Nice write up by Justin Berk:
“Is there a case to be made for snow next weekend?
These are just notes of what I’m watching this week…
Timing of upper level energy can be off by a day when looking a full week away.
This past Friday event initially looked like an afternoon and night thing… but it ended up mostly in the morning…. And lingering into the next day with upper level support.
My purpose here is the highlight that the modeling is NOT perfect. It’s all about timing and I subscribe to the fact this polar jet has features we are not seeing handled well on the models.
Not seeing much snow now, could change if the alignment changes…. And it may from what I saw in the early morning plots.
The chaotic atmosphere is imperfectly predicted farther out in time.
1. The big push of the Polar Vortex will arrive.
2. Temps Saturday afternoon likely to stay in the 20s to low 30s.
Tracking ENERGY in the jet stream with Vorticity 5-7 days away is imperfect. Again, the timing can be off by a a few hours or a day, and that can make or break phasing - which is needed for a storm to form.
3. Vorticity Saturday morning from the EPS, which is an ensemble blend of global models. This brings the main vort max across Maryland and then just cold.
4. Vorticity Saturday morning on the European AI model looks similar, but more active. There is more energy in the pipeline.
THEN…
5. Vorticity Sunday night brings the base of the polar jet across Maryland.
Will it snow?
6. Saturday Afternoon ECMWF has a clipper to our north, with a chance for flurries while light snow in the mountains and to our north.
The timing is off and not letting it phase.
If this ends up a little south or the timing changes, I believe there’s a chance for more to develop.
7. Sunday afternoon the ECMWF AI model brings that wave in later and spins up as it hits the coast.
8. Sunday Night the GFS is later with the energy AND closest with the attempt to phase.
Just seeing the variations next weekend show me there is a lot left to be understood.
So expect the outlook to change.
It’s NOT a promise that it will snow, but a pledge that next weekend’s weather will be cold, but the rest we don’t fully know.
Faith in the Flakes”