textproduct: Jackson

KEY MESSAGES

- There is a Marginal risk for severe weather over southeast Arkansas and north central Mississippi late this afternoon into tonight.

- A more significant severe weather threat exists late Tuesday into Tuesday night, and additional rounds of storms could impact the area later in the week.

DISCUSSION

Issued at 252 AM CDT Mon Apr 27 2026

Through Tonight: It will be warm and breezy today with the potential for isolated severe storms in our north tonight. Early morning satellite imagery/RAP analysis showed a series of subtle disturbances helping fire off convection well to our north over the central Plains and mid Mississippi valley. Shortwave ridging aloft was noted over our CWA emanating from a large high centered over Mexico. Latest surface analysis had a <1000mb low over the central Plains with a >1018mb ridge nosing west across the Gulf coast states. The pressure gradient between these two features will result in a gusty south wind around 25mph across our CWA. This will help result in near record highs this afternoon at a few climate sites. The site at greatest risk of tying or breaking a record is at the Tallulah-Vicksburg airport where the current record high for the date is 90F set back in 2025. This warm low level flow and ridging aloft looks to keep our airmass capped much of the day but daytime heating of our moist airmass will likely lead to a few showers and thunderstorms by late morning and early afternoon. By late afternoon and evening though, the surface low will have moved off to the northeast with convection firing off along and ahead of its associated cold front. Some of this activity may drop into our northern most zones. During the evening and overnight as the cold front approaches isolated severe storms capable of damaging wind gusts and hail to the size of quarters will be possible; generally along our Highway 82 corridor. /22/

Tuesday through Tuesday night: Tuesday remains the most likely day over the next week for the potential for widespread, perhaps significant severe weather with the risk being generally greater the further north you go. While the best juxtaposition of instability and shear will remain to our north nearer the departing surface low late Monday, the remnant composite outflow/cold frontal boundary will likely be draped from west to east across the Lower MS Valley region as we head into Tuesday. The general synoptic pattern will result in split flow aloft which favor effective synoptic scale divergence. At the same time, a stout, embedded shortwave will emerge out of Mexico into south Texas, arriving across the Texarkana region by midday. This will likely trigger widespread thunderstorm growth progressively eastward as it encounters a weakly capped, very moist boundary layer below. Low level shear will remain modest (0-1 KM storm relative helicity (SRH) < 150 M^2/S^2) in the absence of substantial surface pressure falls/cyclogenesis but there is some probability that should storms grow upscale quickly to our west before rushing eastward in our direction as an evolving mesoscale convective system (MCS) while in the presence of a favorably positioned/stalled frontal boundary, that a well-defined MCV could locally back surface winds in its proximity. Should this happen, both discrete storms directly ahead of the complex within the environment of improved low level jet (LLJ) velocities as well as any circulations that are embedded within surging line segments could produce brief tornadoes.

The parameter space for large hail and damaging winds are more clearly defined. Mixed layer convective available potential energy (ML-CAPE) will likely exceed 2,000 J/KG for much of the area with locally higher values to 2,500 J/KG where moisture pooling is favored in the vicinity of the boundary. Deep layer shear will be adequate for all severe modes as 50-55 kts of 0-6 km bulk shear likely becomes realized by Tuesday evening into the overnight period. Lapse rates aloft won't be particularly impressive and storm mode favoring upscale growth puts further question marks on hail potential, but particularly in "younger" cells that may develop ahead of potential MCS/organized clusters, severe hail (1"+) will be possible.

In addition, storm motions will likely be primarily west to east which will parallel the stalled boundary. With precipitable water values (PWATs) above 1.8", storm motions not particularly fast for our area this time of year (generally less than 40 kt forward motion), and the tendency for storms to move over the same areas, localized flash flooding appears increasingly possible. It's likely hazard graphics addressing this risk will be needed by later today-- uncertainty in precise location of this risk as well as its marginal nature (drought conditions coupled with the potential risk areas, likely north of I-20 which missed most recent heavier rains) will preclude issuance of a flash flood hazard product with this forecast cycle.

Overall, the exact placement and severity of the primary storm axis remains in flux and will be modulated by the eventual, precise location of the stalled boundary as well as the stormscale interactions or upscale growth we observe to our west during the day on Tuesday.This continues to produce an unusually large degree of uncertainty and as such the forecast may be subject to larger day- today changes than typical as we get closer to the event. The ceiling remains fairly high particularly in terms of the risk for numerous occurrences of straight lined wind damage, which has supported the "SLIGHT" (2 out of 5) risk for severe storms for much of the area. Should the higher-end possibilities continue to appear likely, upgrades for some of the area could be possible.

Wednesday through Friday night: Following storms Tuesday, the boundary will likely sink toward the Gulf Coast during the day Wednesday, and by Thursday will result in lowered humidity and an at least temporary end to the near daily strong/severe storm risk. The pattern does remain active, however, and rain and storms will continue to be possible moving into later this week. Being on the drier side of the boundary should keep this activity below severe limits, though.

By next weekend, a potent southern stream shortwave will likely bring our next shot at strong to potentially severe storms. The major caveat with this activity will be the surface boundary and how far inland the developing surface cyclone can force it. With little space between the departing long wave trough and the incoming shortwave, the warm front will be facing a tug-of-war scenario as continental dry air and a surface high not far away, perhaps as near as northern Georgia, attempting to remain entrenched squares off against the southerly mass recovery attempts of the incoming surface cyclone/frontal wave. The demarcation between noisy and wet weather versus strong to severe storms will likely be defined by this progress an guidance differs greatly on how that may play out. For now, the most likely scenario would be for some stronger storm risk across our southernmost areas. This situation should be monitored carefully particularly for folks along or south of the I-20 corridor. /LP/

AVIATION

(18Z TAFS) Issued at 1237 PM CDT Mon Apr 27 2026

As of 1737Z, all TAF sites are reporting VFR conditions with GLH currently reporting MVFR ceilings. A gusty southerly wind 18-24 kts will continue through this afternoon and will subside after 00Z Tuesday. VFR ceilings will prevail across the area through the evening with ceilings deteriorating after 10Z Tuesday. Isolated -SHRA/TSRA will be possible during the afternoon but scattered -TSRA wl spread over the northern TAF sites this evening and then over the central TAF sites after 06Z. Poor flying conditions will prevail across multiple TAF sites heading into the overnight period due to widespread -TSRA. /CR/

PRELIMINARY POINT TEMPS/POPS

Jackson 68 87 67 84 / 40 60 60 60 Meridian 65 86 64 84 / 30 60 60 50 Vicksburg 69 87 67 83 / 40 50 60 60 Hattiesburg 66 88 67 88 / 10 20 30 40 Natchez 69 90 69 87 / 10 40 20 50 Greenville 69 84 68 79 / 70 70 90 50 Greenwood 68 86 67 81 / 70 70 90 50

JAN WATCHES/WARNINGS/ADVISORIES

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