MU Weather Center@MUweather
Replying to @MUweather
(5/5) What does this mean for us? Systems like this are notorious for having a tight snowfall gradient. 50 miles can separate a coating from double-digit totals. Accumulating snow is unlikely north of the Mason-Dixon line, with the highest totals just S/E of I-95. #MdWx #vawx
20m
MU Weather Center@MUweather
Replying to @MUweather
(4/5) Lastly, snowfall is often heaviest where difluence is greatest in the mid-levels of the atmosphere. In the image below, this is indicated by the solid, black lines (geopotential height contours) spreading apart from one another in the outlined area.
21m
MU Weather Center@MUweather
Replying to @MUweather
(3/5) This one's a bit technical, but the highest snowfall totals and best rates usually occur along and just north of the strongest mid-level frontogenesis/warm air advection (two more indicators of rising motion and precip). This is often where the "deformation band" sets up.
21m
MU Weather Center@MUweather
Replying to @MUweather
(2/5) In the sounding just southeast of the I-95 corridor, the dry layer isn't present, meaning that snow's actually reaching the ground. Now, in the sounding below, strong upward motion co-located with the Dendritic Growth Zone (DGZ) is a great indicator of high snowfall rates..
21m
MU Weather Center@MUweather
(1/5) Here's why it can be very misleading to look only at snowfall/precipitation output from models. A dry layer of air in the mid- and low-levels on the sounding near the Mason-Dixon line means that snowfall likely won't reach the ground (virga) despite the model suggesting it.