FXUS64 KJAN 201721 AAA AFDJAN Area Forecast Discussion...UPDATED National Weather Service Jackson MS 1221 PM CDT Sat Jun 20 2026 ...New AVIATION... .KEY MESSAGES... - Storms capable of producing heavy rainfall will bring an elevated (level 2 out of 4) flash flood threat today. - We will be monitoring a stormy weather pattern for additional flash flood and severe weather threats through the next week. - Increasingly dangerous levels of heat stress could return for much of the area Monday. && .DISCUSSION... Issued at 445 AM CDT Sat Jun 20 2026 The forecast area will remain in the interface region between a strong subtropical ridge axis centered to our southwest and an unseasonably strong longwave trough over the central/eastern CONUS. Northwest flow between these prominent features will support additional rounds of storms as we go through the weekend and upcoming work week. For Today through Sunday: The primary concern is storm development this morning associated with MCV activity embedded in a larger domain of cyclonic flow. The mesoscale ascent interacting with an unstable (most unstable CAPE up to 2000 j/kg) and very moist (precipitable water up to 2.2 inches) airmass will support elevated flash flood threat, especially given the antecedent conditions. Evolution of the the threat today is clearly centered along/north of the I-20 corridor through the morning, but becomes more nebulous as we go later into the day/afternoon. The ceiling on the heavy rain threat is not as high as in recent days and will hold off on any mention of significant FF concerns in the HWO graphics for now. Going into Sunday, a strengthening low level warm advection pattern will support disorganized and diurnally enhanced showers and storms with greatest rain chances centered on mainly the north half of the area while the ridge briefly exerts more influence. Monday through next Friday: Guidance has trended stronger and more suppressed with the westerlies, and this will result in continued storm threats with additional concerns for flash flooding/severe weather. As of now, it does not appear any of these threats will be significant, and limited/marginal categories should suffice for the most part. With that said, local mesoscale influences and antecedent conditions will drive any flash flood and severe weather threats on a daily basis, so monitor for updates as we go through time this upcoming week. It is also worth mentioning that heat may build to elevated threat levels Monday ahead of storms that move in later in the day and evening, and this would result in the need for messaging as we get closer. Going forward, heat stress could be a lingering issue for southern portions of the area, with areas farther north a concern if there is just a slight northward shift in the ridge axis from what is currently forecast. /EC/ && .AVIATION... (18Z TAFS) Issued at 1220 PM CDT Sat Jun 20 2026 The combination of ongoing convection and low clouds across the region will continue to result in a mix of VFR/IFR flight categories at area TAF sites through the afternoon. Convection will come to an end heading into this evening, with a return to mainly VFR/MVFR categories into tonight. Low stratus developing toward day break Sunday, along with some isolated to scattered convection, will again result in a degradation of flight categories to MVFR/IFR status. Winds today will steadily become more southern in the wake of convection, and will become calm to light from the south overnight. /19/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 73 88 75 92 / 20 50 0 10 Meridian 72 87 75 93 / 20 60 10 10 Vicksburg 74 89 76 91 / 20 50 0 10 Hattiesburg 75 88 76 94 / 30 50 0 10 Natchez 75 90 77 93 / 30 50 0 0 Greenville 73 89 76 91 / 10 60 20 60 Greenwood 72 89 76 91 / 20 70 20 70 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...Flood Watch until 7 PM CDT this evening for MSZ031>060. LA...Flood Watch until 7 PM CDT this evening for LAZ007>009-015-016- 023>026. AR...Flood Watch until 7 PM CDT this evening for ARZ074-075. && $$ 19