2024-04-25 EVENT: TX/KS/OK/NE/CO

[JamesCaruso]

Took a look at some early-morning analysis. Cap looks to stay strong in SW KS and TX PH. Not much convergence along dryline. Models seem in agreement with a dryline bulge type of feature in west central / NW KS, with moisture wrapping up around the surface low and backed winds along the warm front. However, this creates a very narrow zone of instability with the NW/SE-oriented warm front and relatively cool air to the east. I think it would be a tough decision to make at this moment (it's only 5am CDT). One possibility is around Hays KS; further north has better backed winds and convergence, but it's a more just-in-time moisture situation (60s dewpoints confined to OK and extreme SW KS right now) and the noted narrower region of instability. SW KS should have deeper moisture and a wider zone of instability, but less convergence along the dryline and a stronger cap. Perhaps there will be an outflow boundary / dryline intersection that provides the necessary convergence. Or maybe open warm sector initiation with large-scale forcing from the mid/upper-level support? I would be thinking a bit east of DDC could be a viable roll-the-dice target. If I were really chasing, I'd want to see more over the next few hours, as it's pretty early yet, and it does not seem clear-cut to me at the moment.

EDIT: When I looked at this 24 hours ago (using OZ 4/24 model runs) the GFS had the warm front and moisture progressing further north in Kansas than did the Euro. The current consensus appears closer to what the GFS was already showing earlier.

 

[Warren Faidley]

El Sneak Attacko!

 

[Dave C]

Looks like 60s dews should be overspreading up to the I-70 corridor by 0Z. RAP meosanalysis showing a minimum of 4 degrees increase in the last 3 hour dewpoint change in SW KS with 50 to 60s already in place N to S.

Ongoing convection may leave outflow in a favorable orientation to storm motion and the dryline closer to I-70 corridor according to vis sat. Currently low clouds/fog over SW KS, but also some clearing evident or likely soon at some stations.

Some convergence on RAP hourly near Scott City this AM. Mesoanalysis TOR Environment browser showing nearly all parameters already within statistical range, and will likely improve toward sig tor during heating.

It seems there will be sufficient forcing in place for cap to break across the region of best parameters by 22Z or earlier. CAMS are firing discrete from NE CO to SW KS by 21-23Z.

My target for today has not changed much since yesterday, initially Scott City vicinity or perhaps a bit more north, adjusting during stops on the drive. I fear the narrowed corridor of best parameters and breakable cap may cause a convergence of chasers as well. :/ For that reason, I may stop and hedge on the NE CO target which still looks to fire earlier than KS.

The much harder question for me is tomorrow and Sat as they will begin to consume vacation days and a lot more gas coming from CO, and less familiar terrain to me that could be closer to more metro areas and river crossings (Friday). Good luck to all who are out this sequence!

 

[JamesCaruso]

SPC has pulled back on the hatched TOR area, now limited to NW KS. My earlier Hays target seems latitudinally correct. A little too far east, but if I were actually chasing there would have been plenty of time to adjust the target.

 

[gdlewen]

Appeal to ST chasers: as we move into today's event, I would love it if people would point out OFB or other boundaries they see that can initiate convection. I frankly have a hard time "seeing them, unless they can slap me in the face: lines of cumulus, multiple wind reports clearly delineating local convergence, etc. The more subtle stuff (like a single wind report with no apparent moisture convergence, etc.) just leaves me scratching my head. Numerical analysis covers that deficiency, but only to a point.

 

[Jesse Risley]

Appeal to ST chasers: as we move into today's event, I would love it if people would point out OFB or other boundaries they see that can initiate convection. I frankly have a hard time "seeing them, unless they can slap me in the face: lines of cumulus, multiple wind reports clearly delineating local convergence, etc. The more subtle stuff (like a single wind report with no apparent moisture convergence, etc.) just leaves me scratching my head. Numerical analysis covers that deficiency, but only to a point.

Just looping vis sat I can see a few based on previous convection. I also used yellow dashed lines to delineate areas of mass divergence overlaid on vis sat. The northern boundary was laid down by ongoing convection moving ESE whereas the boundary down near DDC appears to be relatively stationary and has been there awhile, which I actually believe may be the effective surface front (without taking a closer look at surface observations by themselves). That boundary, likely the stationary front, is marking the northern advance of the deeper moisture right now. The convection further south appears to be leaving a subtle boundary but that is likely to be removed from the greater threat area that will materialize in NW KS later.

 

[Dan Robinson]

Good to see the lack of cirrus (or any cloud cover) upstream of western Kansas. It appears that we'll see at least a 100-mile wide corridor of good insolation east of the dryline. The 96-frame Goodland radar loop shows outflow boundaries slowly moving south of I-70 from overnight convection, but nothing that is surging crazily. The central/eastern KS MCS appears to be on its way out, again without a huge surge of westerly outflow so far. The caveat to that is that the ambient SE surface wind fields across KS favor pulling some of that air toward the dryline.

COD-NEXLAB : Dual-Pol Radar for GLD

Dual-Pol NEXRAD Data for provided by College of DuPage Meteorology (NEXLAB)

weather.cod.edu

 

[Warren Faidley]

As speculated, DDC is sending up a special balloon launch. Does anyone know how or where to see this sounding?

 

[Jesse Risley]

As speculated, DDC is sending up a special balloon launch. Does anyone know how or where to see this sounding?

Upper-Air page: RAL Real-Time Weather or https://www.spc.noaa.gov/exper/soundings/

 

[Mike Smith]

As speculated, DDC is sending up a special balloon launch. Does anyone know how or where to see this sounding?

COD Meteorology -- Analysis Data I've found it to be more timely/reliable than SPC's.

 

[gdlewen]

Here's the 17Z OK Mesonet data--you can make out the dryline to the W and the warm front across NE OK.

I had to add 17Z METAR to points outside the OK border to get smooth, sensible contours across the entire map area. But inside the OK border it's just the OK Mesonet data.

No boundaries are evident in this display...

 

[Greg McLaughlin]

Surface low is really starting to deepen as mid/upper jet begins to cross into the lee of the Rockies. Down to 998mb near LaJunta, CO. The warm front shows up nicely on vis satellite. Really like the insolation we are getting over western Kansas. So far, things look to be headed in the right direction.

 

[Dan Robinson]

Towering cumulus already bubbling up on the boundary south of Grainfield.

 

[Warren Faidley]

Low DP's and cap seems to be nuking things ATM. It will be interesting to see what happens in the next two hours.

Yet another potentially "insane" daytime event that busted. Us "at home" chasers can now take a deep breath. I don't remember another year in over 36 years of chasing that had so many fails. I can only **guess** some drought-related (EML) element is messing with things or forecasting is retrograding.

Postmortem time.

 

[gdlewen]

The bottom really fell out of the dryline south of KS:

 

[Jamie H]

Low DP's and cap seems to be nuking things ATM. It will be interesting to see what happens in the next two hours.

Yet another potentially "insane" daytime event that busted. Us "at home" chasers can now take a deep breath. I don't remember another year in over 36 years of chasing that had so many fails. I can only **guess** some drought-related (EML) element is messing with things or forecasting is retrograding.

Postmortem time.

EML + late trough + it seemed like the trough kinda flabbed out a bit rather than tightened as it moved Eastwards? I'm pretty inexperienced so could be well wrong!