Scientific Forecaster Discussion
000 FXUS64 KMEG 220220 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 920 PM CDT Wed Mar 21 2018 .UPDATE... No updates are planned at this time. && .DISCUSSION... High pressure will continue to settle over the Mid South this evening and will provide favorable conditions for radiational cooling later tonight. This should support another frost/freeze situations across portions of the area by morning. Frost and freeze headlines remain in place. No updates are planned for this evening as the forecast looks in good shape. JLH && .PREV DISCUSSION... /issued 250 PM CDT Wed Mar 21 2018/ Early afternoon temperatures are currently in the upper 40s to middle 50s and will trend warmer over the next few days. We will see another chance of frost and even freezing temperatures tonight, but it should be the last for a while. The coldest portions of the midsouth, near the Tennessee River may dip into the upper 20s briefly with much of the remainder of the West Tennessee near or slightly below freezing. The a large portion of the remainder of the Midsouth could see frost, but should remain above freezing. Morning lows should be in the 33 to 36 degree range. Near Tunica and South into the Delta morning lows should be above freezing. Frost can damage any unprotected sensitive vegetation and freezing temperatures may kill any unprotected vegetation. Morning lows Friday should be well above freezing mainly in the low to middle 40s. Highs Friday are expected to warm into the middle 60s to low 70s. A ridge will build over the Plains over the next couple days resulting in strong Northwest flow by Friday. At the surface south winds will return to the Midsouth, initially West of the Mississippi River then gradually shifting East with time. This will pump deep moisture back across the area increasing the chance for rain and Thunderstorms. Late Friday into early Saturday a weakening surface low will track out of the Central Plains across Missouri. A warm front will be oriented across Kentucky into Missouri with a cold front trailing the surface low stretching down into East Texas. Guidance still has the bulk of the precipitation/thunderstorms to our North along the warm front with minimal activity along and ahead of the cold front. WPC has lowered rainfall accumulation over the weekend drastically, from near 2 inches in the Missouri Bootheel down to only a half of an inch and very little accumulation in North Mississippi. Confidence remains low regarding the overall weather pattern over the weekend into early next week. However, it does look more likely that the heaviest rainfall will be well to our North. SPC is not advertising the threat of severe storms in their extended products and WPC does not highlight any of the Midsouth for excessive rainfall. A cold front should move across the Midsouth early Sunday. Slightly cooler, but near normal conditions are expected Sunday into early next week. There may be a few showers around but it does not like there will be any organized threat of strong or severe storms. High temperatures will rebound into the upper 60s to mid 70s Monday into Tuesday. 30 && .AVIATION... 00Z TAFs VFR conds will persist over the next 24 hours. Northerly winds will become nearly calm overnight as surface high pressure settles in. Winds will be variable and less than 6 kts tomorrow afternoon before eventually shifting to the south near the end of the period. AC3 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...Frost Advisory from 3 AM to 9 AM CDT Thursday for Clay-Craighead- Crittenden-Cross-Greene-Lawrence-Mississippi-Poinsett- Randolph. MO...Frost Advisory from 3 AM to 9 AM CDT Thursday for Dunklin- Pemiscot. MS...Frost Advisory from 3 AM to 9 AM CDT Thursday for Calhoun- Chickasaw-DeSoto-Itawamba-Lafayette-Lee MS-Marshall-Monroe- Panola-Pontotoc-Prentiss-Tallahatchie-Tate-Union-Yalobusha. Freeze Warning from 3 AM to 9 AM CDT Thursday for Alcorn-Benton MS-Tippah-Tishomingo. TN...Frost Advisory from 3 AM to 9 AM CDT Thursday for Shelby. Freeze Warning from 3 AM to 9 AM CDT Thursday for Benton TN- Carroll-Chester-Crockett-Decatur-Dyer-Fayette-Gibson- Hardeman-Hardin-Haywood-Henderson-Henry-Lake-Lauderdale- Madison-McNairy-Obion-Tipton-Weakley.