Snow Threat on Thursday Night - Friday?

 I have been monitoring a snow threat all week, but I didn't make a post on it earlier because it looked like just rain for us and a winter storm for New England. However... model run trends today made me reconsider my decision, as we still may see some snow out of this due to it trending south. This isn't a windshield wiper(trend south and then north again), since almost all models have been trending south since midnight. However, there still may be a last-minute north trend. This is a rain to snow event. Everyone will start as rain, in the DMV, and even in the interior Northeast. However, as a cold front starts to move in Friday, we may transition over into a mix, and then possibly snow. It depends on how fast this cold front comes in. If it comes in faster than expected, we will see more snow, however, if it comes later than expected we won't see ANY type of wintry precipitation. As with many storms these years, a small change in temperature could be the difference between some snow and just plain cold rain. Heavier precipitation gives us a higher chance of snow too due to dynamic cooling. Let's look at some models.

GFS:

The GFS shows moderate-heavy rain before eventually turning into snow. However, if it has been trending southeast, that means that the cold front will push faster southeast, meaning that it is possible that we could be heavy snow when it shows heavy rain if the cold front pushes fast enough. Even when we switch back to snow, ratios will be less than 10:1. As we transition, the precip starts to weaken out.

The GFS has been consistently trending southeast since midnight runs today, and shows around an inch of snow for most of MoCo. The highest totals are still in New England. However, it has been trending for a weaker storm in those areas that are in the bullseye, but for those areas, 3-6 inches isn't bad.

NAM(12km):

The NAM shows us having moderate-heavy rain before switching over into snow. It gives us 4-7 hours of snow, but for the most part, the snow ratio will be below 10:1, meaning less snow. In my opinion, it's fixed itself from the 12z run because that was stupid. 6-8 inches in Ocean City won't be happening. According to snowfall maps, it has been trending north, then south, then north, and then south. It has been consistently showing a stronger storm, showing more and more snow for areas in the bullseye.

The NAM shows a coating to 1.5 inches of snow, with the most snow in northern areas. However, do you see that isolated purple spot in western Washington and eastern Allegany counties? That is pretty close to us. The HIGHEST totals are in New England, as expected, but if we trend southeast again, that isolated heavy snow spot could go right to MoCo! Something to watch.

Euro:

Euro shows as starting as rain, as other models do. However, they don't show any snow in this forecast. This could be because the next precip picture is 6 hours after the previous one. If I had a one-hour timestamp map, I think it would at least show some flakes. It has trended a bit southeast for us, but it also trended north with the bullseye, as you will see by the 10:1 snowfall map below.

The European shows no accumulating snow for most of MoCo(except a coating in southern MoCo that borders DC). However, it shows 1-3 inches for the Delmarva/Eastern Shore area?? This is a 10:1 ratio, and ratios will likely be lower than 10:1, so there will be less snow.

Right now, it is too early to make a snow forecast, since we are just possibly back in the snow game. If I had to guess right now though(not a forecast), a coating to 1 inch of snow, with some isolated areas in Northern MoCo getting a bit more(up to 2 inches max).  The more NW you are with this storm, the likelier you will see snow or just wintry precipitation in general. I will make an update tomorrow.