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About Quincy

  • Birthday 02/03/1987

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    Oklahoma City, OK

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  1. A long-lived supercell has lasted for more than 200 miles from southeastern Montana into South Dakota this evening. Hail was the biggest impact, as Newell, SD was hit the hardest. I was able to photograph the storm, mainly from its southwest side and here are a few of the scenes, including hail up to ~1.75 inches in diameter. Large hail-producing supercell just north of Belle Fourche, SD. Large hail in Vale, SD. Closing out the day's storm chase with a shot from Sturgis, SD of the supercell.
  2. It's definitely an odd (or at least unclear) setup. All guidance has been highly variable, from NCAR ensembles to HopWRF, HRRR, 3km NAM, etc. The trend has been for already (progged) minimal large scale forcing to be even more nebulous. Forecast soundings don't show a significant cap, yet convective temperatures appear out of reach for most of the warm sector. The final evolution may very well include a few cells trying to go up in WI, while more robust activity is delayed until after 01-02z, but as nocturnal cooling takes place, the window for severe could be quite limited. An already conditional threat becomes even more unlikely with westward extent across Iowa, despite a seemingly favorable CAPE/shear overlay. Negligible forcing will likely be a large limiting factor.
  3. Upon deeper investigation of today's threat, analogs feature quite a bit of severe events from southern MN/IA into WI. Along with about 1/3 of analogs producing one or more tornadoes in the northern IA vicinity, 7/6/14 can be identified as a close analog to the expected environment later today. General similarities can be seen in the upper levels, with fairly close matches in the sfc-3km layer, including capping, frontal placement and low level shear. That event produced numerous weak tornadoes in Iowa, along with a couple of longer-lived, destructive ones. The 00z 7/7/14 DVN sounding is very similar to forecast soundings across central IA around 00z Friday. Convective evolution looks similar to what is expected tomorrow as well. Isolated storm coverage with concerns about longevity of storms, given relatively warm 800-700mb temperatures. Even the SPC day 1 discussions from 7/6/14 sound similar to what's being said this time around. Iowa is a fickle state, but today's event could very well be a bit sneaky. Isolated storm coverage, favorable shear (speed, directional and orientation with respect to the cold front). Early day convection doesn't appear to be a big concern and even if there was any, it would probably be minimal and could locally enhance the severe threat, were outflow boundaries to be evident. While capping may delay convective initiation until after 22z, forecast soundings in the immediate prefrontal warm sector show little to no remaining MLCIN by 23-00z.
  4. It doesn't look like anything crazy. A cold front drops through from the northwest. Given rich boundary layer moisture and strong heating supporting upwards of 2000-3000 J/kg MLCAPE, veering winds with height (SW near the surface to NW at 500mb) and more than adequate deep layer shear magnitudes, large hail and damaging winds seem likely with initial discrete/semi-discrete supercells. Convective evolution with time is a bit unclear. While upscale growth into a linear system would "enhance" a damaging wind threat, most of the short range guidance seems to favor more of a broken band of storms. If this does happen, one couldn't rule out an isolated tornado threat by early evening. Still, if there is a tornado or two on a northwest flow day with large CAPE and ample shear in July in the upper Midwest, that's nothing unusual at all.
