that record are better than not breaking it, based on the synoptic pattern expected through the 26th. If you want to be a storm chasing purist or look at this from a chasecationing angle, then yes, the heart of the season is still out of range of most modeling and for all we know, could end up being very active. With that said, we've seen a trend this year for a lousy pattern and just about everything has gone wrong. Since 2012, 4 out of the last 6 years have been fairly dull, overall, in May and June. 2016 was fairly active in May, but then the pattern basically shut down for June. 2013 was pretty much garbage the entire year, aside from the second half of May and then two single days in the fall. Climate goes through ups and downs. Overall, the Plains has been on the bottom end of a roller coaster ride for several years now. I think seasons like 2008 and 2011 may skew some of our thinking. High-end events are relatively rare, but sway the mean. The result is that more than half of years will have "below average" tornado counts, but the years that are above average can be way above average, skewed by high-end outbreaks. On a personal note, this may be the first month of April that I don't have any storm chases since I started spring chasing in 2014. That says a lot, considering I live in Oklahoma now and in 2014-2016, I lived on the East Coast. I basically played climatology those years and did not even open up my schedule to storm chase during the first half of April. The bright side is that I haven't had too many highly successful chases in April yet, so from a storm chasing perspective, the season still has a long way to go.
  3. The 12z EPS is pretty awful, with Great Lakes troughing right through day 15.
  4. I actually looked closer at the data tonight and it's downright ugly. The weeklies show AOA 500mb heights over the central/southern Plains for 35 out of 36 days between 4/26 and 5/31. The CFS has all blue chiclets through May 3rd. (The CFS is not God, but it has support from other data) Overall synoptic pattern advertised on the GEFS/EPS over the next two weeks is not favorable. To be cautiously realistic, there is some potential for the pattern to amplify a bit around the last weekend in April, but even there, some ensembles suggest that we get some sort of cutoff low over the California region, which would not be very favorable either. Overall, the next two weeks, at least, look quiet. One cannot rule out one or two days that either overperform or come up on short notice, but aside from that, I'll go back to sleep as well.
  5. At least we should finally start backing out of the historic fire weather concerns and exceptional drought in the southern High Plains. The operational models and ensembles are in very good agreement for at least 0.5-1 inch of rain by Friday night over a broad area that has seen virtually no meaningful precipitation since last fall.
  6. Sounding climatology suggests that 60F dew-points would be high-end for the time of year. MAF sounding climo suggests a 55F dew would move into the 90th percentile, while lower 60s is the max for the 64+ year period of record. At AMA, 50F is already well above the 90th percentile, with almost no soundings eclipsing 60F dews in April. Remember that West Texas has a similar elevation to the CO/KS border region, as higher terrain does not necessitate higher dew-points as lower terrain areas. Dew-points in the mid and especially upper 50s would be sufficient. Mean mixing ratios of 11+ g/kg (which GFS shows) will get it done. With that said, I don't think there's any reason to believe this will be a major event, but it certainly has the ingredients for a respectable April event in the High Plains, assuming storms remain at least somewhat isolated. Let's keep an eye on it and see how moisture return looks. If it trends lower than it is now, then maybe we'll have a problem. At the very least. the setup should bring some much needed rain to the panhandle region, which has been plagued by a major drought and destructive fire season as of late.
  7. The overall risk area was fine. I wouldn't nitpick over the 15% tor in the Arkansas vicinity. The general idea was there, as it was on 4/27/14. As far as tornado probabilities farther north (north of TUL-SGF), the data simply did not support much of a tornado threat in the region. I think the wind fields were more of an issue than low level moisture, but it's a moot point now. It's not uncommon at all for significant tornado threats 200-300+ miles away from the center of a low, where weaker (but still sufficient forcing) coincides with larger buoyancy and longer residence time of discrete/semi-discrete storm modes. This could have been a higher-end event, as Andy eluded to, if the upper level system had arrived a little bit later.
  8. Which model has that much 0-1km SRH? The 3km NAM has 100-200 m2/s2 immediately ahead of the dryline (storm-scale environments lead to locally, slightly higher values) and I said that was lower-end for long-track tornadoes. VBV can limit updraft organization, as updrafts get sheared and have shorter residence times than you'd see with a larger hodograph. Mean wind fields that are unidirectional or sloppy (VBV) in the 2-6km layer are not often associated with regional tornado outbreaks. Tornadoes? Yes, there will probably be multiple, but there is not much data to suggest there will be numerous long-track tornadoes, just as the analog data alone suggests a questionable threat of a significant or widespread tornado event. There is a reason for that. We've seen better wind profiles struggle to produce any tornadoes, so we'll see. Tornadogenesis is most concerned with low-level shear, but in order for long-lived supercells, the mid and upper level support would need to be improved. Back to analogs again as well, it's not just the CIPS analogs. Look at forecast soundings up and down the dryline. There are very few matching analogs that were associated with significant tornado events/outbreaks.
