Beware the ‘Flash Freeze': single-digit temps, wind chill -5 to -20
Temperatures are plummeting, the wind is kicking up... Yes, ladies and gentlemen, it's time for an ol' fashioned New Jersey arctic blast!
This is the final phase of our now-departing winter storm. And it's probably the most significant, because it's going to affect every county, town, and resident of the great Garden State.
There are certain words and phrases that I don't use in my forecasts unless I really mean it. One of those is "dangerous". I have no hesitation in calling this downright dangerous cold.
A Wind Chill Advisory has been issued for almost all of New Jersey, in effect from 11 p.m. Sunday through 1 p.m. Monday.
As of this writing (1 p.m.), the rain is gone and temperatures are already starting to drop. A strong northwest wind will be with us through Sunday afternoon and evening, sustained at 15 to 25 mph with gusts to 40 mph. This wind will drag arctic air into the Garden State.
However, to an extent, the wind is our friend Sunday afternoon. The increasing sunshine too. You see, Mr. Sun and Mr. Wind are excellent evaporators, turning all those rain puddles and wet spots into water vapor and sending it into the atmosphere. This drying trend is a very important element as the frigid temperatures approach.
That's because of the ominously-named Flash Freeze. Once temperatures fall below the freezing mark, any wet surface will freeze to solid ice. Period, full stop. With the kind of cold we're expected, standard road salt is completely ineffective. (The chemical snow/ice melt stuff you can buy at your favorite home improvement store is an exception.)
So how cold is it going to get? The HRRR model says -1 (North) to 5 (South) degrees. The NAM says 0 to 7 degrees. The GFS says 3 to 8 degrees. I say... The details don't matter! Widespread single-digit temperatures will overtake the Garden State by Monday morning.
Of course, that doesn't tell the whole story. That ferocious wind will die down slightly, but I'm still seeing gusts in the 20 to 30 mph range for early Monday. Let's do the math... Best-case scenario: 8 degrees at 20 mph yields a wind chill ("feels like" temperature) of -11 degrees. Worst-case: -1 degrees at 30 mph gives us a wind chill of -27. Ouch!
That kind of biting cold wind is not only painful, it's potentially dangerous. You see, the wind chill was invented as an indicator of the human health impacts of very cold weather. When it dives below zero, it's a warning that frostbite can occur within just a half-hour.
The bottom line here is that the first step out the front door Monday morning is going to be a doozy! You need to bundle up any exposed skin — layered clothing, warm socks, heavy coat, winter hat, gloves, and scarf. And watch your step, due to scattered ice from the flash freeze.
High temperatures on Monday will only reach about 20 degrees. Tuesday won't be much better, with a high in the lower 30s. Temperatures will moderate on Wednesday, potentially into the 50s. But that's only because our next storm system will carry along warmer air with it.
That next storm system from Wednesday-Thursday still looks like mostly rain, although I can't rule out 1.) a quick changeover to snow on the backside, and/or 2.) a track shift that puts us under the influence of colder air and therefore more wintry weather. I'm not sweating this one, just something we have to watch.
There's no sign that this train of storm systems is going to slow down, either. (Not until at least the beginning of February.) A snow shower will be possible late Friday. The next storm system with accumulating snow potential is showing up in the next Sunday to Monday time frame.
Stay warm out there!