  5. A late season severe threat targets the southern Plains later today. The focus will be maximized along a composite front/outflow boundary from northwest Texas into Oklahoma. Although favorable deep layer shear (30-45kts) should juxtapose with large CAPE (3000-4000 J/kg mixed layer), relatively weak flow in the 0-2km layer should keep the main threats as large hail and damaging winds. A tornado can't be completely ruled out, given enhanced low level vorticity near the boundary. CAM guidance has been inconsistent with details of convective evolution, which is not surprising given subtle details regarding the boundary. Given the parameter space, including 7.5-8.5C/km 700-500mb lapse rates, I wouldn't be surprised to see a few intense supercells with very large hail, although the window for discrete activity may be limited given shear vectors oriented nearly parallel to the W-E oriented boundary. S to SE low-level winds should help somewhat, especially if those winds are/become a bit stronger than progged. My guess is that NW Texas/SW Oklahoma will have the greatest relative severe threat late this afternoon, where remnant outflow intersects with a wave of low pressure. Obs in SW Oklahoma at 10z include temperatures already in the mid-80s with low to mid-70s dew-points and SE winds near the surface. Discrete/semi-discrete convection should also initiate in an upslope regime across northeastern New Mexico, but less favorable boundary layer moisture should limit the threat there. There would appear to be potential for one or forward propagating convective systems later tonight as well, perhaps one from SE OK into AR and another farther west, pending convective evolution.
  6. Just quick driving through the edge of Pleasantville, I saw trees sawed in half like toothpicks and that was apparently just on the northern fringe of the damage path.
  7. Synoptically, tomorrow is somewhat similar to today. There should also be an early day MCS that may eave outflow boundaries and keep LCLs down a bit. The two red flags that I see are a weaker low-level jet and convective overturning, as the morning MCS may fragment the boundary layer wind fields. Watch the southern flank of the aforementioned MCS (lower Missouri Valley) and the NE/SD border region, assuming the latter has adequate airmass recovery and wind fields aren't too disjointed.
  8. A lot of things came together really, including low LCLs and rich boundary layer moisture (lower 70s dews pooled in southwestern Iowa) which helped allow the tornado threat to get going rather early in storm development. Whenever you have low LCLs and substantial low level shear, it won't take much for storms to rotate and become tornadic. Just noting climo, the mean MLCAPE for tornado events in southern Iowa is generally in the 1500-2000 J/kg range and tonight was at or above that range. Going back to LCLs, I didn't see any conclusive tornadoes, but saw plenty of very low wall clouds and funnels, even with cells that looked junky on radar. Rolling hills blocked my view of Arbor Hill, but the wall cloud could have easily been mistaken for a large wedge. The cloud base had to have been AOB 500m, but by the time I got there, the funnel was lifting. Another consideration is that storms fired along an apparent residual outflow boundary, ahead of the cold front. That alone was a key difference between a brief supercell tornado threat and a more widespread, longer-lived tornado event, like we saw. From a chasing standpoint, it was certainly not easy. A lone cell fired north of DSM by mid-afternoon and that decoyed some chasers north. Those who jumped on the early southern echo near Nebraska City probably had the catch of the day. I was slow to bite and if it wasn't for hills blocking view, I'd probably have had better footage of the tornadic storms up near I-80.
  9. The environment over southern Iowa is actually quite favorable for tornadoes, if only shear vectors were more perpendicular to the front/mesoscale boundaries. Storms may tend to cluster fairly quickly. Sharper backing of near-surface winds would also be more supportive. Already seeing >2000 J/kg MLCAPE with >20kts 0-1km shear, enlarged 0-3km hodographs, low LCLs (<1000m) and dew-points in the upper 60s to lower 70s around the area. The most likely scenario looks to feature initial supercells/supercell clusters, quickly transitioning to more of a linear convective system with embedded supercell structures. This could still yield a few tornadoes, but if discrete modes were to be realized for a longer time, then maybe you could argue greater tornado probabilities. We'll see. Any scenario from a convective mess to multiple tornadoes (even possibly a strong tornado, given 0-2km flow/shear) could unfold. I'd lean more pessimistic given climatology and the minor issues mentioned above.
