textproduct: Jackson

KEY MESSAGES

- There is a Slight 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.

- Additional rounds of storms could impact the area later in the week.

DISCUSSION

Issued at 313 PM CDT Mon Apr 27 2026

Through Tonight...

Near term guidance shows a <1000mb low over the Central Plains shifting off towards the northeast. As this low tracks east, the associated cold front will begin to track south towards the southeast CONUS. With southerly moisture flow over our area heading into the late afternoon and evening, convection will start firing off along and ahead of the front with some of this activity reaching our northern most zones. During the evening and overnight period as the cold front approaches our CWA, strong to isolated severe storms will be possible for areas mainly north of I-20.

A few adjustments were made to the severe graphic for today and the "Marginal" risk (1 out of 5) has been extended southward. This was due to local CAM guidance showing initiation of storms further south. In coordination with the Storm Prediction Center (SPC), a "Slight" risk (2 out of 5) has been introduced for areas along and north of Hwy 82 including portions of southeast AR. Despite the adjustments made to the graphic, the primary hazards heading into tonight will be damaging wind gusts, large hail, and a few tornadoes. Timing for storms looks to be between 3PM this afternoon to 1AM early Tuesday morning. /CR/

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.

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. A "Limited" threat for heavy rainfall has been introduced for portions of Southeast Arkansas and North Mississippi for Tuesday night. Rainfall totals will be between 2-4 inches which could lead to some localized flash flooding, particularly in low lying and urban areas.

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. With that in mind, model guidance is showing higher probabilities of strong organized lines of storms to race east across the area into the evening/overnight period. In coordination with SPC, an "Enhanced" risk for severe storms has been introduced mainly for areas along and north of I-20, including portions of Southeast AR, and several of our Northeast LA parishes.

Wednesday Through Monday...

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.

Looking ahead into early next week, guidance is starting to show a 1020mb sfc high over the Southern Plains shifting towards our forecast area. This will allow for quiet weather conditions to persist over the region with daytime highs peaking in the upper 70s. /CR/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 69 87 67 83 / 40 60 60 60 Meridian 65 86 65 85 / 40 70 70 50 Vicksburg 70 87 67 84 / 40 60 60 60 Hattiesburg 66 89 67 88 / 10 40 30 30 Natchez 69 90 69 86 / 20 50 30 50 Greenville 69 83 68 78 / 70 80 90 50 Greenwood 68 84 67 81 / 70 80 90 50

JAN WATCHES/WARNINGS/ADVISORIES

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