Forecast Discussion
213 FXUS64 KMEG 281921 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 221 PM CDT Tue Apr 28 2026 ...New MESOSCALE UPDATE... .KEY MESSAGES... Issued at 220 PM CDT Tue Apr 28 2026 - Another round of severe weather is expected this afternoon into the late evening hours. All hazards will be on the table, particularly damaging winds. - Another chance for showers and thunderstorms arrives on Friday with a weak reinforcing cold front. Otherwise, generally dry and progressively cooler weather is expected through the weekend. && .MESOSCALE UPDATE FOR SEVERE WEATHER... Issued at 220 PM CDT Tue Apr 28 2026 Large-scale forcing for ascent associated with an approaching mid- level shortwave trough will enhance lift across the Mid-South through this evening. This wave is accompanied by another band of strong mid-level flow that will maintain strong deep-layer vertical shear. The boundary layer continues to destabilize with MLCAPE near 3000 J/kg, per the latest RAP analysis, with 0-3 km CAPE approaching 150 J/kg in some areas. The combination of instability and shear will maintain the convection moving into eastern AR, and facilitate upscale growth into a mixed-mode mess of supercells and multicell clusters/line segments. Damaging wind and hail look to be the most likely hazards. However, 0-1 SRH is progged to increase later this afternoon to perhaps ~150 m2/s2 (the strongest SRH seen on the SPC mesoanalysis substantially lags behind the convection). WFO Memphis is entering warning operations and will forego the issuance of the SPS for subsevere storms. The latest intel suggests that the first wave of convection will move across the area between now and sunset with a secondary wave late this evening. Confidence is much lower on the secondary wave, and a lot will depend on how much recovery the air mass experiences post-convection. MJ && .DISCUSSION... (This evening through next Monday) Issued at 111 PM CDT Tue Apr 28 2026 A very brief lull in convection is underway this late morning across the Mid-South. There will be a messy convective scheme unraveling over the next 2-3 hours as a strong cold front makes its final approach. Severe thunderstorms are ongoing over NW AR and SW MO, which will become our main focus for this afternoon. According to the latest CAMs, convective mode will be multicellular with a high potential for bowing segments, especially across the Mississippi Delta. These bowing segments will feature our highest damaging wind threat - most likely in the 3-7PM time frame today. It`s worth noting that there continue to be considerable timing discrepancies even in the highest resolution models this afternoon. The grand ensemble of the HREF attempts to smooth out these inconsistencies, but the HRRR has handled the observed convection best so far and it favors an earlier solution by 2-3 hours compared to the remaining CAMs. Hazard-wise, all threats are on the table today. As previously alluded to, the convective mode favors a significant damaging wind threat across north Mississippi this afternoon. While this is the primary hazard, the low level shear profile is supportive of embedded tornadoes, some of which could become strong (EF-2+). Digging into some point soundings, there is noteworthy curvature in the lowest level of the hodographs indicative of rotating supercells. Midlevel lapse rates have been very impressive throughout this multi-day event and will continue to support very large hail this afternoon at over 7 degC/km. Somewhat of a sleeper threat may be the heavy rainfall. While these storms will be fairly progressive in their eastward movement, a training situation may unfold across the southern half of our area. PWATs are above the 97.5th percentile for this time of year, which will support very efficient rainfall rates passing over the same areas within a few hours of each other. Storm total QPF is manageable for most of the area at around 1.5 inches through tomorrow, but it creeps up to near 2.5 inches along our southernmost zones. Especially with the Memphis metro, flooding will be a sneaky hazard today. After the convection moves through tonight, we should be all clear of severe weather no later than 1AM. This is a very slow- moving front and thus we`ll still have some straggling post- frontal showers over north MS for much of the day Wednesday. Following this frontal passage and a weak reinforcing front on Friday, cool high pressure will settle in nicely for the next few days. Temperatures take a steady dive and end up about 10 degrees below normal by this weekend with highs in the 60s. As southerly flow returns on the back side of the exiting high pressure system, we warm back up to near normal next week. However, the long range forecast does favor a 30-40% chance of below normal precipitation so we may be entering another mild pattern. && .AVIATION... (18Z TAFS) Issued at 111 PM CDT Tue Apr 28 2026 Multiple TSRA clusters will track eastward out of central AR into the Midsouth late afternoon. The HRRR model has been relatively consistent with its depiction of convective timing of the initial TSRA through the TAF sites. For this evening, the HRRR has since trended toward the other CAMs that depict SHRA and isolated TSRA near MEM over the latter half of the late evening inbound push. There is some question with regard to available convective instability. But should an area of organized post-frontal SHRA develop, vertical thermal profiles suggest at least a sparse coverage TSRA could be supported through 08Z. && .FIRE WEATHER... Issued at 111 PM CDT Tue Apr 28 2026 Multiple rounds of showers and thunderstorms will move through this afternoon and evening, resulting in 1-2" of rain areawide to mitigate fire danger. Dry conditions with minRH values below 40% will materialize on Thursday, before additional moisture returns on Friday. The weekend looks dry again with minRH dipping back below 40%. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ MESOSCALE UPDATE...MJ PUBLIC FORECAST...CAD AVIATION...PWB