  9. I'm not really sold on the long-track tornado potential. The low level shear is decent and while low-end for long-track tornadoes, could be supportive, if there weren't other red flags to be concerned about. Yes, storm motions should be on the speedy side, on the order of 50 knots or faster and most of the SRH will be confined to the lowest kilometer, but the latter is overshadowed by unidirectional winds in the 2-6km layer, not to mention some backing in the upper levels and some forecast soundings showing kinky (subtle VBV) signatures in the mid-levels. The deep layer shear vector is out of the SW and the dryline orientation should largely be north-south, so there is some crossover, but it's not as perpendicular as you would like to see for a long-track tornado event. The wind profile seems to suggest that any discrete cells may have trouble maintaining organization for extended periods of time. Also looking at analogs, it's actually a bit surprising how low the tornado probabilities are. Using a NAM-based analog, only about 20-30% of the top 15 analogs had at least one tornado report within a 110km of a gridpoint via CIPS. Furthermore, less than 10% of the top analogs had at least one long-track tornado event. There's little doubt that there is some "enhanced" tornado potential given the degree of low-level shear, but the setup doesn't look ideal for long-lived, tornadic supercells. Farther south across the threat zone, into eastern Oklahoma and eastern North Texas, the mid and upper level wind profiles are somewhat better and there will be more instability there, but capping and weaker forcing may work to offset that.
  10. The 12z Euro shows a similar scenario to the NAM, based on limited precipitation fields, suggesting that there may very well be a number of discrete/semi-discrete cells in eastern Kansas and eastern Oklahoma, immediately ahead of the dryline. I wonder if the veer-back-veer signature in the wind fields may be a factor in limiting updraft strength/longevity. Either way, it does seem like the squall line scenario is increasingly unlikely, but it should be noted that the NAM still erodes most of any lingering capping by early afternoon along the dryline, so there's no reason to believe there wouldn't be convection.
  11. The models are converging and a severe weather event is appearing increasingly likely on Friday, particularly from eastern portions of the southern Plains into parts of Arkansas, Missouri and possibly Iowa. Models bring a seasonably strong surface cyclone from the central Plains Thursday night to a position in the lower Missouri Valley vicinity by Friday evening. Ahead of a cold front, a plume of low to mid-60s dew-points is favored in the warm sector likely covering much of Missouri, eastern Kansas, eastern Oklahoma, Arkansas and East Texas. This would support at least a narrow zone of moderate instability, i.e. CAPEs of at least 1000-2000 J/kg, particularly along areas from eastern Kansas, southward to East Texas, immediately ahead of the cold front. Due to cooling aloft, an upper level low approaches, convective initiation is expected during the afternoon with little to no capping, in a broad swath immediately ahead of the cold front and possibly in the open warm sector as well. It should be noted that the size of the warm sector is a bit of a question mark, leaving the greatest confidence to convection closer to the cold front. Areas displaced farther east may see more capping, along with less influence from the attendant upper level trough. More than adequate deep layer shear for severe thunderstorms is a given with a >70 knot jet streak rounding the base of the upper level trough. Probably the biggest issue limiting this from a more widespread tornado threat is the largely unidirectional wind fields in the mid and upper levels. Forecast soundings up and down the region from southern Iowa to East Texas show relatively straight hodographs in the 1-6km layer, with some subtle veer-back-veer signals as well. With that said, there is enlargement of 0-1km hodographs, as near-surface winds ahead of the southwesterly mid/upper level flow should be S to SSE in the warm sector. Take it with a grain of salt, but NAM forecast soundings in a wide area do show a bit of a sickle-shape in the 0-1km portion of the hodograph, but show kinks in the mid-levels. There may even be a tendency for winds to back a bit above 500mb, so the lack of a more veering-with-height throughout the column profile suggests there are some limiting factors in place in respect to tornado potential. There is some concern that convection may develop quickly over a broad area Friday afternoon with a tendency for storms to merge into line segments. Unlikely some recent severe weather events, mid-level lapse rates appear more modest, so large hail will probably be overshadowed more by the threat for damaging winds and isolated tornadoes. In terms of storm chasing potential, the threat one does not exactly look to fall over favorable terrain, but there is some silver lining. Assuming the model progs do not speed up the system, then eastern Kansas may get in on the action. Eastern Oklahoma and other points east are far from ideal. The Iowa vicinity is a bit more of a wildcard, depending on how the surface low evolves. If a more wound-up low moves across Iowa, there could certainly be a play near the surface low/triple point. If the low is more elongated, like some data suggests, then I would be concerned about limited instability and messier storm modes with northward extent. Mesoscale details can be ironed out as the event nears, but the general area surrounding the AR/KS/MO/OK border region seems to have the greatest likelihood for severe thunderstorms, near and just ahead of the cold front. Issues arise further north (Iowa) and it's unclear how convection may evolve farther south, away from stronger large-scale forcing (East Texas). Given the synoptic pattern, at least scattered severe reports (including all hazards of hail, tornado and wind) are likely. Storm mode expectations lead me to believe that the window for tornadic supercells and large hail may be relatively narrow, but wind fields suggest that brief tornadoes may remain a possibility later in convective evolution, even if storms consolidate into a line or line segments. Damaging wind could end up being the more widespread story, given the strength of the expected wind fields.
