As of this evening, a storm on Sunday into early Monday looks probable,so lets break this down to what we know, and what we don’t know.
What We Know:
-Temperatures will play a large role in how this storm plays out.
-Storm will be a fairly quick moving,so any snow accumulations for the most part should be light to moderate (for areas that see snow)
-Precipitation looks to begin from SW to NE between late morning to early afternoon (subject to change).
-Precipitation will likely start out as rain for most areas, and from the highest elevations down to eventually the valley floor, rain will mix with sleet and snow and eventually change over to snow.
-With rain early changing to snow and temps rapidly dropping below freezing overnight, travel on Sunday PM into Monday AM may be icy.
-Higher elevations have the best probability of seeing snowfall over 4 inches.
-Temperatures in the wake of the storm will be very cold,lasting into the beginning of the New Year.
What still remains uncertain:
-How much cold air will bleed into the region ahead of the storm?
-How quickly will the rain/ice change over to snow?
-How much moisture will be left by the time it changes to snow?
-How heavy the precipitation will fall, this can lead to dynamic cooling, causing earlier change overs, and more accumulations?
-Final track of the storm, if the storm tracks further offshore we will likely not see the influence of warmer air driven into the region, and vice versa?
-Will the cold air ever win out in the valley locations, or do we stay rain for the majority of the storm?
In closing, there are still a good amount of details that will need to be ironed out over the next 12-24 hours. There will certainly be a lot of people watching the model runs tonight and tomorrow morning, and as the data begins to iron out some of these unanswered questions we will pass the updates along to all of you, both here and on the Facebook page. As of now, Be sure to factor the potential for winter weather on Sunday afternoon into the overnight into your plans, keeping in mind that nothing is certain at the moment.
Below is the NAM model showing the warm air in the valley locations, compared to the colder temps in the higher elevations, this model certainly supports the idea of this being purely an elevation storm.