Forecast Discussion
280 FXUS64 KMEG 240455 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 1155 PM CDT Thu Apr 23 2026 ...New DISCUSSION, AVIATION, FIRE WEATHER... .KEY MESSAGES... Issued at 1155 PM CDT Thu Apr 23 2026 - Unsettled weather will return to the Midsouth on Friday with a Slight Risk (2/5) of severe weather to the south and west of Memphis. Damaging wind gusts are the main concern, but large hail and a tornado or two cannot be ruled out. Additional showers and thunderstorms will remain in the forecast through the weekend. - Conditions continue to look favorable for strong to severe thunderstorms on Monday, with at least a 30% chance in some locations. Please continue to monitor the forecast over the weekend. && .DISCUSSION... (Tonight through next Thursday) Issued at 1155 PM CDT Thu Apr 23 2026 After an extended period of warm and dry weather, the Midsouth is on the threshold of a stormy and unsettled pattern. The ingredients appear to be coming together for a pronounced severe threat on Monday. Late Thursday evening, GOES water vapor imagery showed a larger upper low complex over the northern Rockies. A fast zonal southern branch of the upper jet extended around the southern periphery of the upper low over the central Rockies. This downstream flow was diffluent over the Missouri and middle- Mississippi River Valleys, aiding linear thunderstorm complexes that extend from northern Oklahoma to western Lake Superior. Through the remainder of the night, storms will continue east into the lower Ohio River Valley and Ozarks, in tandem with midlevel height falls. Marginal CAPE will limit storm intensity over the lower Ohio River Valley, where dewpoints are around 15F cooler than over AR and southern MO. Storms should take a south/southeast path through central AR toward sunrise, generally following the orientation of the midlevel thickness gradient. The CAMs, and the HRRR in particular, depict these storms over AR will be generally balanced with respect to shear and outflow. From Memphis to the north and east, storms will likely be more outflow-dominant encountering weaker CAPE, weaker deep-layer shear and presenting a lower severe weather threat. Later in the day Friday, convection will likely reinvigorate along the remnant outflow boundary in north MS. 00Z HRRR depicts surface-based CAPE over north MS running from 600-800 J/kg, though 0-6km bulk shear is less than 30KT over northeast MS. Weak zonal flow aloft will prevail Friday night, as the remnant boundary stalls over central MS roughly parallel to the midlevel flow. Weak easterly low level flow will prevail Saturday. There will be sufficient moisture and surface-based CAPE to support isolated thunderstorms driven by daytime heating. Another southeast- propagating MCS will likely pass through the Ozarks late Saturday night early Sunday morning. Model consensus keeps the bulk of storms over central and western AR, near the low level theta-e ridge. Sunday will be a similar scenario to Saturday, with daytime heating providing instability. Weak deep layer shear should limit the severe threat. By Sunday night, low amplitude shortwave ridging will lift off to the east, as increasingly diffluent flow arrives from the west, portending a busy day ahead on Monday. The newly-arrived 00Z GFS has not deviated from earlier solutions that depict an impressive convective parameter space. A neutral to slightly negatively-tilted high amplitude trough will lift into the middle to upper Mississippi River Valley by late Monday afternoon, with an attendant surface low over the upper Midwest. Closer to the Midsouth, the GFS depicts a more compact but impactful southern branch shortwave trough phasing with the northern branch counterpart. The southern branch shortwave trough could increase the chances of a surface frontal wave that backs surface inflow, as well as increasing the potential for a stronger rear inflow winds into the storms in mid to late afternoon. Convective parameters are otherwise impressive, with MLCAPE near 3500 J/kg late Monday afternoon, and midlevel lapse rates of 7.5 to 8.3 C. GFS-derived Supercell composite of 8 to 16 suggest a potential for discrete cells, increasing the concern for large hail. Curved hodographs and 0-3km SRH of 300 m2/s2 would be supportive of tornadoes. While this is one medium range model, the 00Z GFS is consistent with the 12Z LREF consensus from earlier today. The machine learning GEFS convective analog from Colorado State University depicts a hatched 48% severe probability centered over West Tennessee on Monday. While this is all medium range guidance, the big picture is coming into focus. The details will become more clear once we`re in the 48 to 60 hour CAM window. && .AVIATION... (06Z TAFS) Issued at 1155 PM CDT Thu Apr 23 2026 Other than some mild southwesterly LLWS around FL015, the rest of the overnight period will be quite benign. Things start to pick up mid Friday morning with the approach of a line of thunderstorms ahead of a cold front. Widespread SHRAs are expected to start up around 15Z with embedded TSRA through the afternoon hours as the front traverses the airspace. Given the stronger intensities on the leading edge, MEM and JBR are most likely to be directly impacted by TSRA. Guidance has come in more pessimistic on the post-frontal stratus overnight tomorrow; ceilings will most likely start to tank after 03Z Saturday to MVFR and eventually IFR after 06Z. && .FIRE WEATHER... Issued at 1155 PM CDT Thu Apr 23 2026 Wetting rainfall will return to the Midsouth on Friday, followed by continued chances of wetting rains over the weekend. Widespread thunderstorms are expected Monday, with moderate to high humidity and chances of rain continuing through much of next week. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...PWB AVIATION...CAD