Area Forecast Discussion

KEY MESSAGES

Updated at 856 PM CDT Sun Apr 19 2026

- An unsettled pattern will develop next weekend bringing additional chances for rain and storms.

NEAR TERM

(Today) Issued at 236 AM CDT Mon Apr 20 2026

Under surface high pressure clear skies and calm winds have prevailed across the TN Valley. This has created an ideal scenario for radiational cooling and temps have dropped into the mid 30s to low 40s across the area as of about 2 AM. With the cooler temps in place through sunrise, be sure to grab a jacket before heading out the door.

Through the day, surface high pressure will build over the TN Valley maintaining clear skies. Without any significant airmass change, temps will be slow to warm today, only warming to the mid 70s by the afternoon. Dew points will be slower to rebound resulting in min RH around 30% this afternoon. Fortunately winds will be light enough to dissuade any fire weather concerns.

SHORT TERM

(Monday night through Wednesday) Issued at 856 PM CDT Sun Apr 19 2026

Through the short term, surface high pressure will shift to east towards the mid Atlantic. This will locally induce a return flow pattern and jump start a WAA regime through the remainder of the week. Highs will warm to the low 80s by Wednesday with dew points rebounding into the high 40s.

Aloft, a more zonal pattern will develop in the central CONUS ahead of a building ridge in the southern Plains. Come Wednesday, a shortwave will slide along the leading edge of the ridge and across the Gulf coast. Cloud cover will increase Tuesday night in association with this feature however the shortwave will be too far to our south to illicit any additional impacts. As the ridge aloft builds and pushes the shortwave SE, NW flow aloft will redevelop, aiding in clearing skies by mid day Wednesday. Clear and calm conditions will return through the remainder of the day on Wednesday making for a pleasant late spring day ahead of a pattern shift in the long term forecast.

LONG TERM

(Wednesday night through Sunday) Issued at 856 PM CDT Sun Apr 19 2026

Upper level ridging begins to move into the Southeast during the second half of the work week. With sfc high pressure located across GA/SC, southerly flow will advect in a warm and moist airmass into the Tennessee Valley. Locally, this results in a gradual warming trend in temperatures, but also a much more noticeable increase in dewpoints. Afternoon highs Thursday and Friday rise into the mid 80s with dewpoints increasing from the lower 50s on Thursday to lower 60s by Friday evening. The dry pattern comes to an end by this weekend as troughing to our west shifts eastward allowing for several shortwaves to ripple through the local forecast area. The first of these disturbances arrives Friday evening/Saturday morning, which will bring a medium chance (45-65%) of showers and thunderstorms to the area. A more substantial system moves through this weekend and will be something to keep an eye on for severe storms. Joint probabilities of shear greater than 30 knots and CAPE exceeding 1000 J/kg have increased to around 30 percent. Various machine learning algorithms also show low probabilities of severe storms. At this time it is too early to pin down an exact timeframe of the most likely period for showers and thunderstorms will be 6-7 days out. However, it is April and this is typically one of our most active months for severe storms. Check back for updates as details for the weekend become more clear.

AVIATION

(12Z TAFS) Issued at 642 AM CDT Mon Apr 20 2026

VFR/SKC conditions will persist at the HSV/MSL terminals for much of the upcoming forecast period, although a few fair-weather Cu may develop from late this morning through the aftn hours. Sfc winds will range from WNW at 5-10 kts during the daylight hours to lgt/vrbl-calm at night, and although conditions will indeed be favorable for the development of patchy BR/FG btwn 8-12Z Tuesday, we will not introduce vsby reductions in the TAFs at this point.

HUN WATCHES / WARNINGS / ADVISORIES

AL...None. TN...None.