textproduct: Jackson

KEY MESSAGES

- Additional periods of heavy rainfall and flash flooding will be possible today.

DISCUSSION

Issued at 138 PM CDT Thu May 28 2026

Through mid next week (Today through next Tuesday)...

Today into tonight: Perturbed flow/vorticity will drive increased moist ascent and deep moisture (1.75 to 2.1 inch precipitable water) into the southern areas this morning. There is continued indications of a mesoscale convective vortex (MCV) that will lift northward somewhere near the ArkLaTex region, potentially west of the MS River. This will drive a stronger low-level jet, ascent and convergence on a mesoscale level. This will be difficult to pin down exact areas but our southwest areas have the best chances of seeing enhanced rainfall rates due to this feature. Light backbuilding flow and some enhanced cloud bearing flow (up to 20kts) will enhance rainfall totals in these areas. Based on that, we decided to make some local adjustments to the HWO graphics to hone in to a more refined zone of potential higher rainfall rates, totals and flash flood concerns. This will generally be in the Delta counties of west, southwest and southern MS, southeast AR and northeast LA. Convective allowing models (CAMs) support this idea. This HWO graphic will now be refined to just Thursday and will be on a day-to-day basis but the current one will not include Friday.

Afternoon convection will be generally scattered in coverage (45 to 65 percent). Highs will remain seasonable (mid 80s), with seasonably warm lows this morning and again tonight (upper 60s to low 70s). HREF probability match mean (PMMs) indicate another round of neighborhood probs (10 percent) for receiving in excess of 3 inches, with some higher totals in the HREF maximums. In addition, there are some HREF dense fog probs both this morning and again tonight, but confidence isn't high enough to add any mention in the HWO but only in the weather grids at this time.

Friday through next Wednesday: As upper low over TX/OK Panhandle lifts north, southerly flow will remain established but lighter through the week. The region will remain in a longwave quasi- omega block pattern into late week (upper low caught over the Pacific states and developing longwave trough over the northeast states into eastern Canada). However, this synoptic pattern doesn't look as established as a typical omega block, with strong subtropical ridging established over the western Atlantic extending westward into the FL Peninsula. On the eastern periphery of the western portion of the quasi-omega block the perturbed energy/vort max will lift northward but some of the tail end of the trough axis will slowly shift east across the region Friday. This will keep light return flow, deep moisture and light backbuilding flow into Friday. Rain coverage will remain high Friday (45 to 80 percent daily) and becoming focused east of MS River corridor Friday.

As the upper low lifts and trough axis shifts east across the Mid South to Mid MS Valley into the weekend, shortwave ridging and westerly flow will lock in, leading to less moist Gulf influence and more scattered rain and storm coverage (35 to 65 percent Saturday and Sunday). Highs remain seasonably cool this weekend (low to upper 80s) while generally seasonably warm lows (upper 60s to low 70s). Longer range pattern consists of surface high diving into the Great Lakes and eventual drying front from the north. However trends have slowed, with most relief in rain coverage becoming more scattered next Monday to shifting southward and isolated to scattered next Tuesday to Wednesday (20 to 40 percent). Continued seasonable cool highs and less seasonably warm lows will be the norm through the middle of next week. /DC/

AVIATION

(18Z TAFS) Issued at 1230 PM CDT Thu May 28 2026

Another round of showers/thunderstorms are expected to make their way through the region today and may bring short-lived MVFR ceilings. Once showers and thunderstorms die down around sunset expect an anchoring of those lowered cloud decks and brief periods of fog along our southern corridor. Tomorrow may bring another smattering of thunderstorms/showers but less active than today, which will bring the same conditions as today should that come to fruition across the CWA./OAJ/

PRELIMINARY POINT TEMPS/POPS

Jackson 70 85 69 87 / 20 70 40 40 Meridian 70 84 69 87 / 20 50 40 50 Vicksburg 69 85 70 88 / 20 50 30 30 Hattiesburg 70 85 69 88 / 20 50 30 40 Natchez 70 86 71 89 / 20 50 20 20 Greenville 70 84 70 87 / 60 50 20 20 Greenwood 70 84 70 87 / 50 60 40 40

JAN WATCHES/WARNINGS/ADVISORIES

MS...None. LA...None. AR...None.