Forecast Discussion
986 FXUS64 KMEG 171133 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 633 AM CDT Thu Apr 17 2025 ...New AVIATION... .KEY MESSAGES... Updated at 630 AM CDT Thu Apr 17 2025 - Significant river flooding continues across much of the Mid-South. - A warming trend will continue through the end of the week. - Scattered showers and thunderstorms are expected to return to the Mid-South this weekend as a slow moving front moves through the Middle and Lower Mississippi Valleys. Severe weather will be possible this weekend. && .DISCUSSION... (Today through Wednesday) Issued at 330 AM CDT Thu Apr 17 2025 A pleasant night is on display at this hour with current temperatures in the upper 40s to lower 60s with mostly light winds at the surface. A very thin altostratus deck is currently moving southeast, across our area as upper level ridging continues to build in over the region. Dry conditions will prevail today with highs generally in the low to mid 80s as aforementioned ridging sets in over the Mid-South. Tomorrow, a surface warm front will push across the area while in the upper levels, southwest flow will build in. Thus, tomorrow will be a pretty warm one with highs in the mid to upper 80s. Portions of northeast Arkansas and the Missouri Bootheel will be quite windy today and tomorrow with strong return flow. Had thoughts of a Wind Advisory over these counties for today, but went ahead and held off as we`ll likely fall just short of criteria. Tomorrow looks to be more of a slam dunk for 40 mph+ wind gusts, a Wind Advisory may need to be issued in the next forecast package. By tomorrow evening, a surface low pressure system will move into the upper Great Lakes Region, pushing a cold front into the Middle and Upper Mississippi Valleys. This front will stall just north of the Missouri and Kentucky stateline while ridging holds strong over areas along and south of the interstate 40 corridor. Scattered showers and thunderstorms will move over areas north of I-40 as this front stalls for much of the day Saturday. One thing to note, this front looks to slow and stall a little more northwest of our area than previous thinking`s. Thus, shower and thunderstorm probs Saturday have been held to more northwestern portions of the Mid-South comparative to previous runs. A very conditional chance for severe weather exists in these far northwest counties as joint probs for SBCAPE values greater than 1000 J/kg and 0-6 km bulk shear values greater than 30 kts are only around 35%. Come Sunday morning, a negatively tilted trough will eject from the southern Rockies and pivot into the Middle Mississippi Valley, pushing the aforementioned cold front across the rest of the Mid- South. Even though we`re only four days out, uncertainty still exists with the onset, timing, and intensity of showers and thunderstorms moving into Sunday. Depending on when the negatively tilted trough axis interacts with the instability and moisture axis, a few different solutions could play out with severe weather. The GFS continues to hold strong with the faster solution, pushing the main storm system across the Mid-South Sunday afternoon through early Monday morning. Where as the slower solution, the EURO, has storms not initiating until Sunday evening. Therefore, be prepared for severe weather as early as Sunday afternoon and extending into Monday morning. The best instability axis and thermodynamic set up aligns with Sunday afternoon into evening with joint probs greater than 60% for 700 J/kg of SBCAPE and 30 kts of 0-6 km bulk wind shear and decent height falls. Forecast QPF amounts this weekend are upwards of 1.25 inches over portions of the Missouri Bootheel and northeast Arkansas, and less than a quarter of an inch along and south of I-40. Persistent river flooding over northeast Arkansas and the Missouri Bootheel will be at risk with increased rainfall this weekend. Something to keep an eye on. High pressure and upper level quasi-zonal flow will follow behind the aforementioned front Monday afternoon. By Tuesday, upper level ridging will begin building in with a few embedded shortwaves, thus, very isolated showers and thunderstorms could form along these. The weather pattern will become unsettled mid- week next week. Stay tuned.. AEH && .AVIATION... (12Z TAFS) Issued at 630 AM CDT Thu Apr 17 2025 VFR conditions continue. Winds will become predominantly southerly after 16Z, with gusty winds by that time that will continue throughout the current TAF period. LLWS looks likely generally between 02Z and 09Z at all TAF sites (04Z to 10Z for TUP). && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...AEH AVIATION...CMA