FXUS64 KMEG 081801 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 101 PM CDT Wed Jul 8 2026 ...New DISCUSSION, AVIATION, FIRE WEATHER... .KEY MESSAGES... Issued at 101 PM CDT Wed Jul 8 2026 - Temperatures and humidity will gradually increase through Friday. Heat index values will approach 105 degrees on Thursday and Friday for portions of the Mid-South, especially areas along and west of the Mississippi River. The heat will continue into the weekend. - A slow-moving upper-level disturbance will aid in the development of showers and thunderstorms through the middle of next week. The stronger storms will be capable of producing gusty winds and heavy rainfall. && .DISCUSSION... (This evening through next Tuesday) Issued at 101 PM CDT Wed Jul 8 2026 A compact upper-level low continues to spin over the lower OH Valley today. This feature will continue to provide large-scale ascent across the region, aiding the development of scattered convection this afternoon. The environment remains very moist, with precipitable water (PWAT) near 2.0" across the CWA. Very weak deep-layer shear and a modicum of mid-level dry air will again result in an environment favorable for locally heavy downpours and perhaps a few microbursts. That said, the severe weather threat remains generally low today. Convection will likely continue into the early evening hours with a few cells potentially persisting longer. PoPs were extended after 7 PM in some areas. Temperatures will be similar to yesterday, with highs in the upper 80s and lower 90s. The heat is expected to build slightly on Thursday and Friday, with highs climbing 2-4 degrees across the CWA. This is in response to the aforementioned upper-level trough moving east toward the Appalachians. This should lead to slightly lower diurnal coverage of thunderstorms and less cloud cover. The NBM is pushing heat indices to 105-109 degrees tomorrow afternoon, mainly in the MS delta and west of the MS River. However, the NBM appears to be overdoing dewpoints and may have a slight warm bias. It's not out of the question that a few areas reach 105F (heat index), but coverage should be low enough to preclude a Heat Advisory. Will let the next shift reassess this potential. Otherwise, expect scattered diurnal convection with an early evening lull. CAMs continue to indicate increasing convective development Thursday night as activity upstream over MO/KY moves ESE into portions of the MO Bootheel, far northeast AR, and northwest TN. PWATs remain high, and the guidance indicates the potential for training storms in this corridor. The flooding risk will primarily be driven by short-duration rainfall rates (especially in more urban areas), but there is a potential for 2-3+ inches of rain should all ingredients come together. A Flood Watch has been issued to account for this flooding risk, roughly along and north of a line from Corning, AR, to Dyersburg, TN, to Parsons, TN, beginning at 1 PM Thursday. This watch will continue through Friday and Saturday, given the likelihood of daily redevelopment. There is also a slightly higher risk for severe weather on Friday given the strong instability and potential for microburst activity. The marginal risk (level 1/5) captures this risk sufficiently. Moving into the weekend, the upper-level ridge quickly builds over the Rockies and Northern/Central Plains, with 500-mb geopotential heights near or just above 600 dam by early next week. These heights exceed climatology for the Northern Plains, indicative of a very strong upper-level ridge. The good news is that we'll be removed from the anomalous mid-level heights on the southern periphery of the ridge, limiting our temperature-related impacts. This pattern will result in deep easterly flow that will maintain a relatively moist, unstable air mass Monday through midweek. Expect the status quo of afternoon/evening convection each day with temperatures remaining near or slightly below climatology. There is still a fair amount of uncertainty about how this pattern will evolve during the latter half of the week. Will the ridge retreat over the western CONUS, or will it persist over the middle of the country? A slight majority of the GEFS members (and to a lesser degree the EPS) are more aggressive with the trough digging over the eastern CONUS by mid/late next week. This builds the western ridge, promoting northwest flow aloft across the Mid- South. This pattern would likely result in lower diurnal PoPs due to a drier air mass, but could also open the door for MCS activity. Still a lot of details to sort through with these scenarios. && .AVIATION... (18Z TAFS) Issued at 101 PM CDT Wed Jul 8 2026 The main aviation concern over the next 24 to 30 hours will be chances for convection. Storms have already formed this afternoon in the Mid-South and will generally move off to the east and east southeast. Coverage should not be overly widespread; therefore will account for thunderstorm potential with PROB30 groups. Locally reduced visibility and ceilings are likely if a thunderstorm directly impacts a terminal. Otherwise, expect VFR conditions to prevail. Winds through the period will generally be out of the southwest to south and less than 10 knots. && .FIRE WEATHER... Issued at 101 PM CDT Wed Jul 8 2026 No fire weather concerns are anticipated across the Mid-South through the next week. Minimum relative humidity is forecast to remain above 40 percent each day with generally light 20-foot winds. Showers and thunderstorms will be possible each day, with the most likely time during the afternoon and early evening hours. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...Flood Watch from Thursday afternoon through late Saturday night for ARZ009. MO...Flood Watch from Thursday afternoon through late Saturday night for MOZ113-115. MS...None. TN...Flood Watch from Thursday afternoon through late Saturday night for TNZ001>004-019>022-054-055. && $$ PUBLIC FORECAST...MJ AVIATION...TAB