James Hyde
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wxmeddler.bsky.social
James Hyde
@wxmeddler.bsky.social
Wx Nerd💨| Space🚀| Avgeek✈️. I play with weather instruments & data 🌩 Writer for USTornadoes 🌪 M.S. Emergency Management 💥 Tweets Mine. *Mostly* Harmless.
Add all these factors together, combined with the strong MCV and you get a massive Rear Inflow Jet, with exceptional sustained winds and gusts at the surface extending over 100 miles.

tl;dr:
Wake low? No, but close
Mesoscale Convective Vortex with top tier Rear Inflow Jet? Yes.
June 21, 2025 at 8:24 PM
Looking at our sounding (this time from Aberdeen), we have a crap ton of all 3.

1. High dew-points, to nearly 700mb. With a mean liquid ratio of 16.3 g/kg (!!)
2. A boatload of CAPE (5000 j/kg) with exceptional mid-level lapse rates.
3. RH in the mid/upper regions below 30%
June 21, 2025 at 8:24 PM
What drives an RIJ is latent heat release. Evaporation of water. That evaporation drives descending winds from aloft to the surface. So what do we need to turbocharge our RIJ potential?
1. Water
2. A way for water to get up there (ie. CAPE).
3. A way to evaporate it quickly.
June 21, 2025 at 8:24 PM
Okay, so let's look at the Bulk Shear from BIS 00z Balloon last night and holy sh*t we've got westerly 100kts at 250mb and 25kts easterlies at 850mb. That's 125 kts of relevant bulk shear. This RIJ development could be MASSIVE. But an RIJ takes more than just shear.
June 21, 2025 at 8:24 PM
MCV's aren't uncommon but what really kicked it into overdrive was a very strong Rear Inflow Jet (RIJ). In particular a descending RIJ. Decending RIJ's are more prevalent in high storm relative shear environments. You can effectively simplify this as Surface to some high altitude
June 21, 2025 at 8:24 PM
So what did happen in ND last night? Well, it was likely a combination of two (strong) interlinked phenomena.

1st is the development of an asymmetric Mesoscale Convective System (MCS) leading to a strong Mesoscale Convective Vortex (MCV) / Bookend vortex.
(Fig b.)
June 21, 2025 at 8:24 PM
Wake low's are associated with a rear inflow jet that does not make it to the surface however induces pressure perturbations that drive a low pressure "rebound" near the surface. Air from the mesohigh near the squall line moves backward to the wake low. Usually Easterly winds.
June 21, 2025 at 8:24 PM
Wake low's are technically associated with winds from the front of the squall line to the back. They are most commonly associated with strong easterly winds (in a westward moving MCS) behind the storm, and are prevalent in stable environments (ie. Elevated Convection).
June 21, 2025 at 8:24 PM
I've personally seen everything from cottonwood seeds, to sleet / graupel, dust (obviously), heavy smoke, cause this phenomenon. Poor onboard instrument quality control / error detection is really ruining the wind climatology of locations with sonic anemometers.
May 18, 2024 at 2:15 AM
As part of my 2017 Masters Thesis when I surveyed NWA meteorologists about hurricane forecasting. I asked about the cone's fixed size (see attached image):
43.5% Yes, it's fixed size no matter the storm
43.9% No, it changes
12.5% Not sure
N was 255.
April 10, 2024 at 2:44 PM