Major Winter Weather Event to Unfold Today into Tonight/Early Monday, with Some Impacts to Linger for Days....

 Expected impacts:

• Occasional freezing drizzle, occasional light freezing rain and/or sleet will continue at times through about 12 Noon today with ice and/or sleet accumulation of less than 0.1 inch
• Freezing rain and sleet will increase between 12 Noon and 3pm, becoming widespread by 6pm and continue through about Midnight tonight, then change to snow and continue through about 6am Monday
• Ice accumulation of around 0.1 inch is expected for most of the area with 0.1-0.2 inch possible in some spots mainly from 12 Noon today through 6pm today
• Sleet accumulation of around 0.5 inch is expected for most of the area with 0.5-1.0 inch possible in some spots mainly from 3pm today to Midnight tonight
• Snow accumulation of 2-3 inches is expected for most of the area with 4-5 inches possible in some spots mainly from Midnight tonight to 6am Monday

Discussion:

...Now through 12 Noon Today...
Freezing drizzle and occasional periods of light freezing rain and/or sleet will continue at times through about 12 Noon today. Overall, the precipitation will be very light in intensity during this period. It should also be noted, as a result, that much of the precipitation during this time period will be too light to be detected with weather radar.

Ice accumulation of less than 0.1 inch is expected for most of the area throughout the period.

...12 Noon Today through 6am Monday...
Freezing rain and sleet will increase between 12 Noon and 3pm today, becoming widespread by 6pm today and continuing through about Midnight tonight. The freezing rain and sleet may fall heavily at times this afternoon and especially this evening, resulting in rapidly deteriorating conditions across most of the area.

The wintry mix will change to snow around Midnight tonight and continue through about 6am on Monday. The snow may fall heavily at times during this time period.

Ice accumulation of around 0.1 inch is expected for most of the area with 0.1-0.2 inch possible in some spots mainly from 12 Noon to 6pm today.

Sleet accumulation of around 0.5 inch is expected for most of the area with 0.5-1.0 inch possible in some spots mainly from 3pm today to Midnight tonight.

Snow accumulation of 2-3 inches is expected for most of the area with 4-5 inches possible in some spots mainly from Midnight tonight to 6am Monday.

...Expected Impacts...
For the lighter rounds of precipitation this morning, the primary concerns will be light glazed icing on bridges, overpasses, metallic and other colder/elevated surfaces. This will create hazardous travel conditions at times, especially on the flyovers and other elevated roadways across the area (similar to what we would typically see with a "freezing drizzle" type event).

The increase in freezing rain and sleet this afternoon and evening will result in the rapid deterioration of road and other conditions across the area. Many roadways are likely to become impassable, and travel is highly discouraged. Elevated roadways will deteriorate first, followed by secondary roadways and then many primary roadways across the area.

Northerly winds of 15-25 mph with gusts of 30-35 mph may create areas of blowing snow at times, especially in more open areas with a direct exposure to a Northerly wind tonight into early on Monday morning. Additionally, what is likely to be the presence of accumulated ice/sleet followed by accumulated snow combined with the gusty winds may result in the downing of tree limbs and power lines in at least some parts of the area, which will increase the risk of power outages in the affected areas.

Temperatures will remain well below freezing following the event, bottoming out in the single digits early on Tuesday morning, and not rising above freezing (and then briefly) until after 12 Noon on Wednesday. This means that the accumulated ice/snow will remain across the area from Monday through at least Wednesday, which could further hamper efforts to restore power to areas with outages from the storm. As a result of this, we highly recommend that preparations include making sure to have an alternate heating source should your primary source fail as a result of the storm and/or the cold temperatures creating demand that some gas/electric companies cannot fully meet.

...Additional Information Concerning Next Week...
Another round of wintry precipitation is expected from late Tuesday evening through Wednesday morning. Please refer to the latest updates pertaining to that time period for additional details.