Arctic blast tied to polar vortex to test Texas grid again

• The cold air will first cross the U.S. border with Canada on Thursday, then will make its way to the northern Rockies and Upper Plains on Friday. Temperatures will plunge to well below zero degrees Fahrenheit in Montana, the Dakotas and Minnesota.
• Daytime highs in this region may only hit the single digits or stay well below zero in the northern Rockies and the Plains, with temperatures ranging from 30°F to 50°F below average for this time of year.
• The Arctic air mass will also slink to the west, affecting Washington and Oregon.
• By the end of the weekend, the Arctic front will cross the Texas border, knocking temperatures to well below freezing in much of the state into early next week. Daily records may fall for both cold daily highs and overnight lows.

Between the lines: According to National Weather Service forecasts, about 83% of Americans are likely to see temperatures of 32°F or below by Tuesday — including Houston, Austin and Dallas, with 32% experiencing true Arctic air at or below 10°F.

• The cold will be courtesy of the polar vortex located in the stratosphere and a related circulation in the troposphere.
• The system is an area of low pressure and frigid temperatures in the upper atmosphere near the North Pole, with swirling counterclockwise winds moving around it.
• When these winds slacken or become stretched rather than moving in a circle, it can allow cold air to escape the Arctic into the midlatitudes. That is happening in this case, according to meteorologist Judah Cohen of Verisk AER.
• Cohen's research, and that of others, has shown that perturbations in the polar vortex may be connected to rapid Arctic climate change, and this is an area of active research.

The intrigue: The Texas grid failure in 2021 was deadly, but the cold temperatures were more extreme and long-lasting compared with what most computer models are projecting for next week.

• In addition, heavy snow and ice made 2021 even more impactful; this particular cold blast may not come with as much precipitation.
• The cold blast is known throughout Texas by the Weather Channel's storm name of "Uri" (the NWS does not name winter storms).
• It featured a cascade of energy infrastructure failures.

Zoom in: The state's electric grid has changed significantly since that event occurred.

• A Texas law passed in 2021 should have resulted in a better-winterized power plant fleet, according to Joshua Rhodes, a researcher at UT Austin.
• The state has also deployed about 18 times more battery storage than it had then, according to Doug Lewin, author of the Texas Energy and Power Newsletter.

• He said the state now has 5,090 megawatts of battery storage deployed, compared with just 285 megawatts in January 2021.
• The storage will come into play during the peak hours in the early morning when winds are low, the sun isn't shining yet, and some power plants may be down, Lewin said.
• Rhodes told Axios that the wind forecast looks better for power generation during this event than in 2021.

By the numbers: During February 2021, Dallas' temperature bottomed out at minus 2°F. Computer models are currently predicting that cold of similar severity could occur with this upcoming event, but for a shorter period of time.

• In 2021, temperatures plummeted and stayed frigid for days. Specifically, at DFW airport, between Feb. 13-19, the temperature stayed at or below freezing for 139 consecutive hours.
• "Tuesday morning lows may bottom out into the 20s for south Texas and the Central Gulf Coast Monday night," the National Weather Service warned Wednesday morning.
• "These anomalous freezing temperatures will be dangerous, particularly for those without adequate heating or shelter.

What they're saying: "I do expect to see power outages, but driven by snow and ice making tree limbs fall on small distribution power lines and some cars slipping on ice and hitting power poles," Rhodes said.

• "While I am not expecting major issues at this time; if snow forecasts develop over more of the state and the average temp falls another 10 degrees, there might be some."

Yes, but: It is not yet fully known how significant this cold blast will be, with some computer models projecting temperatures to be lower than what forecasts are now calling for.