MoCoSnow

The possibility of winter weather has excited many snow lovers (or those hoping for a school delay) in the area, but the expected amount isn’t going to make them happy.

Light snow is expected to enter the area a little after midnight and could last for a few hours. Temperatures at that time should be slightly above freezing and could dip to a little below freezing, but the amount of snow and the warm ground should not be enough to allow for much accumulation. I would expect anywhere from flurries to a coating in grassy areas with a low “boom” possibility of a half inch (mainly on grass, with a low likelihood of that happening).

While many have been asking about possible winter weather on Wednesday, there hasn’t really been much of a threat for accumulating snow here in MoCo for this one. There is a Winter Weather Advisory as close at Frederick County from 7am until 4pm, with 1-3 inches expected in the Catoctin mountains (includes parts of northern Frederick County) and a coating to an inch for other parts of Frederick County.

Not much of anything is expected in MoCo, with a coating possible for grassy areas in the northern part of the county, but temperatures would keep the roads wet from any snow that may fall. So while there may be some flakes, it shouldn’t have any impact on MCPS and barely any on the roads.

Montgomery County has extended the Hypothermia Alert for 4:00 pm Saturday, 1/14/23 – 1:00 pm Sunday, 1/15/23. Expect wind chill to be at or below 32 degrees. Wear layers and take extra precautions if you spend significant time outdoors during that time. A Hypothermia Alert is issued for the County when forecasted temperatures, and/or wind chill, in at least part of the County fall below 32 degrees creating a hazardous situation in which hypothermia and frostbite are likely. A Cold Emergency Alert could be issued for the County when dangerously cold conditions are present, including, but not limited to, sub-zero temperatures and wind chill for which it will be dangerous to be outdoors for prolonged periods of time.

There is always particular concern for children, seniors, homeless individuals and animals during periods of extreme cold.

A wind chill advisory is in effect for all of Montgomery County from 6pm Friday until 10am Saturday. According to the National Weather Service, “very cold wind chills, as low as 10 below zero, are expected. The cold wind chills could result in hypothermia if precautions are not taken. A strong cold front will move through Friday bringing a very sharp drop in temperatures with strong southerly winds shifting to strong westerly. By Friday evening, this combination of wind and cold will result in wind chills dropping below zero with wind chills as low as 10 below expected overnight Friday night into early Saturday. Use caution while traveling outside. Wear appropriate clothing, a hat, and gloves.”

Rain is likely and a little snow is possible early Friday with a rapid freeze later in the day, but there won’t be too much precipitation. A Cold Emergency Alert has also been issued for Montgomery County for 12:00 PM Friday, December 23 – 11:59 PM Saturday, December 24. “Residents should be prepared for wind chill values to be below zero degrees. These dangerously cold temperatures and wind chills could cause frostbite on exposed skin within 30 minutes and/or hypothermia. Stay indoors if possible.” More info: https://bit.ly/2JdmQ3C

A Winter Weather Advisory has been expanded to include all of Montgomery County. The advisory remains in effect until 10am this morning in NW MoCo (Germantown, Clarksburg, Poolesville, Damascus, etc) and remains in effect in the rest of MoCo until 8am. More below, courtesy of the National Weather Service:

* WHAT…Mixed precipitation expected. Total snow and sleet accumulations of up to one inch and ice accumulations of a light glaze (NW MoCo), or a light glaze of ice from freezing rain on elevated surfaces. Sleet may coat the ground as well (C/SE MoCo)

All of MoCo is under a Winter Weather Advisory starting at 10pm Wednesday night until 1pm Thursday afternoon. The advisory starts a few hours before any wintry precipitation is expected to fall and ends a couple hours after it’s expected to changeover to just rain as a buffer in case things decide to start or end a little earlier or later than anticipated.

Per our featured photo, the National Weather Service expects things to get started in MoCo between 1am and 3am. Freezing rain is expected to fall until about 8am when we see things start to changeover to just rain. Areas like Bethesda and Silver Spring may not see much freezing rain at all, while areas north of Gaithersburg may see a tenth of an inch or more. Either way, it doesn’t take much for freezing rain to make things messy.

In the images below, courtesy of Fox 5 and NBC 4, you’ll see that icing in in the central and northern part of the county  (Gaithersburg is specifically marked both maps) is more significant than the lower part of the county. This means that the morning commute could wait her be pretty bad or not so bad, depending on your location. Last night’s pencil prediction can be seen here, with an updated pencil prediction and more details on timing and what to expect coming tonight.

The National Weather Service has upped its projected ice totals for Thursday morning in the map it released earlier this afternoon (seen above in the featured photo). A little more than 1/3 of MoCo is now projected to get .1-.25” of ice with the other 2/3 or so at .01-.1”

In the “FutureCast” seen below, courtesy of Fox 5’s Mike Thomas, the freezing rain enters our area around 1am and continues to fall until turning to rain at approximately 8/8:30am in parts of the county and for almost all of the county by 9am. This is one of those situations where areas like Bethesda and Silver Spring see mostly wet roads, while areas further north like Gaithersburg, Germantown, Clarksburg, and Damascus see more significant issues involving ice.

We are now under 48 hours away from potential winter weather on Thursday morning. As it looks now, there’s still the possibility of freezing rain on Thursday that could affect the morning commute. The image below, courtesy of ABC7’s Eileen Whelan, shows that most of MoCo could be impacted by ice in the morning with temperatures in Gaithersburg at 31° at 7am.

This seems to be the general consensus among local meteorologists, with NBC4’s Chuck Bell also sharing a hi-res forecast model (seen below) that has freezing rain still in our area at 8am.

We’re now within 60 hours of potential winter weather coming our way early Thursday morning. As it looks now, we could be in for some freezing rain early Thursday morning until about 8am or so when we would see a flip to rain from southern areas to northern areas.

If temperatures remain cold enough, early Thursday morning could be fairly slick with delays very possible for our area and even closures in areas north and west that may take longer to switch over. We’ll continue to monitor this one as it gets within 48 hours tomorrow morning and we have a better idea of where that ice/rain line will be. While it’s even possible to start with a bit of snow before changing to ice and then rain, it’s still possible for this to end up being an all-rain event.