Area Forecast Discussion
Issued by NWS Memphis, TN
Issued by NWS Memphis, TN
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523 FXUS64 KMEG 071936 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 236 PM CDT Tue May 7 2024 ...New SYNOPSIS, DISCUSSION... .SYNOPSIS... Issued at 236 PM CDT Tue May 7 2024 Showers and thunderstorms will start out as isolated tonight and continue to increase in coverage and intensity by Wednesday. While there are severe weather chances today, there is highest confidence and concern for severe weather development on Wednesday night. Lingering showers and thunderstorms are possible on Thursday before a pleasant weekend. && .DISCUSSION... (This evening through next Monday) Issued at 236 PM CDT Tue May 7 2024 A few residual showers are depicted on KNQA as of 2 PM as a low pressure system pulls away from the region. Elsewhere most of the region will experience a brief lull in precipitation for the afternoon. Later this evening, a warm front will begin its northern ascent and may initiate convection. The 12z HRRR is very aggressive with this development across West Tennessee. The other CAMs and preceding HRRR runs are a bit less aggressive and have a quicker storm motion. The other CAMs are also have the storm mode more isolated and less organized so only Slight to Likely PoPs were carried. Confidence is low in severe weather criteria being met due to diurnal stabilization trends (storms may be elevated). Another limiting factor is models are hinting at this front stalling just to the northwest of the Mid-South resulting in a lack of forcing. Confidence continues to increase for severe weather potential tomorrow evening under a large Enhanced Risk for severe weather. A strong trough will interact with a surface low under strong upper level divergence to allow convection to commence. Despite this primed atmosphere, the greatest height falls are slightly to the north of the Mid-South. CIPS analogs have lesser probabilities than this time tomorrow currently at 60-70% as opposed to yesterday of 70-90%. These values are still indicative of organized convection generally along and north of Interstate 40. GFS soundings indicate MLCAPE values ~3000 J/kg, steep lapse rates, 40- 50 kts of effective shear, and a slight curvature to hodographs. Another concerning aspect is as trends continue to paint this as a nocturnal event, this means intensification of the LLJ. It is not likely that any morning showers and storms squash initiation as there is plenty of time to destabilize. Now is the time to prepare for damaging winds of 70+mph, quick spin up tornadoes that could be strong, and significant hail of 2" or greater. The line of storms should clear the area by 7 AM Thursday. Another upper level disturbance from the Gulf Region may bring some showers and thunderstorms Thursday afternoon and evening, mainly along and south of Interstate 40. Some thunderstorms may be strong to severe. On the brighter side, the weekend looks beautiful with dry and seasonable temperatures in the 70s. DNM && .AVIATION... (18Z TAFS) Issued at 1251 PM CDT Tue May 7 2024 TSRA initiation potential, timing and coverage remain the primary challenge in our modified tropical maritime airmass. HRRR remains the outlier in initiating TSRA from near NQA to MKL and points northward around 03Z this evening. NAM 3km depicts more limited TSRA coverage, primarily after 06Z, over far NW TN. Remaining CAMs remain largely dry tonight. For the MKL TAF, some deference has been given to the HRRR and latest TCF, resulting in retention of the PROB30 TSRA in the early overnight. Prefrontal ridging should cap TSRA develop Wednesday afternoon at MEM. Should this cap break, rapid TSRA development and intensification would be likely, given the considerable convective instability. For the TAF sites, this would mostly likely to occur at JBR, beyond the 24-hour TAF period. TSRA chances will ramp up considerably at JBR and MEM after 00Z Thursday / 7PM CDT Wednesday. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...DNM AVIATION...PWB