  10. A great example about SCP and STP uselessness is evident this evening. 01z mesoanalysis shows values of >40 and >7 respectively in parts of the eastern half of Nebraska, yet all guidance and near term trends remain very consistent in showing a continued messy storm mode with any tornado threat being brief, very limited and constrained to QLCS processes. (Not only are tornadoes not particularly likely, but the threat of any significant tornado is close to zero) There is an array of issues with the setup tonight, including, but not limited to considerable SB/ML CINH, weak upper level flow (~20kts at 500mb), storm mode, etc. For tomorrow, there are many issues as well. Just quickly looking at recent runs of the HRRR, SW near-surface flow across most of central/eastern Iowa at 18z is not very encouraging for supercell tornado potential. Yes, the strength of the low-level jet (unseasonably strong climatologically for midday) helps offset the lack of substantially backed flow somewhat, but despite modest 0-1km SRH, hodograph size is still relatively small in forecast soundings. Outflow boundaries and an effective warm front will be important considerations, of which will be modulated by convective systems/elements tonight. An "enhanced" wind threat seems probable in almost any scenario, but unless short term trends start improving soon, I wouldn't get too excited about a tornado threat just yet. It seems likely to be another Iowa "letdown" given current expectations.
  11. Witnessed some deep hail with that same cell near Dalhart. 4-6"+ covering US-54, causing some apparent stranded vehicles. Not the best photo, but:
  12. Should convection both initiate in eastern Kansas AND remain at least semi-discrete over the next 1-3 hours, there would be the potential for very large hail. While low level shear is not particularly impressive, substantial low level vorticity and enhanced 0-3km CAPE could locally elevate a tornado threat as well. Overall extreme instability and >40 knots of deep layer shear will certainly favor explosive, rotating updrafts, once remaining CINH is overcome.
  13. Today looks to be the last in a string of elevated severe weather potential days across the central states. It's only fitting that convective evolution looks to be complex once again. The overnight significant MCS/possible derecho has had a large impact on the environment across much of Missouri. Rich, boundary layer moisture remains across eastern Kansas, while a reduction in theta-e is noted over Missouri with cooler surface dew-points, smaller CAPE profiles and fragmented wind fields as well. While airmass recovery is still expected, even in the wake of the MCS, the convective forecast remains a bit complicated. A sizable area of extreme instability is likely to reside by early afternoon across eastern Kansas (>4000 J/kg CAPEs), however, a layer of warmer temperatures around 850-800mb is noted in forecast soundings. This may result in capping concerns here, leading to isolated/sporadic storm development. Furthermore, somewhat weaker winds aloft (30-40 knots at 500mb) combined with some capping leave big question marks with the longevity and intensity of any updrafts between roughly US-77 and the MO border in Kansas. One other positive note is that low-level winds are expected to remain southerly in the region, promoting favorably turning winds with height. To the east, convective initiation seems likely by early to mid afternoon across northern Missouri/southeastern Iowa. The issue here is that winds near the surface should be more veered (southwesterly) and the deep layer wind profiles favor mixed storm modes, quickly transitioning to MCS potential into eastern Missouri/Illinois. The 3km NAM is probably too bullish in convective coverage, as it shows an extensive area of convection from western Kansas to northern Illinois by early evening. The HRRR eventually shows similar evolution, but not until later in the evening (convection is somewhat more isolated in that corridor in the 23-02z time frame). The 12z NSSL is somewhere between, but most guidance favors the MCS (possibly significant) scenario over the Missouri/Illinois vicinity. As far as chasing goes, I'm favoring eastern Kansas for more discrete storm modes, greater instability and more favorable low level moisture/backed wind fields. Deep layer shear vectors form roughly 45 degree angles with a dropping cold front, so that combined with modest capping lead me to believe we won't see rapid MCS/linear consolidation in Kansas late this afternoon.
  14. No, I chased the tail end supercells out by York and stayed back for some mammatus and lightning photography. Time to rest up and get ready for a potentially similar setup on Saturday, albeit a bit farther southeast.
  15. Just had a very difficult time getting from Lincoln, NE to Bellevue. Multiple tractor trailers blown over on I-80 and it was difficult to go more than a mile or two on any non-interstate roadways without encountering downed trees/power lines. So many detours. Widespread wind damage is apparent. We may have a derecho by the time all is said and done. The KC metro area is about to get rocked by the system too.