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About Quincy

  • Birthday 02/03/1987

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    Oklahoma City, OK

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  1. Wednesday looks like a tamer version of 4/25/11. That period in late April is an example of things going almost entirely perfect for bigger April severe stretches. This time around, it looks more like run-of-the-mill stuff (at least compared to the last few months of April), if not a downright train wreck given the synoptic pattern. Tuesday looks like a borderline cap bust, although there may be a very narrow window for a tornado in the north-central/northeast OK to southeast KS vicinity early in the evening. Models have waffled a bit with convective initiation in the 00-02z time frame with a very quick linear transition. Wednesday still has issues, but could, at the very least, produce a few brief QLCS tornadoes. If shear vectors were less parallel to the surface boundary, it would probably be a central Arkansas local climo tornado event with channeling of backed low-level flow pairing with a seasonably impressive CAPE/shear overlay. Still, enlarged 0-1km hodographs and more than adequate deep layer speed shear could allow for a few short-lived supercell tornadoes. I'm not getting into details for late week just yet...
  2. Severe weather parameters (such as SCP and STP) don't take all factors into consideration. For example, on Tuesday, the SCP is seemingly very favorable for supercells in North Texas, but with warm mid-level temperatures, it's not likely that the cap will be breached in order for deep convection to materialize. As for central Arkansas on Tuesday, let's briefly analyze the 72hr forecast sounding for KHOT (Hot Springs, AR), which does show a "PDS TOR" sounding with effective STP values over 3. Notice the flow in the 2-8km layer, which is not only unidirectional, but parallel to the forecast surface boundary. This strongly suggests a forced linear line of convection. Although there is some low level hodograph enlargement (0-1km), the 1km and 6km wind vectors essentially overlap. Also not the poor 0-3km lapse rates below 6 C/km. This is not a sounding for a strong tornado and almost certainly not a sounding for discrete supercells, although QLCS-type spinups would certainly be possible.
  3. Thoughts on early in the period, as models seem to be in fairly good agreement through Wednesday: Monday - Probably no robust convection. Despite a surface low developing and moving into the OK/TX panhandle vicinity during peak heating and an EML producing steep to very steep lapse rates across the southern High Plains, inadequate low-level moisture return and large T/Td spreads through the boundary layer should offset any realistic potential and severe. Can't completely rule out a rogue cell trying to go up just ahead of the dryline, but the potential is close to zero. Tuesday - Likely the first in a series of greater threats across the region. With that said, it has its own issues too. A frontal system is progged to drop through the Plains to lower Missouri Valley during the afternoon. Models converge on the most convection firing in the southeastern KS/northeastern OK/western MO area. Despite modest instability, deep shear vectors should align largely parallel to a surface boundary, suggesting mixed/messy storm modes and clustering of convection. The EML plume outruns the front, as mid-level lapse rates become less favorable with time. Capping becomes a greater concern with southward extent. Despite a seemingly favorable CAPE/shear overlap into central/southeastern OK and adjacent North TX, warm air in the mid-levels should work to make any severe threat in this area highly conditional. Wednesday - The frontal system moves east into the Mississippi Valley region. Some severe threat may materialize from the middle MS Valley, southeastward into the Arklatex vicinity. Like Tuesday, shear vectors continue to be more or less parallel to the surface front, but guidance does suggest backing of low level wind fields in the open warm sector with modest 0-1km hodographs. The main issue is that considerable convection may fire along and just ahead of the front during the afternoon, favoring more of a squall line with time. Should any discrete convection be able to form farther east, then supercells would appear possible.
  4. 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.
  5. The lead supercell near Banty, OK as I photographed at 6:47 p.m.
  6. Tishomingo cell is about to go into a radar black hole too.
  7. Seems to be struggling a bit, both visually (I'm near Marietta) and on radar. As it moves east into an area of warmer near-surface inflow, it may better organize with time. Cu fields popping down the line into North Texas. The cap is breaking.
  8. 21z FWD sounding shows a substantial cap, but favorable wind fields for severe. Storms should have little problem initiating (next 1-2 hours) to the NW of the metroplex where surface temps have risen into the upper 80s/near 90F.
  9. The only apparent red flag I see is how the shear vectors don't produce a large angle with the composite outflow/frontal boundary. Storm mode may become clustered relatively quickly. With that said, if any discrete cell that fires in North Texas can remain at least somewhat isolated, there will be significant tornado potential. The metroplex is going to be in the crosshairs, which is a bit concerning.
  10. Plenty of very large hail events showing up in the analog soundings. I generally take these with a grain of salt, since the matches are usually loose, but there's still a pretty strong signal there.
  11. 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.
  12. The hires NAM shows a fairly messy setup with faster progression of a cold front through Oklahoma. The RGEM is much closer to the GFS and shows a surface low passing very close to OKC at 00z SAT with a warm front-like boundary draped from roughly OKC-FSM. The Euro is more of a compromise between the two "extreme" solutions and may be the most reasonable at this juncture. Before I post the 00z OKC RGEM forecast sounding, I want to make it clear that this is likely one of those setups that doesn't come into really clear focus/reasonable confidence until the morning of. So many things can adjust the mesoscale setup, including, but not limited to: early day convection, effective warm front position, any outflow boundaries, capping (or breaching of cap into N TX), speed of cold front and orientation of shear vectors WRT cold front/dryline.Modify this RGEM sounding for areas just E/SE of OKC and that spells big trouble. If the cap can be breached into North Texas (as the RGEM attempts to do), I'd almost prefer that area. That's far too conditional in an already cloudy short range convective forecast.
  13. I'm in Groom and the cloud bases were fairly high at the time of the tor warning. A ragged wall cloud is now forming in the NW direction.
  14. Watch the discrete cell forming in the eastern Texas panhandle. It's been well-modeled by the HRRR all day. Although deep layer and low-level shear are lower-end, strong instability and veering winds with height (and favorable low level wind flow out of the southeast as Jim mentioned) should favor storm organization and maintenance for at least a couple of hours.
  15. The 00z AMA sounding looked awfully weak in the 500mb layer, but mesoanalysis indicated about 30kts of h5 flow at 23z INVOF the cell. That translates to ~15 m/s, which is still unusually low for tornadogenesis. Seasonably large CAPE values (2500-3000 J/kg mixed layer) helped offset the lower-end shear.