textproduct: Jackson

KEY MESSAGES

- There will be a marginal risk for a few brief weak tornadoes over southeast to eastern portions of the area early Friday morning.

- The potential for heavy rainfall and flooding will continue through the weekend, peaking Sunday and Monday.

- We will be monitoring the potential for additional heavy rainfall and flash flooding next week.

DISCUSSION

Issued at 345 PM CDT Thu May 21 2026

In the near term, the next in a series of weak MCVs has combined with a very moist airmass (precipitable water near 2 inches and surface dewpoints in the lower 70s) and peak heating to initiate another round of showers/storms with intense rainfall rates this afternoon. Following days of heavy rainfall, some locations are becoming more flood prone and sensitive to additional heavy rainfall, and so have continued the limited flash flood threat messaging in our HWO graphics. Flash flood threats will tend to peak during the day into the evening, but persistent convergent zones that focus intense rainfall rates for long durations could develop at just about anytime.

In addition, An MCV forecast to cross the area late tonight into Friday appears it will enhance the low level shear/vorticity in a very moist boundary layer making any convective updrafts more prone to spinning up weak and brief tornadoes. After assessment of the near term guidance low level shear parameters and convective evolution, it appears that locations along the I-59 corridor will have peak tornado threat during the 4 am to 10 am time frame. An additional limited flash flood threat will accompany this MCV as well.

Looking ahead, an unusually long duration of wet weather will continue for the foreseeable future as a large and persistent trough to ridge longwave pattern remains anchored over the CONUS. This will continue to bring our region a steady stream of subtropical moisture with seasonably high precipitable water values, and multiple upper level perturbations that will provide lift and help initiate additional rounds of convective rainfall. Once we get to about Sunday, a greater threat for flash flooding should evolve as a more favorable set-up and couple upper level jet interaction may team up with the very moist air to bring a more widespread heavy rainfall threat. As of now this appears it will be over mainly western/southern portions of the area and have included an "elevated" flood threat in this area.

Otherwise, it appears the thermodynamic/shear profiles will not be particularly favorable for severe weather concerns given the deep moisture and influence from the southeast CONUS ridge, but as is the case in the near term, we'll need to monitor for marginal tornado risks given the potential for enhanced low level shear in the very moist air. As previously mentioned, it's difficult to find an end to this wet pattern in the guidance through most of the remainder of the month. /EC/

AVIATION

(18Z TAFS) Issued at 110 PM CDT Thu May 21 2026

A mix of VFR/MVFR/IFR conditions will be possible at all sites through the TAF period as rain and low ceilings impact the area. Brief periods of lowered categories will be possible during bouts of heavier rainfall./KP/

PRELIMINARY POINT TEMPS/POPS

Jackson 68 80 68 85 / 90 80 60 70 Meridian 68 81 68 85 / 70 90 80 80 Vicksburg 67 81 68 85 / 90 70 40 70 Hattiesburg 70 82 69 85 / 60 90 70 90 Natchez 68 81 69 85 / 90 70 40 80 Greenville 67 81 67 84 / 90 70 40 60 Greenwood 67 80 67 85 / 80 90 70 60

JAN WATCHES/WARNINGS/ADVISORIES

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