Youngstown is gearing up for its strongest winter storm since at least 2022.

The Valley has fallen victim to several uneventful winters. Whether that means the seasons were mild or snow-starved, it’s been a while since the city has had a true winter season.

It’s been great for winter lovers so far. We’ve had our snow and cold dealt to us in multiple rounds. However, the biggest and most impactful storm is about to arrive.

A cross-country storm has been making headlines since the start of the week as a widespread multi-threat system. Record cold, widespread ice, and historical snow are all on the table, with the system spawning winter storm watches from Arizona to Maine. While winter is no stranger to this behavior, it’s the most volatile season; storms like this are rarely seen and can have significant day-to-day impacts for millions of people across the country. How did we get this beast in the first place?

When assessing the atmosphere for clues, it’s best to take a top-down approach, investigating starting high in the sky. There’s a variable we don’t mention too much in our televised forecasts called relative vorticity, the measure of local rotation or spin of an air parcel relative to the Earth's surface. Basically, this variable tells us how much air aloft spins, and is a good indicator of energy above our heads. We’ve been tracking two separate pieces of high relative vorticity recently- one above the Dakotas, and the other off the Californian coast. The motion of these specific pieces would tell us a lot about how the system itself would evolve.

 

 

If you recall, forecasts at the start of the week had Youngstown getting little, if any, accumulation of snow. That’s because models had these separate pieces stay separate, which would induce a southerly storm track. If the two pieces came together, this would mean a greater area of spin, a larger system, and a more northerly track. 

 

 

That is exactly what happened. Model data now indicates these two separate blobs of positive vorticity will congeal and combine over our area by Sunday night, allowing our region to suddenly get in the hotspot of snow.

Departing the upper levels, the surface is also giving us a big clue as to what’s to come. The arctic-like air we’ve been feeling and will feel through the weekend is fueled by an unseasonably strong high-pressure system currently over the Dakotas. Down south, a weak low-pressure system has formed along the Gulf Coast.  Along with fronts, the low-pressure system is bringing up warmth and moisture high up. Southerly winds are advecting, or conveying, along moisture that will cause precipitation far North of the low-pressure system.

 

 

It doesn’t look like much on the surface, but knowing how both high and low pressure operate will spark the mess that much of the country will see.

Remember: High-pressure features sinking air, and low-pressure contains rising air. For areas right near each center, cold air and warm air will persist throughout the entire atmosphere. Things become tricky as you approach the middle.

 

 

Cold air from high pressure will sink close to the ground, causing bitterly cold conditions for all. However, as the air from low pressure rises and settles, the air above your head may actually be warmer than the surface. Scientifically, we call this a temperature inversion, but in situations like this, we simply call it a warm nose. 

 

 

Warm noses tend to be most prominent between 1,000 and 3,000 feet, sometimes with temperatures “bulging” above freezing, even as both the air at the surface and way aloft are below freezing. If strong enough, this thin layer can partially melt falling snowflakes into a ball of rain and slush. However, as the drop re-encounters cold air, it freezes back. The larger drop cannot freeze back into a snowflake, so it hardens into a ball of ice known as sleet. Sleet is most common to fall when surface temperatures are between 20°F and 30°F.

 

 

Freezing rain forms under this same process. However, warm noses in these cases need to be just a bit stronger, both in depth and temperature. Just before reaching the surface, though, the liquid re-encounters cold air, but it does not have enough time to re-freeze into ice. As a result, plain rain falls and immediately freezes upon contacting cold surfaces.

A warm nose will be a thing for all of us, but only locations with a warm nose above 32°F will receive mixed precipitation. Devastating ice is expected in southern states like Louisiana, Mississippi, Tennessee, and Virginia. Sleet will extend further north for those where the warm nose isn’t as prominent, potentially reaching as far north as New York and Pittsburgh. Places like Youngstown, whose warm nose will likely not get above 32°F for the entire event, will remain as snow from start to finish.

 

 

Scenarios that involve warm noses are one way that makes winter weather forecasting extremely complicated. Just a few degrees is enough to separate a heavy, wet snow from devastating freezing rain. It is for this reason that the storm is causing widespread panic across the southern tier of the country.

For specific forecast updates and accumulation expectations ahead of the storm, visit the Weather Section of the WFMJ Website, download the Storm Tracker 21 app, or watch our newscasts for constantly evolving data.