This will be the third potential shot for winter precipitation in Memphis in the past couple of weeks, and this may perhaps be the best chance of the three. A strong Arctic front is sweeping towards the Mid-South tonight and will move into the Memphis area tomorrow morning around daybreak/rush hour. This front will cause temps to fall from near 60 overnight to the 30s by tomorrow afternoon in the city with wind shifting from strong southerly to a stiff northwest breeze Monday morning. Rain will commence late this evening, but much of the rain is expected to fall after the frontal passage, as the temps are falling.
The critical temperatures that will be monitored are in the lowest 2-3,000 feet of the atmosphere. Temps above that (up to several thousand feet) will actually remain warm, promoting rain. However, by early afternoon, those low level temps will fall below freezing. As this sub-freezing layer gets deeper, a little sleet could start to mix with the rain after 3pm. Surface temperatures will still be above freezing, but in the 30s. As the surface temperature approaches freezing around 6-8 pm, the potential for freezing rain increases.
Temps will remain around freezing all night Monday night and up until about 9am Tuesday, so any precipitation that falls could freeze on contact from 6pm Monday to 9am Tuesday. Rain amounts are not expected to be significant, but one-tenth of an inch of ice is possible by Tuesday morning in the metro area. This would be enough to coat bridges, overpasses, and other exposed surfaces. For this reason, the National Weather Service has issued a Freezing Rain Advisory for Memphis (and much of the Mid-South from I-40 north) beginning tomorrow through Tuesday morning. The MWN forecast will remain updated on a regular basis throughout the potential winter weather event. Stay tuned!