Area Forecast Discussion
Issued by NWS Memphis, TN
Issued by NWS Memphis, TN
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109 FXUS64 KMEG 061152 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 652 AM CDT Mon May 6 2024 ...New AVIATION... .SYNOPSIS... Issued at 522 AM CDT Mon May 6 2024 Shower and thunderstorm chances are expected to become isolated into this afternoon as an upper-level disturbance moves away from the Lower Mississippi Valley. An active period of weather is expected for Tuesday into Wednesday night as a series of troughs move through the Mississippi and Ohio Valleys. Severe thunderstorms are possible Tuesday afternoon into Tuesday evening, and especially Wednesday night. Cooler and drier air is anticipated for the upcoming weekend. && .DISCUSSION... (Today through Sunday) Issued at 522 AM CDT Mon May 6 2024 GOES-16 satellite this morning show the remnants of an MCV centered near St. Louis. Nocturnal convection developed near the nose of a 35 kt low level jet. This resulted in strong to severe thunderstorms and heavy rainfall overnight especially over north Mississippi where a corridor of instability between 1000-1500 J/kg and 35 kts of shear existed. Convective activity has since waned over the past hour with showers and thunderstorms located over north Mississippi and portions of West Tennessee near the Tennessee River. Strong to severe thunderstorms through mid-week remain the primary concern in this morning`s forecast issuance. Short-term models suggest rain chances will gradually diminish today in wake of the overnight convection as the atmosphere stabilizes somewhat. Some CAMs indicate the potential for some isolated showers and thunderstorms this afternoon. However, confidence in occurrence and coverage remains low at this time as shortwave ridging builds in across the Mid-South. Additional showers and thunderstorms are expected to develop across the Central and Southern Plains tonight as a mid-level trough becomes negatively tilted and moves into the Middle Mississippi Valley. This upstream activity is anticipated to weaken as it moves towards the Mid-South late tonight into a somewhat stable atmosphere. Instability is expected to increase into Tuesday afternoon/evening with redevelopment of showers and thunderstorms expected especially east of the Mississippi River. The aforementioned surface-based instability combined with moderately steep mid-level lapse rates and deepening shear suggest a potential for strong to severe thunderstorms with large hail and damaging winds as the main threats. Confidence continues to increase with the potential for organized severe thunderstorms across the Mid-South Wednesday into Wednesday night as a shortwave mid-level trough rotates around an upper- level low through the Middle Mississippi and Ohio Valleys. Meanwhile, a surface low is expected to move across northeast Missouri and northern Illinois. Favorable upper-level divergence produced by the left exit region of a sub-tropical jet and perhaps the right exit region of the polar jet combined with deep directional and speed shear, very steep mid-level lapse rates, and strong instability favor the potential for large hail, damaging winds, and tornadoes. Colorado State University machine learning guidance and St. Louis University CIPS analogs support the potential for organized severe weather across the Ohio Valley and Mid-South Wednesday afternoon and Wednesday night. At this time, it appears the greatest threat for severe thunderstorms across the forecast area will be Wednesday night as a capping inversion may be in place across much of the Mid-South. This potential severe weather event will be closely monitored over the next couple of days. Stay tuned... Long-term models indicate some residual showers and thunderstorms will be possible on Thursday with cooler and drier air filtering in for Friday into the upcoming weekend. CJC && .AVIATION... (12Z TAFS) Issued at 642 AM CDT Mon May 6 2024 An upper level disturbance is currently pivoting through the region. A lone supercell continues to fire along a boundary southeast of MEM. Scattered SHRAs and TSRAs are possible through late morning, mainly near MEM and MKL. MVFR/IFR CIGs will continue to affect JBR and MEM through late morning. Most SHRA activity will be out of the region by late morning and early afternoon. Thereafter, all sites will return to VFR. Another round of SHRAs will arrive near the end of the period along with MVFR CIGs. AC3 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...CJC AVIATION...AC3