521 FXUS64 KMEG 110534 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 1134 PM CST Wed Jan 10 2018 .UPDATE... Updated for 06z TAF discussion && .DISCUSSION... A complex winter weather system expected to impact the Mid South Thursday night into Friday. First off, expect very mild and moist conditions ahead of an arctic cold front that will move through Thursday night. Light rain, drizzle, and fog will continue through Thursday across much of the region with well above average temperatures. Quickly changing weather is expected Thursday night and Friday. Temperatures will quickly fall behind a cold front Thursday night. This will result in rain changing over to freezing rain and sleet, then eventually snow through Friday. Latest guidance suggests that a more prolonged period of freezing rain will occur over the Winter Storm Watch area with lighter snow and sleet accumulations. At this time, it appears that over the Winter Storm Watch area there will be the potential for up to one quarter of an inch of ice along with 1 to 3 inches of snow and sleet. The greater snow and sleet accumulations should remain across northwest Tennessee. In addition to the winter weather potential, it appears that several hours of strong northwest winds will occur behind the frontal passage with latest guidance suggesting up to a 10 mb pressure change across a 100-150 mile distance across the front. This is likely due to the extreme temperature differences expected on either side of the frontal boundary. This should result in a period of very strong winds with a few hours behind the frontal passage with sustained winds possibly up to 30 mph, with gusts up to 50 mph possible. These type of winds could result in some downed trees and power outages. This system will be quite dynamic and additional forecast adjustments will be possible. Please continue to monitor the latest forecast for up to date details. JLH PREV DISCUSSION... /issued 334 PM CST Wed Jan 10 2018/ Winter is expected to return during the end of the work week, a Winter Storm Watch has been issued for all of West TN, the Missouri Bootheel, as well as portions of North Mississippi and East Arkansas. A dense fog advisory remains in effect across East Arkansas. The HRRR has done a good job with this hazard...and gradually shifts it into Central Arkansas later this evening. We may be able to expire the advisory a bit earlier than 6 PM when is set to expire. The latest guidance from WPC focuses more on ice accumulation from freezing rain and less on significant amounts of snow. However there is still a large amount of uncertainty with regard to both the timing...and amount of accumulation. The area of most concern is generally along the Interstate 40 Corridor Northeast of Memphis. SREF plumes from the Jackson, TN area range from zero to a high of 7 inches...with the mean right around one inch. A bit farther North, values are a bit higher...but the mean remains under two inches. However, the main threat from this system may end up being accumulating freezing rain and sleet resulting in dangerous roadways. We do not anticipate major ice accumulations capable of widespread damage at this time but once again, roadways could become treacherous. Precipitation is expected to begin as widespread rain late tonight continuing through the day tomorrow. Rainfall totals may approach one inch before a strong cold front approaches the Mississippi River late tomorrow. High temperatures tomorrow will likely climb into middle 60s...but temperatures will tumble Tomorrow night with morning lows near to below freezing everywhere across the Midsouth with the exception of portions of Northeast Mississippi. Rain will transition over to freezing rain after midnight, then likely a sleet snow mix around sunrise Friday...and transition to all snow midday Friday. Temperatures will likely remain below freezing Friday across most of the Midsouth. Any freezing or frozen precipitation will likely remain with us well into he weekend. A reinforcing cold front is expected to sweep across the area Saturday night. Sunday morning lows will likely be in the teens area wide. There is the potential for another round of Wintry weather early next week, but guidance remains very uncertain. If it materializes it appears it would be a "mostly snow" event as opposed to a Wintry mix. 30 && .AVIATION... 06z TAFs Southerly flow to start the TAF period, ceilings generally ranging from IFR to MVFR tonight, improving mostly to MVFR conditions during the day tomorrow. Other than a vicinity shower, prevailing showers should hold off until frontal passage tomorrow, occurring between 00z and 06z for all sites but KTUP. An abrupt wind shift to the northwest will occur behind the front, with gusts approaching 30 kts. Not confident enough to prevail wintry precipitation in the TAF at this time, but a changeover towards 12z will be possible. WLC && .MEG WATCHES/WARNINGS/ADVISORIES... AR...Winter Storm Watch from late Thursday night through Friday evening for Clay-Craighead-Crittenden-Cross-Greene- Mississippi-Poinsett-St. Francis. MO...Winter Storm Watch from late Thursday night through Friday evening for Dunklin-Pemiscot. MS...Winter Storm Watch from late Thursday night through Friday evening for Alcorn-Benton MS-DeSoto-Marshall-Tippah- Tishomingo. TN...Winter Storm Watch from late Thursday night through Friday evening for Benton TN-Carroll-Chester-Crockett-Decatur-Dyer- Fayette-Gibson-Hardeman-Hardin-Haywood-Henderson-Henry-Lake- Lauderdale-Madison-McNairy-Obion-Shelby-Tipton-Weakley. && $$