FXUS64 KJAN 220219 AAA AFDJAN Area Forecast Discussion...UPDATED National Weather Service Jackson MS 919 PM CDT Fri Aug 21 2026 ...New MESOSCALE UPDATE, AVIATION... .KEY MESSAGES... - Dangerous heat stress across at western portions of the forecast area again Saturday. && .MESOSCALE UPDATE... Issued at 919 PM CDT Fri Aug 21 2026 Rest of tonight... Frontal zone is draped just north of Interstate 20, with expectations that this will continue to dive southward into the overnight hours. Synoptic pattern remains with deep broad troughing and stout ridge (597-600DM at 500mb) over the Four Corners. Drier air is situated north of the frontal zone, with deeper moisture to the south. Earlier rain and active storm period has shifted southward, so rest of the evening should remain much quieter. There will remain some cloud cover overnight for areas , but clearing to the north. Lows will remain seasonably warm (70-74F). Updates are out. /DC/ && .DISCUSSION... Issued at 315 PM CDT Fri Aug 21 2026 Through Saturday: A frontal boundary will sag slowly southward toward the coast and help to focus scattered diurnally driven storms for the remainder of the afternoon and into the early evening over the southern half of the area. Given how hot and unstable the boundary layer conditions are, steep low level lapse rates are supporting microburst winds (e.g., 58 mph gust at TVR just now), and have continued to message for a slight severe weather risk this afternoon/evening. This threat may shift into northwest portions of the area Saturday afternoon as stronger mid level flow potentially brings organized convection, so stay tuned for additional severe weather messaging. Of course the dangerous heat threat continues as well and have issued an additional heat advisory for Saturday. The heat will gradually become more focused over southwest portions of the area, and have adjusted our messaging to reflect this. Sunday through next week: Global model guidance indicate that a northwest flow pattern will evolve and persist through the remainder of the forecast. A NW-SE oriented thermal gradient will support the greatest heat stress over southwest portions of the forecast area, but this doesn't appear it will be more than a limited to elevated dangerous heat situation. This pattern would continue to support an occasional MCS threat, but timing details are very uncertain, and overall rain chances are not great in the mean. Unfortunately for those needing rainfall, there are no strong signals for significant rainfall at this point aside from a gradual uptick in rain chances as we go later into next week. All global model ensembles point to dry anomalies. Given the continued vegetative stress, the forecast area will become more vulnerable to fire danger should wind/RH thresholds be met. As of now the weather pattern isn't supporting this, but all fire related interests should monitor closely. /EC/ && .AVIATION... (00Z TAFS) Issued at 919 PM CDT Fri Aug 21 2026 VFR flight conditions will prevail through the period. Winds will be light and variable tonight and gradually shifting northerly but remaining light (sustained/gusts under 10mph) into Saturday. /DC/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 73 100 74 99 / 0 0 10 10 Meridian 73 99 73 98 / 10 0 10 10 Vicksburg 73 100 73 98 / 0 10 10 10 Hattiesburg 74 99 74 99 / 40 0 0 10 Natchez 74 101 75 99 / 10 0 0 10 Greenville 73 99 73 98 / 0 10 20 10 Greenwood 72 98 72 97 / 0 10 10 10 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...Heat Advisory from 11 AM to 8 PM CDT Saturday for MSZ018-019-025- 034>036-040>043-047>049-053>055-059>064-072. LA...Heat Advisory from 11 AM to 8 PM CDT Saturday for LAZ007>009-015- 016-023>026. AR...Heat Advisory from 11 AM to 8 PM CDT Saturday for ARZ074-075. && $$ DC/EC/DC