textproduct: Jackson

KEY MESSAGES

- Isolated severe storms are possible in the northwest Tuesday evening.

- Heat and humidity more typical of early summer can be expected along with increasing thunderstorm chances this week into the weekend.

MESOSCALE UPDATE

Issued at 854 PM CDT Mon May 18 2026

Earlier isolated showers and thunderstorm activity has ended for the evening. Moisture could allow for some patchy fog to develop in southeast Mississippi in the early morning, but dense fog is not expected. /NF/

DISCUSSION

Issued at 219 PM CDT Mon May 18 2026

Rest of the week into weekend (Tuesday through Sunday)...

Longwave trough will be ejecting into Canada and Hudson Bay region. Persistent summertime pattern of seasonable warmth (4F to 8F above and highs in 88F to 92F) and moisture (forecasts of 1.5 to 1.9 inches) will be the norm. Diurnal shower and thunderstorm activity will be a concern ahead of a few perturbations in the southwesterly flow (20 to 55 percent) and increased heat and humidity. With some steep lapse rates (vertical totals near 27C to 29C), some strong to isolated severe storms remain possible Tuesday and into mid week. There is anticipated of afternoon development in the Plains should sink southeast into the Ozarks in the evening and make it into the area by late afternoon into early evening. Storm mode is a question but even a southeast traversing cold pool could initiate some strong to isolated severe thunderstorm activity into Tuesday evening. While there could be some diurnal activity between 3-5PM, the concern for severe storms will be mainly after 6PM and last until just after midnight. The ongoing HWO graphic remains valid, but the timing has been slowed down into the evening to just after midnight (6PM Tuesday through 2AM Wednesday). Deep flow/bulk shear will be light (15-25kts) and variable and storm organization will need to be in tandem to the southwesterly low level flow. This could hinder any southeastward propagating MCS, which is alluded to in some convective allowing model (CAMs) output. With generally southerly to southwesterly flow in the low levels, cold pools may eventually get out of balanced and more cold pool dominant, decreasing the severe potential closer to Interstate 55 and central portions of the area closer to or just after midnight. Damaging wind gusts and hail remain the main concerns.

As a stronger wave swings into the Great Lakes and surface low ejects into eastern Canada (995mb to 1000mb), front will shift south southeast towards the Gulf states. Several perturbations will enhance upper diffluence, increasing ascent and moisture advection. This will drive higher coverage of rain and storms (45 to 90 percent Wednesday and Thursday). High temperatures will be seasonable (mid to upper 80s Wednesday to low to mid 80s rest of the week) with lows less seasonable, from 8F to 12F above (upper 60s to low 70s). With less seasonable temperatures, humidity and lapse rates, some stronger storms are likely and marginally severe storms remain possible. Mid to deep layer bulk shear will remain sufficient (around 30kts), with low level shear around 15-25kts. This will keep potential marginally severe concerns through the remainder of the work week (Wednesday through Friday). Rain totals for the week will be around a couple of inches (1 to 3 inches), which will help lessen some long term drought concerns. Large scale synoptic pattern (i.e. southwesterly return flow, warm advection, high PWs near 2 inches) will persist, keeping rain chances high late week into the weekend (70 to 90 percent Friday through Sunday). Some low end severe potential cannot be ruled out, but lower severe probs and less heat and shear juxtaposed will keep mention of anything in HWO on a day-to-day basis, each day dependent on previous day's storm evolution. Rain totals will add up (additional one to three inches, with storm total rain through the weekend of 4 to 6 inches), continuing improvements to long term drought concerns. /DC/

AVIATION

(06Z TAFS) Issued at 1253 AM CDT Tue May 19 2026

Latest satellite imagery showed an area of stratus over the southeast that wl result in MVFR/IFR cigs across the south and cntrl TAF sites as it expands through 12Z. These lower flight conditions wl improve to VFR by 16Z. After 16Z VFR conditions wl prevail areawide until SHRA/TSRA move into the nw and spread over the cntrl TAF sites toward the end of the TAF period. /22/

PRELIMINARY POINT TEMPS/POPS

Jackson 71 86 69 85 / 60 60 60 70 Meridian 70 88 68 86 / 20 30 40 50 Vicksburg 70 85 69 84 / 70 80 70 70 Hattiesburg 69 88 69 87 / 10 50 20 50 Natchez 71 86 70 85 / 60 80 70 70 Greenville 71 83 68 82 / 80 90 70 80 Greenwood 71 85 68 84 / 70 90 70 80

JAN WATCHES/WARNINGS/ADVISORIES

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