FINAL FORECAST FOR MONDAY-TUESDAY STORM

The NWS has issued a winter weather advisory for the entire county and down to Prince George's county,  expecting up to 2 inches of snow and up to 0.1 inches of ice. But, I think we could see more than 2 inches, and maybe even 3-4 inches in some areas of our counties(mainly northern areas). The models have been consistently trending colder for our area and also giving more precipitation, so snow total amounts have increased. The storm will arrive at 5-7 PM, and the main bulk of our wintry precipitation would be between 8:30 - 12 AM, including snow and sleet. During this time period, expect moderate-heavy snowfall rates. When the snow starts to fall, it will be dark, meaning that temperatures will be at least a few degrees cooler, plus no sun angle to melt the snow. This helps our chances of starting as snow/sleet. Surface temperatures are more than cold enough to support ice and snow on it. It is going to be very messy, to say the very least. If you are traveling north and west, please be even more careful, especially near the warning areas, because they are expecting enough ice to damage power lines and make tree limbs fall. Even if you are traveling south and east, still stay careful because although conditions won't be as bad as compared to north and west, they can still be bad enough to cause trouble. The winter precipitation is supposed to continue through Tuesday morning, but after 8 AM, all of the precipitation will clear up. There might be some scattered freezing rain/showers though. The heavier the precipitation is, the more likely that precipitation will be wintry, and the lighter, the more likely it is rain. And I must emphasize, just because you see one type of precipitation now doesn't mean you will see it for a longer period of time. Precipitation types will be constantly changing, so be vary of that. 

The NWS shows 0.1-0.25 inches of ice for a little more than half of our county, while the rest of the county is in the 0.01-0.1 inches of ice area, mainly in the southern and surprisingly more western areas. 0.25 inches of ice is enough to cause a winter storm warning.

The NWS shows 2-3 inches of snow for most of our county, while scattered areas of the county are in the 1-2 inches of snow area. They also predict the precipitation(just in general) to arrive at 5-7 PM.

This map from the Capital Weather Gang shows 1-3 inches of snow for almost the whole county, with a very small portion of it in the coating to 2 inches of snow area.

NBC 4 shows 1-2 inches of snow for the southern quarter of MoCo and 2-4 inches for the rest of the county.

FOX 5 shows 1-2 inches for half of our county, specifically the NE part, and the SW part is in the "Sleet to Freezing Rain" section, where a coating is possible, but that's about it. I couldn't find any snowfall maps for ABC 7 or WUSA 9, other than what they think. 

WUSA 9 shows a Trace-1" of snow for our area, with one super NE section of the county in the 1-3" of snow area. I don't agree with this map, because almost every other map has more of the county in the range of over an inch.

ABC 7 shows that the mix arrives around 1-5PM, and then during 5 PM Mon - 5 AM Tue, a mix/snow will occur for us and the general DC area, with rain south and east. There will be slick spots on overpasses during this time. At 5-10 AM, there will be lingering slick spots, with a mix/snow and rain south and east. They didn't say much else about the amounts, other than "A wintry mix of rain, sleet and some snow may lead to an inch or two slushy snow along with a glaze of ice." They didn't give any maps though, other than the impacts by timeline map.

In conclusion, just be careful about this storm, especially north and west of MoCo. It won't be significant, but it will be enough to cause some minor disruptions. I do think a boom is actually quite likely at this point, around 35%-55%(a boom is when there are more snow and ice than what was forecasted, and if it's more widespread). As for impacts, for school closures, I think there is a 35% chance of no school and a 40% chance of a delay(however I am not sure how that would work out). If there is no power, there is no school regardless of what the county says.