It’s an “interesting” forecast tonight and tomorrow…a word you never want a meteorologist to use.
Most of today will remain dry, but with thickening clouds and cool temperatures. This afternoon’s high temperatures will be about 10°-12° below-average:
Those clouds will try to produce some showers, but most of the moisture will evaporate as it falls. The HRRR model’s radar simulation from 9:00am through 6:00pm shows a better chance of a few light showers by early evening, mainly south of the Triangle:
More moisture heads in tonight, with cold rain becoming likely. As temperatures drop, we’ll see a window of opportunity for some light frozen precipitation (sleet changing to freezing rain) to the north of the Triangle. The HRRR model from 6:00pm through 6:00am estimates that “ice window” to be open from about midnight through 4:00am:A different forecast model, the North American Model, keeps the chance of freezing rain hanging around until just past sunrise, then cold rain takes over for the rest of the day. Here’s that model’s simulation from 6:00am tomorrow through midnight:
While those models give us a good idea of what to expect, none of them are perfect. We have to look at the range of possibilities, because just a tiny change in the temperature profile of the atmosphere will result in big changes to what we experience here at ground level. Here’s my evaluation of the “most-likely” scenario — wet roads in the Triangle despite some sleet briefly mixed in with the rain, and the best chance of some icy road conditions along the Virginia state line and west of I-85:The National Weather Service office in Raleigh is on the same page:Accordingly, the NWS has issued a Winter Weather Advisory along and west of I-85:But even in those locations, the Weather Prediction Center only estimates a 50-50 chance of any measurable amount of ice (more than one one-hundredth of an inch):
Let’s say the cold air is more stubborn, and we get more ice than anticipated. If that’s the case, here’s my evaluation of the worst-case or “maximum chaos” scenario:On the flip side, if the warm air takes over more quickly, here’s the “minimum chaos” scenario:Again, I don’t think either of those are likely, but they represent the edges of what’s possible with this kind of setup. Winter weather is tricky, to say the least.At minimum, the Wednesday morning commute will be very wet, and I’d plan on waking up a bit early to allow for a longer drive to work.
There’s more rain in the forecast Thursday, Friday and Saturday, but at this point it’s tough to zero in on which day will be the wettest — we have to get tonight and tomorrow’s rain out of the way before we can focus on the next system:Temperatures will remain warm enough for rain, and we’ll finally see a break from the rain by Sunday afternoon, which will continue into the new work week.
A short list today, since yesterday was a holiday…
- The man who started a California wildfire that forced 7,000 people to evacuate was sentenced to prison.
- Climate change is altering the odds of a megastorm in California, and the L.A. dam infrastructure is not remotely equipped to handle it.
- Climate change is pushing desperate polar bears, kangaroos, and other wildlife into human territory.
- Astronomers are still trying to figure out exactly what the ‘Oumuamua asteroid is.
- The new Air Force One arrives in 2024. Here’s what we know so far.
- Swimming and other forms of exercise releases a hormone that may protect against Alzheimer’s, according to a new study.
- A little leftover Presidents Day nerdery: a look at the presidents who didn’t just champion science, but took science into their own hands.