Area Forecast Discussion
Issued by NWS Memphis, TN
Issued by NWS Memphis, TN
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442 FXUS64 KMEG 171730 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 1230 PM CDT Mon Jun 17 2024 ...New AVIATION... .UPDATE... Issued at 958 AM CDT Mon Jun 17 2024 Quick update. A plume of moisture rich air has arrived in the Mid-South this morning. The latest SPC mesoanalysis shows an area of PWAT values of 2.1 inches along and south of I-40. This plume of moisture will continue to lift north across the region through this evening. The main concern today will be instances of heavy rainfall as a weak shortwave pivots north through the Mid-South throughout the day. Rainfall rates will generally range between 2 and 4 inches with up to 6 inches with the deepest convection. Minor nuisance flooding is possible, especially in heavily populated areas. The forecast is on track with no big changes needed. PoP coverage will remain in the 40 to 60 range throughout much of the day with scattered to numerous showers and thunderstorms. Outside of showers and thunderstorms, heat indices will likely peak in the mid to upper 90s. AC3 && .SYNOPSIS... Issued at 351 AM CDT Mon Jun 17 2024 Slightly cooler conditions are expected today and tomorrow as a broad swath of rain moves in. Hot and dry weather returns by midweek with a gradual warming trend. Rain chances will pick back up early next week. && .DISCUSSION... (Today through Sunday) Issued at 351 AM CDT Mon Jun 17 2024 KNQA radar is currently picking up some light returns moving up from the Gulf Coast, foreshadowing what we`ll see this afternoon and again tomorrow. Coverage and intensity of these showers and eventually thunderstorms really starts to pick up around mid morning today, maximizing in the late afternoon. These storms have the potential to be very efficient rainfall producers; PWATs over 2 inches are above the 99th percentile of climatology between 18Z and 00Z today. In addition to the cooling rain, ample moisture will promote thicker cloud cover which will also help keep temperatures on the mild side today and tomorrow. NBM probabilistic guidance still suggests a low chance (10-40%) of temperatures above 90 degrees today, increasing slightly to about a 50% chance tomorrow. We should dry back out on Wednesday as a very anomalously strong upper level ridge begins to build over the Deep South. For context, NAEFS 200 mb heights are over 3 standard deviations above the mean for all hours from Wednesday afternoon to Sunday morning. Said ridge will eventually settle somewhere over the ArkLaTex region by late week, which spells out a warming trend for the Mid-South. Heat and humidity return on Thursday, continuing to warm further through the weekend. Forecast heat indices are back to triple digits areawide by Sunday. There may be some diurnally driven convection in the afternoons, but coverage will be so sparse that PoPs are generally between 5-10% each day through Saturday. Another pattern shift is on the horizon early next week. Two longwave troughs and their associated cold fronts look to dig across the northern and central Plains, one on Sunday and another following it next Tuesday. There`s still quite a bit of model discrepancy but this generally suggests an increase in rain chances (PoPs are about 20-40%) and perhaps a break from oppressive heat and humidity early next week, depending on how far south the fronts are able to make it. Stay tuned. CAD && .AVIATION... (18Z TAFS) Issued at 1230 PM CDT Mon Jun 17 2024 SHRA/TSRA is expected to continue across the Mid-South through this evening which may produce instances of MVFR CIGS with occasional IFR VIS. Later this evening, as precipitation diminishes across the airspace, VFR conditions are expected to prevail with the potential for shower activity across portions of the Mid-South tomorrow afternoon. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...CAD AVIATION...JPR