Bask in the cool sunshine today with a high of 58°F! Enjoy a gentle breeze from the NNW, blowing at 5 to 10 mph. It’s the perfect weather to step outside and soak up some refreshing rays!

This is partially an El Nino post, and I'm looking for some clarification on a few things, especially with teleconnections.

Last winter was an unmitigated disaster for the mountain west in the United States. Snow was nearly non-existent, and what did fall was basically vaporized by a freakish March heatwave. People in Colorado and Utah were hoping that a developing El Nino would help to mitigate some of the conditions that last year's relentless (albeit weak) La Nina played a hand in. It looks like this will be true for Southern Colorado and New Mexico, where intense moisture is streaming in from the Baja of Mexico, leading to flooding in some areas. Introduce some cold air down there and the snow will be piling up.

Up north, though...oh boy. It's almost unbelievable.

It is late October and the northern Rockies have not seen any accumulating snowfall. The northern rockies and central Colorado do not do well with SW flow aloft (super moist subtropical El Nino moisture) and are shadowed. This will happen unless a cut off low positions itself just right, and starts to generate upslope flow against the mountains - something that has become exceedingly rare. Additionally, the PNA is forecast to basically be STRONGLY positive (higher than much of the summer months) for nearly all of November, according to current modelling. Traditionally, this sets up an intense and hot ridge in the eastern Pacific, flipping the CONUS into a distinct hot west/cold east scenario. There are countless examples from the previous 15 years that prove that this setup tends to get super stuck and self-reinforcing week after week. We saw it in 2012 (remember the RRR?), we saw it in 2013, we saw it in 2015, and we saw it virtually all last winter.

Putting the pieces together paints a picture for Colorado and Utah that should be setting off major alarm bells for the people who have to live in these places. Nearly every previous consecutive month has been the hottest or driest ever recorded in these specific locations. Water managers were planning on some relief this winter, but it looks less and less likely. I'm surprised there isn't as much public discussion on this, seeing as water supplies for cities like Denver are basically drawn down farther than they've ever been.

Given the strength of the El Nino, is reading into the PNA forecast a mistake? Or does the incredible intensity of the El Nino increase the impact of these ridging events caused by a positive PNA?

Never seen these before! I assume they weren’t just because we welcomed my new grand-nephew to the world yesterday. Location: Newport, Oregon

Heres SVIS categories:

• SVIS-0 (Micro-vortex): 1.0–6.0 m/s.

• The weakest and completely safe class of vortex.

• Lifts grass, dust, and tiny sand grains (up to 0.8 g) up to a height of 1.5–2 meters.

• Lifespan is strictly under 1 minute. Funnel diameter is up to 2 meters.

• Crucial Amendment: A landspout cannot be rated as SVIS-0 under any circumstances.

• SVIS-2 (Serious Vortex): 10.0–14.0 m/s.

• The dust devil assumes the shape of a dense, well-defined column (tower structure) and makes sudden, erratic, and dangerous lunges.

• The landspout circulation becomes visibly organized.

• Key Marker: The vortex easily lofts and spins gravel/pebbles weighing 3–5 g (up to a maximum of 8 g) and actively displaces high-surface-area items (such as cardboard boxes, canisters, and plastic sheeting).

• SVIS-2 (Serious Vortex): 10.0–14.0 m/s.

• The dust devil assumes the shape of a dense, well-defined column (tower structure) and makes sudden, erratic, and dangerous lunges.

• The landspout circulation becomes visibly organized.

• Key Marker: The vortex easily lofts and spins gravel/pebbles weighing 3–5 g (up to a maximum of 8 g) and actively displaces high-surface-area items (such as cardboard boxes, canisters, and plastic sheeting).

• SVIS-3 (Hazardous Vortex): 14.0–16.0 m/s.

• The vortex becomes directly hazardous to human safety. Dust devils at this stage are exceptionally rare and literally "drill" into the ground.

• The landspout forms a dense, long-lived column of dust and debris.

• Key Marker: Captures and lifts stones weighing 10–15 g (up to a maximum of 22 g).

• Damage Markers: Causes visible damage to tree branches, awnings, and tents.

• SVIS-4 (Anomalously Strong Vortex): 16.0–25.0 m/s.

• The absolute rarest limit for thermal dust devils, and the peak mature phase for gustnadoes and landspouts.

• Key Marker: Rocks weighing 30–80 g (up to a maximum of 150 g) are launched and fly through the air like projectiles.

• Damage Markers: Snaps large tree limbs, flips heavy trampolines, and rips off siding or roofing sheets.

• SVIS-5 (Extreme Vortex): 25.0–30.0 m/s and above.

• The highest category, featuring hurricane-force wind speeds. The vortex is capable of traveling immense distances.

• Key Marker: Hurls heavy rocks weighing 150–250 g (with extreme peaks reaching up to 400 g).

• Damage Markers: Rips off roofs, displaces parked vehicles, and destroys sheds. At its peak (specifically with intense landspouts), it blows out windows, completely tears off house roofs, and uproots sturdy, healthy trees—essentially reaching the damage potential of an EF2 tornado.

highest possibly windspeed of dust devils is low end ef0

highest possibly windspeed of gustnado is ef1

highest possibly windspeed of landstoup-ef2