Sewanee, TN 37383 Weather

Key Messages

Updated at 858 PM CDT Wed Oct 21 2026

- Very low afternoon relative humidity values are below 25% expected today.

Near Term

(Rest of Today and Tonight) Issued at 858 AM CDT Thu Oct 22 2026

Much drier air in place below 700 mb in 7 AM soundings this morning than yesterday. Strong upper level ridging is centered over Texas into the western Great Lakes region. However, the eastern edge of this upper level ridge is pushing into NW Alabama. With sunny skies expected and the strong upper level ridging building slowly east, highs will likely top out above NBM(based on the trends over the last few days). Thus, raised high temperatures into the 76 to 81 degree range in NW Alabama. Further east, highs in the mid to mid/upper 70s are expected.

7 AM soundings indicate extremely dry air in place between 700 mb and 850 mb. There also is some dry air aloft just above the surface, which we will likely tap into when temperatures climb to between 65 and 70 degrees. The strongest mixing is more likely to occur in the afternoon hours, when the much drier layer between 850 mb and 700 mb is mixed up to. This will drop relative humidity values to between 20 and 25 percent.

Clear skies will continue tonight. Light winds are expected in lower elevations, however, winds may stay around 5 or 6 mph in higher elevations (925 mb winds pick up to between 10 and 20 knots). This should setup a good ridge/valley split in low temperatures with lower elevation dropping into the lower 40s and higher elevations only dropping into the 45 to 50 degree range.

Short Term

(Friday through Sunday) Issued at 858 AM CDT Thu Oct 22 2026

Friday may end up being much drier in the afternoon as well based on forecast soundings due to mixing in the late morning and afternoon hours. For now, keeping with Conshort guidance (slightly below NBM for dewpoints). However, this may need to be lowered further in future updates. The center of the upper level ridge moves further east into SW Arkansas on Friday. Expect highs to again be slightly above guidance (especially in NW AL). Highs will likely climb into the upper 70s at least in NW AL.

Saturday into Sunday, guidance is trending further south with the location of the weak upper low that shifts SSE along the eastern seaboard. At the same time newer guidance continues to build the very amplified upper ridge further east into the northern Gulf of America extending northward into the central Great Lakes region. Expect NBM and models are not really picking up on how warm it will be underneath the upper ridge. Though low level forecast winds do indicate that a dry wedge front may push into the area from the east. This may counter the upper ridge concerning higher afternoon temperatures. However, the strength of the ridge may still allow temperatures to be higher than current forecast guidance. Low level moisture will likely increase, but significant afternoon mixing still looks like a good bet both Saturday and Sunday.

Long Term

(Sunday night through Wednesday) Issued at 955 PM CDT Wed Oct 21 2026

The upper ridge will breaking down Sunday night into Monday/Tuesday as the southwest U.S. ejects into the Plains and OH Valley. The southern tail of this wave will move through Tuesday into Wednesday, but the airmass will too dry to support precipitation. The surface ridge will remain in place, but pressures will be falling as it weakens. Temperatures in upper 60s to lower 70s on Monday under the influence of the wedging ridge will warm into the lower to middle 70s Tuesday and Wednesday. Lows will be in the lower to middle 40s over the weekend into Monday morning, warming into the middle 40s to around 50 by Wednesday and Thursday mornings.