  12. This Thursday/Friday storm system is kind of funny. Instead of being upset or depressed with the following scenario, I actually take a moment to chuckle and move on. It's not worth it getting upset over a lousy pattern. Assuming the latest models are close to right, both the GFS and Euro take a <982mb low from west to east across Nebraska Thursday evening into the overnight. Despite such a strong surface cyclone so far north, the Euro struggles to bring 60F dew-points to the Kansas border by 00z Friday, while the GFS does manage to bring dews into the lower 60s as far north as Kansas City. All else put aside, if someone said that a deepening 982mb low was going to move across Nebraska in mid-April, the alarm bells would probably be going off for a potential severe weather event. Since temperatures aloft are going to be quite warm and low-level moisture will be lower-end for the setup, it's probable, if not likely, that no convection will initiate in the Plains on Thursday. Sure, the event is still several days out and if the low-levels improve a bit, there's still a shot at something conditional, but it looks like Thursday will probably be wasted. If that wasn't bad enough, Friday has better potential, but the warm sector will be relatively narrow, the best forcing becomes farther displaced from areas with more favorable buoyancy and most, if not all of the convection should initiate over "poor" terrain in the Arkansas/Missouri vicinity. Too slow for Thursday to be promising and probably too sloppy of a setup for a bigger event on Friday. It's also slowed down and shifted enough west that the corn belt region will likely be on the cooler side of the setup, rendering any severe threat close to zero there. The weekend looks like another trough over the eastern third of the U.S., but there are signs that the pattern gradually becomes more conducive for severe weather in the central states by the following week. That's not saying a lot given the calendar, but as it stands, it still looks like nothing major in the foreseeable future. We had snow yesterday and now the models show temperatures in the 90s to around 100F for parts of western Oklahoma on Thursday.
  13. Daytime accumulating snow here in Oklahoma City. Pretty remarkable for April 7th. Still 26F at noon, despite an average high of 70F. According PSU e-WALL data, the temperature is 37F below average for 17z.
  14. 2018 Short to Medium Range Severe Thread

    I said that it doesn't look like anything "big" at that point. Yeah, a surface low below 990mb over the central Plains is pretty impressive, but with an event so many days out and models continuing to evolve on the details, I'm not getting overly excited yet. Taken literally, the latest 12z Euro is pretty impressive across portions of Arkansas/Kansas/Missouri/Oklahoma next Friday, but that's seven days out. Earlier model progs were faster and some showed potential Wednesday and Thursday over the Plains, while the warm sector on Friday was progged to be fairly narrow across the Midwest. Now, it's slowing down and adjusting west a bit. This may have switched from an Iowa/Illinois/Missouri event, back into the Plains/Ozarks. Since it's a week out, there's a lot more room for things to change. The synoptic pattern does favor severe weather, but with model disagreement and still at least some issues about downstream troughing over the Northeast, there is not a lot of wiggle room. In years like 2011, due to the persistent early spring pattern and ridging over the eastern U.S., storm systems went nuts over a large area. This year, especially with it still being relatively early in the season, you do have to wonder about the size of the warm sector and moisture transport with northward extent. Having an intense surface cyclone may help offset some of those concerns a bit, but there is a reason why SPC did not highlight a risk zone yet in their extended outlook. Let's see how it evolves. Yeah, I'm a bit biased toward the Plains, but if something big shows up for areas east of the Mississippi River (I drove overnight to Alabama for the March 19th event...), I'm still going to have my interest piqued. If the last few years have taught us anything, it's to not get too excited 7+ days out from a potential event, especially with details. A lot can and often will go wrong, unless a historic event is expected, then models often tend to zero in on the threat many days in advance. While the surface low itself looks impressive, the synoptic upper level pattern is similar to what you'd expect to see at least once or twice a year in April. It's nothing to write off, but for many reasons, it does not look like a major event at this time. Model variability is huge. The 12z Euro on Wednesday had a 970mb low in eastern Iowa at 18z Friday, while today's run has a 985mb low over the Colorado/Nebraska border at the same time. Extrapolate that out another few days and it's easy to see how much more models could change.
  15. Assuming the model prog is correct, it's just a messy setup with a cold front crashing south from Oklahoma. Soundings ahead of the front show a monster cap near the Red River and into East Texas, although that is less of a problem up into Arkansas near the warm front. In such a scenario, we'd probably see a big squall line with perhaps a few embedded supercellular elements, but definitely HP. I also don't like the looks of limited CAPE in the lowest 2-3km. So far this year, we've had no problem driving the EML eastward with impressive 700-500mb lapse rates (probably dry air punching farther east with the ongoing High Plains drought and cold intrusions from the north), but a lot of the setups so far have had limited low-level CAPE. I guess that's to be expected until we're later in the season and it's easier to get surface temperatures into the 80s.
×