Forecast Discussion
266 FXUS64 KMEG 300453 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 1153 PM CDT Thu May 29 2025 ...New AVIATION... .KEY MESSAGES... Updated at 1149 PM CDT Thu May 29 2025 - A conditional chance for severe thunderstorms exists over the entire Mid-South tonight with primary threats of damaging winds and large hail, though a tornado or two can not be ruled out. Rain chances will taper off by Friday morning. - Mostly dry weather will prevail Friday and until early next week as the pattern becomes unsettled. && .DISCUSSION... (This evening through next Wednesday) Issued at 203 PM CDT Thu May 29 2025 Latest surface analysis depicts an upper level low and attendant cold front near the OK/AR/MO state lines, with the cold front stretched through southeast OK and northern TX. This cold front will materialize a bit deeper from its parent upper trough and cross the Mississippi Valley tonight being responsible for our Marginal Risk (level 1/5) for severe thunderstorms. The aforementioned parent trough stretched a warm front that crossed over the Mid-South earlier this morning, resulting in dewpoints to climb into the upper 60s and low 70s. These dewpoints are favorable for sufficient SBCAPE values between 1000-1500 J/kg, which coincide with the Marginal Risk. While we have decent surface instability, shear and instability in the mid-levels are limiting factors. Mid-level lapse rates should remain between 5-6 C/km and effective shear should remain less than 45 kts. Deterministic soundings do indicate very low LCLs which could cause a thunderstorm to produce damaging winds, quarter sized hail, and a tornado or two cannot be ruled out. PWATs are around 1.6" which is average climatology for this time of year, but heavy rainfall could aggravate already saturated soils which could result in some minor urban and small stream flooding. The low pressure system has yet to tap into a stronger LLJ, resulting in a delay of convection initiation over the Mid-South. Severe storms could start to fire up around 5 PM and travel ESE across the region. Since surface based instability is the best parameter today, once the sun begins to set and diurnal instability trends commence, the severe weather window will slowly begin to close. Showers and thunderstorms will continue after midnight and taper off by morning as the cold front pulls away from the area. High pressure looks to quickly settle in Friday afternoon with cooler air to filter in behind the front. This weekend will be beautiful with mostly dry conditions under northwest flow. A perturbation or two could cause a stray shower or two along the Tennessee River on Sunday, but given a few days of high pressure, accumulation is negligible. Early next week, looks to result in a pattern shift, into a more summer like regime as a warming trend kicks off. A deep trough looking to form in the Rockies is likely to return widespread rain chances by the middle of next week. DNM && .AVIATION... (06Z TAFS) Issued at 1149 PM CDT Thu May 29 2025 A cold front will pass through all sites over the next few hours. Scattered SHRAs and TSRAs will affect the northern sites with mainly SHRAS to the south. MKL will have the best shot of prevailing SHRAs and TSRA. MVFR CIGs will accompany the frontal passage and mix out by late morning at all sites. Northwest winds will persist between 8 and 12 knots with occasional gusts in the afternoon hours. AC3 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...DNM AVIATION...AC3