329 FXUS64 KMEG 121744 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 1244 PM CDT Thu Jun 12 2025 ...New AVIATION... .KEY MESSAGES... Updated at 1233 PM CDT Thu Jun 12 2025 - Showers and thunderstorms will return to the Midsouth today. A few severe thunderstorms will be possible this afternoon and evening over north Mississippi, eastern Arkansas and southwest Tennessee. Damaging winds and flash flooding will be the primary threats. A brief tornado or two cannot be ruled out through this evening. - Scattered showers and thunderstorms will continue Friday through this weekend. At this time, the chances for severe thunderstorms appears limited. - Hot and humid conditions will develop next week, with isolated to scattered daytime showers and thunderstorms continuing. Heat indices will exceed 100 degrees by midweek. && .DISCUSSION... (Today through Wednesday) Issued at 325 AM CDT Thu Jun 12 2025 Gulf humidity will return to the Midsouth today in advance of a closed upper level low pressure system over TX. This feature has spawned several rounds of thunderstorms across TX in the past 24 to 48 hours. Early morning GOES water vapor imagery showed a leading shortwave over east TX that will eject through AR later today. Upstream of this feature, an second shortwave near the base of the upper low will eject through eastern AR tonight. These shortwaves, likely convectively-enhanced, will present more focused forcing for thunderstorms over the Midsouth than it appeared a few days ago. Regarding today`s the severe weather potential, 70s dewpoints will play a significant role in reducing convective inhibition, as well as enhancing low level CAPE for storm initiation. 0-6km shear will not be particularly strong this afternoon, generally less than 25 knots. The 06Z HRRR depicts deep layer shear increasing to 35 knots late tonight, associated with the second shortwave. By that time, storms will be rooted in an elevated layer, reducing but not precluding chances of severe wind gusts. Last several runs of the HRRR depict 700-500mb lapse rates of 5-6 C/km. With PWAT nearing 2.25 inches, severe hail will be a secondary threat, likely limited to discrete cells in the afternoon and early evening. Expect a similar story for Friday, but with slightly reduced severe weather potential in the wake of pre-dawn shortwave passage. PWAT values will remain above 2 inches. With weak deep layer shear and modest midlevel lapse rates, the main impact will likely be localized flash flooding and strong wind gusts. Similar conditions expected Sunday, though more of a focus east of the MS River, based on the eastward translation of the weakening upper level trough. Heading into next week, the upper low remnants will lift to the upper OH River Valley, with weak west-northwest flow prevailing over the Midsouth. Convective inhibition will remain weak, given continued high boundary layer humidity and relatively moderate midlevel temps (8-9C at 700mb). A weak northern branch shortwave trough is progged by deterministic GFS, ECMWF and CMC models to track southeast through the MO River Valley on Monday. Whether this impacts the Midsouth is in question. Outside of this feature, the main driver for daily rain chances through midweek will continue to be high boundary layer moisture and strong daytime heating. Wednesday`s heat indices are forecast to range from 100 to 105, as an upper ridge over TX expands eastward. PWB && .AVIATION... (18Z TAFS) Issued at 1240 PM CDT Thu Jun 12 2025 Tough TAFs this issuance. Main concern is TSRA with the movement of a frontal boundary this evening. As we remain in this summertime pattern, CAMs continue to struggle with exact timing of said convection. TEMPOs and PROB30s were drawn in to best fit thunderstorm activity. Ceilings will also drop from current VFR to MVFR and pockets of IFR as convection moves through this evening and early afternoon tomorrow. South/southwest winds will be at around 6-10 kts, with a few gusts up to 20 kts tomorrow afternoon. AEH && .FIRE WEATHER... Issued at 149 AM CDT Thu Jun 12 2025 High relative humidity return to the Midsouth today, accompanied by scattered showers and thunderstorms. High humidity and wetting rain chances will continue through the weekend. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...PWB AVIATION...AEH