Weather Weenie @hour384

Meme idea in the Distracted Boyfriend format: "me" turning away from "a perfect 68° sunny weekend" toward "10mb zonal wind forecast at hour 360," captioned "Sorry babe, the stratosphere is doing something."

18z GFS happy hour rules: 1. Never screenshot the clown map 2. Screenshot the clown map 3. Post the clown map 4. Delete the clown map at 00z 5. Repeat.

Well, this is quite a remarkable forecast to see at this time of the year! The ECMWF 12z run (1st chart, left) shows a wind reversal at 10 hPa (see the negative value in the bottom-left corner). As a result, the sPV becomes significantly displaced from the North Pole and splits into two distinct cores. This pattern is usually associated with a major sudden stratospheric warming (SSW). If the forecast holds and the resulting anomalies propagate downward into the troposphere, they could disrupt the usual circulation patterns, favouring a more meridional flow and increasing the potential for colder air to move southwards into Europe. But how likely is this scenario to materialise? For now, confidence is very low. This is a forecast roughly two weeks ahead, and ECM is currently showing a much more extreme evolution than the other models. We'll need to see whether future updates support the same scenario. By comparison, GFS (2nd chart) also shows a weakening of the sPV, but not nearly to the same extent. The vortex is displaced towards Greenland, while two strato anticyclones over the opposite side of the polar cap push against it. Very interesting times right now: cyclones down here, and unusual outlooks up there!

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@SteveOweathaguy Every year we say we won't fall for it. Every year it's 18z and we're refreshing.

@judah47 GFS picking a Canadian Warming and the Euro going full split is the most on-brand model disagreement possible. Counting down to Monday's blog.

Forecasting snow is hard. Forecasting that someone will post a 2005 blizzard reanalysis the second the weather gets boring is easy. Verified 100% of the time.

@stateofcrimmi Polar vortex dressing up as a stretched rubber band for Halloween. Trick or treat, Minnesota.

@LopWx Every El Niño winter thread is 50% science, 50% coping. Here for both.

@AgrimUPWX Somewhere a clown map is being screenshotted as we speak.

Every October: "this winter could be historic." Every March: "the pattern was there, it just didn't produce." I'll be emotionally all-in again regardless.

Late October: seven suns on the 7-day while the stratosphere falls apart 20 miles up. The duality of a snow weenie's life.

@LaviCozma Have you never just yelled at a wall before?

@a_dose_of_wx There is still time to repent

@BostonWxConsult

Reminder to self: a weak polar vortex doesn't mean snow in my yard next week. Reminder to self: you are going to ignore this reminder.

Honest question for the weenies: what's the furthest out you've ever let yourself believe a snow map? Day 5? Day 10? Hour 384 like a true degenerate?

Idk who needs to hear this, but normally the same pattern that forces a disruption to the stratosphere polar vortex in the cold season (Scandinavian blocking, pacific jet extension, etc.) often coincides with anomalous warmth across the east-central US.

The GFS showing three separate polar vortices at the end of the run is the most GFS thing that's happened all October. Never change. (Please change.)

@thetoreadorbear You couldn't make it past your second 18z.

@Vincent_Ledvina This.