964 FXUS64 KMEG 282345 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 645 PM CDT Tue Apr 28 2020 .UPDATE... Updated for 00Z Aviation Discussion. && .PREV DISCUSSION... /issued 325 PM CDT Tue Apr 28 2020/ DISCUSSION... A weak leading shortwave lifting northeast out of the Arklamiss was aiding in the development of storms over the MS River delta this afternoon. This shortwave was evident on KNQA radar, upstream from storms lifting northeast through the delta. These storms were rooted in an elevated layer and will present a marginal threat (at most) for large hail through late afternoon. Midafternoon GOES water vapor imagery showed a double-centered upper low over the western Dakotas, and another upper low near Duluth MN. These three low pressure centers will combine into one deep upper low dropping into the mid-MS River valley by Wednesday morning. A line of storms over eastern KS/northwest MS will likely expand in areal extent will moving southeast this evening and overnight. Main directed cold pool push will likely occur to the west and south of the Midsouth, toward the Red and Sabine River valleys, into the low level instability axis. Closer to home, convection-allowing model (CAM) consensus depicts a couple of bowing segments to the north, over northeast AR. Last couple of HRRR runs depicted the northern extent of the convective line dissipating earlier over the Midsouth, by around 2 AM. Too early to jump on one CAM solution, but this may point toward a lower-end event for portions of the Midsouth east of the MS River. One axis of the multi-lobe upper low will drop through the Midsouth toward midday Wednesday. NAM model depicted a band of steep isentropic downglide behind this feature, suggesting some momentum from stronger winds aloft will reach the ground. That said, 925-850mb winds are depicted 25 to 30 knots, less strong than with the previous couple of upper low pressure systems. Following showers and perhaps isolated high-based thunderstorms Wednesday, the remainder of the week will see an upper level ridge translate east to the MS River through Saturday, gradually deamplifying during the process. Daytime temps over the Midsouth should warm well into the 80s this weekend. Next rain event will arrive with a return to northwest flow and associated cold frontal passage Sunday into Monday. PWB && .AVIATION... /00Z TAFs/ KNQA showers a few showers and isolated thunder across northern MS at this hour with the main line of convection entering into NW Arkansas. High clouds and strong southerly winds will persist across the Mid-South for the next few hours. LLWS is still expected to develop along and east of the MS River ahead of an approaching cold front. This main line of storms back to the west will quickly move across the Mid- South overnight. Maintained the TEMPO groups for TSRA/IFR VIS at all TAF sites. As early as 05Z at JBR and 06Z at KMEM. However, this will need to monitored as any cold pool development could lead to a quicker onset to convection than what hi-res guidance is showing. MVFR cigs will develop shortly after the passage of the main line of convection. Similarly S/SW winds will veer to the W and eventually to the NW remaining elevated and periodically gusty. VFR conditions should return to all of the Mid-South by tomorrow afternoon. 17 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$