Forecast Discussion
455 FXUS64 KMEG 220442 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 1142 PM CDT Tue Apr 21 2026 ...New DISCUSSION, AVIATION, FIRE WEATHER... .KEY MESSAGES... Issued at 1141 PM CDT Tue Apr 21 2026 - Highs in the low to mid 80s are forecast 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 the weekend. Shower and thunderstorms will peak near 90% on Friday and remain in the 30-50% range through the weekend. Conditions will be favorable for strong to severe thunderstorms on Monday. && .DISCUSSION... (Tonight through next Tuesday) Issued at 1141 PM CDT Tue Apr 21 2026 A wet and unsettled weather pattern remains on track to arrive late this week. In the interim, high temperatures will average 5 to 10 degrees above normal under transitory upper level ridging. Relative humidity will gradually moderate today (Wednesday), but will ramp up considerably behind a warm frontal surge on Thursday. CAM consensus suggests isolated showers and thunderstorms may precede the surface warm front - mainly along and west of the MS River from midmorning into the early afternoon. Thursday`s isolated convection will precede considerably higher chances of showers and thunderstorms on Friday. A longwave trough axis will rotate through the central and northern Great Plains Friday afternoon, preceded by a southern branch shortwave ejecting from the Red River Valley into the Ozarks. Remnants of an upstream MCS tied to this shortwave will likely enter eastern AR Friday morning and continue eastward along a sagging Pacific cold front Friday afternoon. Per 12Z LREF, storms will have access to 500-750 J/kg of MLCAPE and 25 to 30KT of deep layer bulk shear, sufficient to support an isolated severe storm threat. Storms should exit the Midsouth Friday evening as the front exits north MS. Isolated storms will be possible Saturday afternoon, before diffluent flow aloft brings increased storms chances Sunday. A rather potent-looking negatively-tilted shortwave trough axis appears likely to rotate through the Ozarks Monday morning, though medium range 12Z/18Z model consensus on timing is marginal. If the slower solution from the GFS-based guidance verifies, we could see this potent trough axis ejecting through the Midsouth during peak heating Monday. Stay tuned for this potential severe weather setup. The pattern looks to remain unsettled early next week, as the southern branch wave train continues over the eastern Pacific and western U.S.. && .AVIATION... (06Z TAFS) Issued at 1141 PM CDT Tue Apr 21 2026 VFR conditions will prevail through the period while some mid- level moisture moves across the Lower Mississippi Valley and produces some clouds between 6-9kft. Light south winds are expected to increase Wednesday afternoon with a few occasional gusts approaching 20 kts. && .FIRE WEATHER... Issued at 1141 PM CDT Tue Apr 21 2026 Fire weather danger will moderate slightly on Wednesday as winds will be less strong and minimum relative humidity prevails at 25 to 35%. Relative humidity will increase further on Thursday, supporting low chances of wetting rainfall along and west of the Mississippi River. Medium to high chances for wetting rainfall returns Friday through the weekend. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...PWB AVIATION...CJC