Update on First Flakes Today Night and Sunday Early AM

The midnight models yesterday trended towards more parts of our region getting flurries/snow showers. The best chance of snow is late tonight and very early on Sunday morning. The more inland and north you are, the better chance you have of seeing snow. The mountains will be seeing a couple of inches of snow from this system. As for us, the snow chances go down as far south as northern DC. When the snow falls, it will be above freezing in most of the region. Sunday's highs will be in the mid-upper 40s which is generally too warm for snow; hence the main time for snow being very early Sunday AM. Mixing is likely in non-mountainous areas; especially when temps rise; and especially for areas that remain above freezing during the whole event.

HRRR:

The HRRR shows light snow for many parts of the region(any area that is above the blue 540 line should be snow, and not rain, the rain is a model error if it shows rain for a region above the 540 line). I don't know if it will go this south, but if it does, it will definitely mix with rain. Most areas(including all of MoCo) are above freezing; and the closest I saw to freezing for Northern MoCo would be 32-33 degrees in this model run. However, it still does show parts of our region getting flurries/snow showers.

This is the NWS map for accumulating snow(not flurries that fall and don't accumulate; just stickage). With the afternoon runs coming in a little warmer, I agree with this map. Only extreme northern and western areas will see accumulating snow; and unless you are in the Applachian mountains it will be less than one inch.

Overall this won't be anything impactful unless you are located in a mountain range. North and west areas have the best chance to see flurries/snow showers; and the further south you the chance decreases. The best chance is late tonight and Sunday early morning.

First Flakes Possible on Sunday

Good evening everyone! As you might have heard already, many parts of our region saw their first wintry weather this morning. I personally got sleet/snow mixed with rain that melted instantly. It was too light to really see, but based on the way it melted, reports around me, and radar, I was able to determine the PType. The main chance for flurries around the region will be on Sunday, and maybe Tuesday(Ill go over this soon). If you look on the models, it doesn't seem anything will be hitting us, but models usually miss these type of flurry events. The trend has been for this clipper to start earlier, which means that it will be colder when the clipper starts; therefore making conditions more substantial for snow. As usual, north and west areas have the best chance to see flurries. The best chance for snow, or a mix of snow will be in the morning and evening/night. There is expected to be no accumulation with this system, as snow rates will be too light.

This is the plume for KFDK(Frederick Airport), and it shows when precipitation falls, and what time it happens. At around late Saturday night/early Sunday morning, it shows snow starting to fall, and then as the time goes on the chances of rain start to increase and eventually it gets to a point where the snow rate starts to decrease and gives into rain. Later in the day it shows rain stopping and a little(small) amount of snow at the end. (The blue at the end is for Tuesday).

 

This is the plume for KIAD(Dulles, further south), and it shows a similar thing except that the snow lasts less longer and there is more rain(also some freezing rain weirdly pops up on this). When rain chances start to increase with snow, you can expect some mixing.