textproduct: Jackson

KEY MESSAGES

- Dangerous levels of heat stress will build back in areawide through early next week before a front brings drier air and more pleasant temperatures late next week.

MESOSCALE UPDATE

Issued at 753 AM CDT Sun Sep 20 2026

Forecast remains on track with the ridge visible on satellite this morning. Our region will remain one of the hottest in the nation again today with temperatures in the upper 90s to near 100 (compare to an average high of 87 this time of year) Records could once again be tied/broken. While most the area should remain dry today, increased moisture in the far southeast will leave a low chance (15%) for rain today along the I-59 corridor. /SAS/

DISCUSSION

Issued at 1210 AM CDT Sun Sep 20 2026

Another hot day is on tap for today as an H590 ridge continues to prevail over the area. Highs will be in the mid 90s to around 100 across the area with heat indices ranging from 100-105. Expect mostly dry conditions, but there could be a stray shower in the southeast. /15/

Monday through next weekend...

The anomalous ridge responsible for recent record breaking heat begins to break down early next week with the approach of a shortwave trough. There is a subtle moisture return in response to this, which will increase dewpoints back into the low 70s. This should both increase dangerous heat as well as rain chances beginning Monday and persisting through Tuesday. Heat indices will range from 100-105+, with the hottest temperatures west of I-55. An elevated heat graphic continues to be advertised. Would not rule out a heat advisory for Monday and possibly Tuesday. Further east, where low (20-30%) rain chances are focused, indices are likely to remain below criteria (105), but there will still be a limited heat threat. Isolated to scattered showers and thunderstorms, in perhaps the first sign of the cool season, will not be strictly diurnal, and should continue overnight ahead of a slow moving frontal boundary. Since synoptic forcing is still weak, this frontal boundary will slowly sag south over the course of Wednesday and into Thursday as the shortwave rounds the midlevel high. There is some difference among the guidance regarding the timing of the main jet energy associated with the shortwave, but there is good agreement, and it makes meteorological sense, that shortwave ridging will be reinforced in its wake late next week into the weekend. Dry conditions will return with a continuation of above normal temperatures. /SAS/

AVIATION

(12Z TAFS) Issued at 611 AM CDT Sun Sep 20 2026

VFR conditions will prevail through the TAF period. /22/

PRELIMINARY POINT TEMPS/POPS

Jackson 98 74 97 72 / 0 0 20 20 Meridian 98 72 97 71 / 10 10 30 20 Vicksburg 97 74 97 72 / 0 0 20 20 Hattiesburg 97 73 96 71 / 10 10 40 10 Natchez 98 74 97 73 / 0 0 20 10 Greenville 99 75 99 73 / 0 0 20 20 Greenwood 99 73 99 71 / 0 0 20 20

JAN WATCHES/WARNINGS/ADVISORIES

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