Flash Freeze: A Little Snow Could Be An Evening Problem

The light snow on the way Tuesday afternoon and evening will be a light event. It may even start with rain showers earlier in the afternoon.  This was never slated to be much. This type of system historically has enough moisture for a dusting to an inch or so at most. That’s if all would stick.  But in this El Nino winter so far, anything is something. My purpose now is to point out that this ‘little thing’, could be exaggerated simply by the timing and the temperatures. Basically the cold air will race in right around sunset. So even if there is a mix or just wet roads, there is the chance of a flash freeze during the evening.

UPDATE: See the latest timeline and Wind Advisory info in this report

Snow: Yes, I believe there will be a burst of snow or lingering snow showers for a few hours. This map from the GFS is a broad brush of what should fall, but also notice the expected freezing line at 7 PM.  Timing the cold air with the precipitation is the issue. But the colder air aloft can bring snowfall, while the surface temperatures are still above freezing.

Snow burst and timing:

This is the vorticity or spin/energy aloft I’ve been showing for a few days. It is my favorite product with this little systems as I track the fort max through central Maryland. I’ve highlighted that here, as it tracks through Virginia, to the south of Baltimore. That is what will help carry the moisture over the mountains when it would normally dry out. This track usually lead to the max potential for central Maryland.

This timing at 7 PM is when the bulk of the energy and snow showers are expected. However our peak time for ‘stuff to fall’ will be between 4 PM and around midnight. This time frame is earlier than when I first showed this last week. If you remember, I pointed out that most medium forecasts are subject to a 12 hour adjustment. So instead of a Wednesday morning ‘thing’, this is a Tuesday evening event. It will be long gone by Wednesday morning.

Stickage?

At best, a dusting to an inch on the grass… maybe a coating on the roads in the typical west and north of the Baltimore Beltway zones.

City, Bay, Southern Maryland, and Eastern Shore: Expect some rain, then mix, then snow into the evening. A dusting on the grass or car tops… but the wet roads with rapid drop in temps will be the other issue described below.

Flash Freeze?

How can it snow when the high will be in the 40s?  This is where it gets interesting. The temperature. Spending most of today below freezing, and the cold air tonight will help chill the roads. But Baltimore is expected to reach the lower 40s Tuesday afternoon.  Even if the showers were not a mix but all snow from colder clouds, it would melt. Yes- Wet roads.  But check out this slider showing the rapid drop in temperatures. At 5 PM Westminster and York should drop below freezing. Baltimore City reaches freezing by 8 PM. Sometimes a wet winter event would be followed by enough wind to dry the roads before the freezing air arrives.  This timing along with lingering snow showers may allow the freezing air to arrive and lead to some quick freezing.

Temperature Slider –>