Area Forecast Discussion
Issued by NWS Memphis, TN
Issued by NWS Memphis, TN
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087 FXUS64 KMEG 231006 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 506 AM CDT Sun Jun 23 2024 ...New SYNOPSIS, DISCUSSION... .SYNOPSIS... Issued at 505 AM CDT Sun Jun 23 2024 An approaching weak cold front combined with a warm, moist, and unstable airmass may result in the potential for isolated to scattered showers and thunderstorms across portions of the Mid- South, especially during peak daytime heating. A strong to perhaps isolated severe thunderstorm is possible with damaging winds and localized heavy rainfall as the main threats. This humid airmass combined with very hot temperatures will produce heat index values at or above 105 degrees at times through Tuesday. A cold front will bring a better chance for showers and thunderstorms on Wednesday with slightly cooler temperatures. A return of hot temperatures is possible towards next weekend. && .DISCUSSION... (Today through Saturday) Issued at 505 AM CDT Sun Jun 23 2024 GOES-16 Water Vapor satellite trends show a shortwave trough located from the Great Lakes Region back through the Central Plains. Latest surface analysis places a cold front from northern Illinois to northwest Missouri and southern Kansas. Regional WSR-88D radar trends show the trailing edge of showers and thunderstorms just upstream of the Mid-South over portions of southeast Missouri. Very warm and humid conditions persist ahead of this front with temperatures ranging from the lower 70s along the Tennessee River and middle 70s to around 80 degrees elsewhere. Short-term models including the latest CAMs show the upstream convection dropping into the northern third of the area this morning and weakening as better forcing moves east into the Ohio Valley. Model soundings indicate the potential for re-development as convective temperatures are reached during peak heating. Surface-based CAPE values rising to or above 2000 J/kg and around 20 kts of shear suggest a pulse-type character to any convection that develops. Isolated to low end scattered pops seem reasonable given the very conditional environment that will be in place across the area. Additionally, mid-level lapse rates are expected to be weak which may temper the overall severe weather threat to a degree. Damaging winds will be the primary severe weather threat if any thunderstorms can become severe. Localized heavy rainfall will also be possible as precipitable water values rise up to around 2 inches. Surface dewpoints are expected to pool ahead of this front today as temperatures rise into the 90s this afternoon. These hot temperatures combined with high dewpoints will result in heat index values rising at or above 105 degrees. Consequently, the existing Heat Advisory was expanded to cover the remainder of the Mid-South until early this evening. Additional Heat Advisories look likely especially along and west of the Mississippi River on Monday and across most of the Mid-South on Tuesday. Some uncertainty exists for heat headlines on Monday east of the Mississippi River as this front will result in slightly lower dewpoints. Long term operational and ensemble model trends continue to indicate a better potential for showers and thunderstorms across most of the Mid-South on Wednesday as a mid-level trough and associated cold front move through the Lower Mississippi and Tennessee Valleys. A few of these thunderstorms may have the potential to become strong to severe as the parameter space will be slightly better than today. Slightly cooler temperatures are expected for late this week followed by a return of very hot temperatures as the upper-level ridge builds back into the region by next weekend. CJC && .AVIATION... (06Z TAFS) Issued at 1133 PM CDT Sat Jun 22 2024 A slow-moving cold front will move into the Mid-South tomorrow morning and afternoon and trigger a few SHRAs and TSRAs. Although coverage is too low to carry prevailing weather at any particular site, VCSH and VCTS were carried. South winds will shift to the west as front moves through each site. AC3 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...Heat Advisory from noon today to 9 PM CDT this evening for ARZ009-018-026>028-035-036-048-049-058. MO...Heat Advisory from noon today to 9 PM CDT this evening for MOZ113-115. MS...Heat Advisory from noon today to 9 PM CDT this evening for MSZ001>017-020>024. TN...Heat Advisory from noon today to 9 PM CDT this evening for TNZ001>004-019>022-048>055-088>092. && $$ PUBLIC FORECAST...CJC AVIATION...ANS