Forecast Discussion
096 FXUS64 KMEG 221709 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 1209 PM CDT Wed Apr 22 2026 ...New DISCUSSION, AVIATION, FIRE WEATHER... .KEY MESSAGES... Issued at 1209 PM CDT Wed Apr 22 2026 - High temperatures will be in the low to mid 80s through Thursday. Relative humidity will increase on Thursday, supporting isolated showers and thunderstorms along and west of the Mississippi River. - Warm and humid conditions will prevail Friday through early next week. There is a high chance for showers and thunderstorms on Friday afternoon and evening, with rain chances falling to 20 to 40 percent over the weekend. There is a low risk for strong to severe storms on Friday. - Conditions will be favorable for strong to severe thunderstorms on Monday. We continue to monitor this potential. && .DISCUSSION... (This evening through next Tuesday) Issued at 1209 PM CDT Wed Apr 22 2026 A more active weather pattern is setting up for the Mid-South over the next week or two, bringing multiple opportunities for showers and thunderstorms to the region. Currently, shortwave ridging is present over the Plains with a weak shortwave trough over the TN Valley. This upstream ridging will build east throughout the day as a prominent trough digs over the western CONUS. A few showers are ongoing from the Arklatex area into southeast AR, but dry air at the surface and large-scale subsidence will keep this activity mainly to our southwest, though there is a low chance for a few sprinkles in the delta. Expect another day in the lower 80s with southerly winds of 8- 14 mph. Southerly flow will ramp up moisture overnight and especially into tomorrow, with dewpoints climbing into the upper 50s and lower 60s by Thursday morning. This will promote a more robust Cu field during the daytime hours. The HRRR is indicating a few showers during the afternoon, but coverage looks to be very limited given the presence of the shortwave ridging and generally weak instability. The pattern change will become more evident by Friday as the aforementioned western trough moves east into the Plains. While the strongest 500-mb height falls will remain well to our north, there will be sufficient forcing for ascent to erode any cap within a diffluent, quasi-zonal flow aloft. Instability doesn`t appear to be an issue with MLCAPE on the order of 1000 J/kg to perhaps 1500 J/kg by peak heating. However, deep-layer shear will be more marginal at ~30 kts. There is a low chance for scattered showers in the warm sector on Friday morning, but more organized convection upstream will approach the Mid-South from the west in the afternoon. Given the weaker shear, it appears more likely than not that this activity will become outflow-dominant with the cold pools outpacing storm motion. A low-end risk for a severe wind gust or marginally severe hail cannot be ruled out on Friday afternoon and evening, but the greatest risk looks to be to our west. NBM probabilities for at least 1" of rainfall are in the 40- 60% range with this system, but the LREF (EPS, GEFS, and GEPS) tops out at ~20%, suggesting that the NBM is suffering from some QMD bias correction issues and is being influenced by the wetter GEPS. Ensemble guidance is in strong agreement that the western trough will stall over the northern Plains through the weekend and into early next week. The first shortwave trough on Friday will lift into the Great Lakes by Saturday morning, but we`ll maintain a broad quasi-zonal flow aloft through the weekend. The next significant wave will be approaching the Mid-South by early next week, but this pattern looks favorable for weak perturbations in the westerly flow aloft to maintain at least 20-40% PoPs for Saturday and Sunday. Temperatures will top out in the lower 80s each day with morning lows in the upper 50s to lower 60s. We continue to monitor Monday`s severe weather potential. Like the Friday system, the strongest forcing will remain to our north. In this case, both shear and instability look to be on the stronger side, but deterministic guidance is hinting at the presence of a capping inversion in the 850-700 mb layer. Mid- level lapse rates look to be rather steep, and hodographs show strong cyclonic curvature. This is certainly a scenario that needs to be watched closely for severe weather, but there remain plenty of details that will need to be ironed out before confidence increases. However, at this time, all modes of severe weather are on the table, given the potentially volatile setup. Quasi-zonal flow aloft persists on the backside of this trough, maintaining low rain chances through midweek. && .AVIATION... (18Z TAFS) Issued at 1209 PM CDT Wed Apr 22 2026 Confidence remains high for VFR conditions to prevail at all TAF sites while some mid-level moisture moves across the Lower Mississippi Valley, producing clouds between 6-9kft. South winds will increase this afternoon with gusts up to 20 kts at MEM and MKL, and 25 kts at JBR. && .FIRE WEATHER... Issued at 1209 PM CDT Wed Apr 22 2026 Minimum relative humidity will fall to 25-35% across much of the Mid-South again today (more like 30-40% west of the Mississippi River) with southerly 20-ft winds of 8-14 mph through sunset. This will result in another day of elevated fire weather concerns. RH will moderate Thursday and Friday as low-level moisture increases ahead of the next system. A wetting rain is likely area wide Friday afternoon into the overnight period as showers and thunderstorms traverse the region. There remains a low chance (20-40%) for showers and thunderstorms Saturday and Sunday, but the next significant system will bring another round of thunderstorms on Monday. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...MJ AVIATION...CMA