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About Quincy

  • Birthday 02/03/1987

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    Oklahoma City, OK

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  1. With some issues WRT placement and timing and key features, it will probably be another day or so before we get more clarity on Wednesday's threat. (Tuesday looks like a cap bust in this sub-forum) I do see increasing potential for overnight/morning warm sector storms moving into the Ohio Valley by early Wednesday, followed by a muddled/messy second round of storms later in the day. Perhaps a Friday do-over with a somewhat more favorable setup?
  2. While the instability/shear overlay is fairly impressive for late February over the Arkansas vicinity, no focused area of forcing seems apparent until well after dark. Confidence is not high in 22-01z initiation over AR, but if such a scenario was realized, there could be a significant supercell or two. The 4km NAM does show a bit of a VBV signature in the 1-3km AGL layer around AR, while a stout cap makes initiation over MO/IL even more questionable. Given the parameter space, it may be wise to wait a few more model runs to get into specifics, as it could be another big or bust type setup. I could see a situation where robust storms develop overnight or early Wednesday, as sizable CAPE advects northeast and the LLJ really ramps up.
  3. It's still early in the season. It's not particularly common for events in the Plains or Ohio Valley through about mid-March, aside from outlier outbreaks. Limited moisture is a glaring issue, unless you get a string of anomalously strong surface lows diving north into the Upper Midwest. The early signs have been encouraging at the least. While we may quiet down a bit upon finishing up February, I am looking ahead in a cautiously optimistic manner. About two months into the year, we've seen the most early season tornadoes since 2008. Even if we flatline for the next two weeks, we'll still be above climo, year-to-date.
  4. A little bit more active up north than 3/13/06, but given the generally sporadic nature of severe reports, I'd argue the ENH risk didn't/won't verify. As mentioned earlier, the lack of a well-defined prefrontal trough markedly lowered the warm sector supercell tornado potential. It was simply too early in the season (think moisture) for a notable warm front threat. The only thing that could have offset the calendar would have been a much stronger than forecast surface low. Veering winds coupled with a contaminated warm sector didn't help either, but SPC did a fair job in the short-term, opting for a severe thunderstorm watch over a tornado watch.
  5. Winds have largely veered to SW across IN/OH, with the exception being up in far northern IN. Southern MI looks okay too with better low level turning/SRH. There are signs that some backing may take place by late afternoon a bit downstream, but for the next couple of hours, the setup looks relatively benign.
  6. It will be interesting to see if the NAM is onto something. 18z RGEM is 100-150 farther SW with the surface low, but still shows upper 50s dews reaching the IN/MI border. Caveat: low level winds more veered to SW/SSW. The appearance of a notable prefrontal trough will make a big difference in the tornado potential. Without it, anything beyond a gusty squall line seems unlikely. With it, a fairly unusual late February severe threat could materialize.
  7. Although I do see a threat for locally damaging winds and brief QLCS/embedded tornadoes, I don't see Friday as any significant severe event. The analogs are lackluster and very few of them show any severe reports north of the Ohio River. It's really too early in the season for much of a warm front threat with this type of setup and the signal for any prefrontal discrete storms is poor, at best. I suppose given the shear you could have some line segments with a strong/marginally severe wind threat, if storms do form ahead of the cold front. Analog guidance WRT 1+ severe report:
  8. The #1 analog as of 00z is 3/13/06 and that was a busted MDT risk for the Ohio Valley. It's actually a very good analog given the synoptic setup, wind fields and low-level moisture. 18z special ILN RAOB had a 56F dew-point, FWIW:
  9. There's not much that supports backing of low-level wind fields in the warm sector on Friday. The warm front has been fairly consistently progged to lift north through IN Friday morning and into MI by peak heating. While there may be a marginal tornado threat here, dew-points in the mid-50s won't cut it. Farther south, the guidance is unanimous in veering winds in the lowest km, yielding a largely unidirectional wind field. (00z EC included) Sure, given the magnitude of speed shear, it won't take much subtle backing to enlarge hodographs. The most likely convective mode will be linear with the potential for a few QLCS spin-ups, assuming dew-points can rise into at least the upper 50s. If moisture return is greater than currently progged with northward extent, watch the warm front, but that seems fairly unlikely given this setup and the time of year. While many analogs show some substantial severe events, most of these occurred in March and featured 60+ dews. A quick assessment of model progs also suggests the surface low occludes several hours before peak heating, further suggesting a veering wind profile with southward extent. This includes the 84hr NAM, FWIW. Terrain influences are not helpful and if anything, support a more of a SWrly low-level wind field than a Srly or SErly immediately west of the Appalachians. Thursday looks increasingly interesting SW of this sub-forum, but marginal low-level moisture and capping will most likely keep any threat limited across MO and surrounding areas.
  10. Skewed by the recent outbreak, this month has already featured the second most January tornadoes since 1950. The record is 212 in 1999 and we're already over 100 so far. (the month should end quiet though)
  11. Substantial low level shear compensated for only "modestly" backed near-surface winds as 0-1km shear was on the order of 40-50kts immediately ahead of the line of storms, supporting >300m2/s2 0-1km SRH. The HRRR did a good job at modeling the simulated radar, even as early as last night, showing "stringy" supercells, due in part to significant shear in the lowest 1-2km. The shear wasn't much higher than recent higher-end events, so I'm not sure it's valid to say there was too much shear. Multiple factors likely played a role. Sure, the CAPE/shear parameter space was great on paper, but even the HRRR didn't seem keen on widespread, intense supercells. More or less, it nailed the idea of only a few significant cells mixed. One argument for high risk is that it's easier to verify in more densely populated areas. That alone could be a defense for the outlook. I wish CIPS would bring their realtime PPF maps back to see what verification looks like.
  12. With respect to the lower Mississippi Valley region, this setup is quite similar synoptically to 1/21/99, although not nearly as unstable with appreciable moisture return stunted farther south. Nonetheless, that event produced hail to softball size and numerous tornadoes in Arkansas. Even with somewhat less impressive instability (1,500-2,500 J/kg MLCAPE vs. 2,500-3,500 J/kg), it's more than enough given the kinematics for multiple instances of very large hail and at least a few tornadoes with discrete/semi-discrete convection.
  13. Moisture pooling beneath an outflow boundary in southwestern Nebraska. Storms may have a tendency to merge/cluster relatively quickly, but look for a concentrated conditional threat down there from late afternoon into early this evening.
  14. A cluster of thunderstorms tried to organize in southwestern Iowa this afternoon, but most storms in the region today struggled to maintain organization for very long.
  15. Majestic Mammatus

    From the album Summer 2016 Thunderstorms

    Mammatus clouds become more prominent in the sky, just west of Buffalo, South Dakota. August 9th, 2016.