Details on winter weather in the Memphis metro Sunday/Sunday night

It looks like the Bluff City may finally get a shot at some winter weather after a month of cold temperatures but little winter precip other than flurries! The time frame of interest (or "concern") for most will be after dark Sunday evening. This blog post will focus primarily on the expected precip types, timing, and impacts.

Sunday:
Rain overspreads the Mid-South tonight as a cold front moves through the region. Despite still being 65 degrees as of this writing (8pm), the front will usher in temps that fall nearly 30 degrees by early Sunday morning. Most of the metro, from the I-40 corridor south into north MS, will see temperatures in the 34-48 degree range tomorrow during the day, allowing occasional rain to remain liquid.

Hi-res NAM model forecast temps through Sunday midnight for Memphis Int'l Airport. The model indicates 30s all day Sunday and 32 degrees by 7pm Sunday, when freezing rain would commence.  Changeover would occur earlier to the north of the airport.

However, a Winter Weather Advisory has already been issued for Tipton County in the metro, as well as all of northern AR and northwest TN (see map below).  These areas could see an earlier changeover as lower 30s temps infiltrate the northern Mid-South.  (I expect to see a Winter Weather Advisory issued overnight for the rest of the metro.)

Sunday evening:
By mid to late afternoon, temperatures in the I-40 corridor - including Memphis and Shelby County - will fall towards freezing and some sleet could mix in with the rain. After the Super Bowl starts (or roughly 6pm and later), the counties along I-40 will reach freezing as colder air seeps south. At that point, rain will become freezing rain with some sleet still possibly mixed in as well. The freezing rain/sleet mix will move south into north MS by mid to late evening, or likely by 10pm. Cold air aloft should change the ice over to light snow in the I-40 corridor by 9-10pm with precip tapering off after midnight as light freezing drizzle.  North MS could see a little snow but most frozen precip will be in the form of freezing rain.

Below are the probabilities of 1" of snow and 0.10" of ice as issued by the winter weather experts at the NOAA/Weather Prediction Center.  As you can see, the best chances of an inch or more of snow are north of the majority of the metro, though the graphic indicates there is a chance of up to an inch along and north of I-40.

The heaviest snow will fall to our north where temps will be near or below freezing much of Sunday according to the Weather Prediction Center. Click for larger image.

Our bigger concern will likely be ice.  There is as fairly strong chance of seeing up to 0.10" of freezing rain and sleet.  I believe that the freezing rain is more likely.  Recall that freezing rain is liquid as it falls, then freezes on contact with surfaces that are at 32 or lower, creating a glaze of ice.  It is the most treacherous form of winter weather for driving and power outages and downed branches and trees.

There is a decent chance that up to 1/10" of ice will occur in the metro according to the Weather Prediction Center. Click for larger image.

Most precipitation will end by midnight or shortly thereafter.  In the metro, I expect we'll see perhaps one-tenth of an inch of ice topped by 1/2"-1" of snow (maybe a little more in northern Tipton Co with little to no snow accumulation in north MS).

Note that there is still, just 24 hours before potential impact, some disagreement in the models as to the timing of cold air, which could push the changeover time of winter precip a little later, thereby reducing expected impacts.

Impacts:
There will likely not be enough ice to cause downed trees or power lines, however roads will become slick during the evening, starting with bridges and overpasses then secondary roads. Main thoroughfares may still decent due to warm temperatures ahead of this system. Temperatures Sunday night will fall into the 20s so there is some concern for hazardous travel for the Monday morning commute as well.  We won't know the exact effect until we see how much ice and snow actually fall, but prepare for that possibility. Temperatures Monday should climb to 40, rising above freezing by late morning which will help melt any ice and snow.  I have no idea about school status for Monday morning.  That decision will likely be made early Monday based on road conditions.

We will have updated information throughout the event on our social media feeds, as well as via our forecast and radar products on our website and mobile apps (all links below).  In addition, in the MWN mobile apps, be sure to add StormWatch+, our push notification-based weather alert system that will advise you of any warnings or advisories as soon as they are issued by the NWS.

-Erik Proseus, MWN Meteorologist

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