023 FXUS64 KHUN 150052 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 752 PM CDT Thu Jul 14 2022 ...New NEAR TERM... .NEAR TERM... (Tonight) Issued at 752 PM CDT Thu Jul 14 2022 The stationary surface boundary is located just to the south of the forecast area and is forecast to stay to the south throughout the overnight hours. The boundary is not hard to pick out with the dewpoint in Gadsden of 73 degrees and the dewpoint in Albertville at 59 degrees. Dewpoints are lower across the Tennessee Valley with most locations in the low to mid 60s with a few upper 50 readings. Winds are light and from the north. Water vapor imagery and RAP upper air analysis indicates a positively tilted trough located just to the north and west of the area. Water vapor imagery depicts extremely dry air aloft along the western periphery of the trough stretching from Great Lakes southwestward into the southern Plains. The atmosphere is already dry across the Tennessee Valley and dry air will continue to advect into the area as the upper trough axis shifts to the east of the area. PW values will drop down to around 1 inch later tonight. These values are near the minimum for mid- July PW climatology. Overall, not expecting any precipitation overnight. The dry airmass should allow for temperatures to drop down into the mid to upper 60s for most locations by Friday morning. Also, with the dry atmosphere, do not expect any fog formation overnight. && .SHORT TERM... (Friday through Sunday) Issued at 122 PM CDT Thu Jul 14 2022 On Friday, an upper level trough across the East Coast will gradually lift to the northeast. During the short term forecast period, the Tennessee Valley will be situated between the aformentioned trough and an upper level ridge across the Western Plains. As a result, a dry airmass will remain locked in place making for a dry end of the work week and through the first half of the weekend. Afternoon highs each day will be in the low to mid 90s with overnight lows in the upper 60s to lower 70s. Better moisture return on Sunday will allow for some isolated afternoon thunderstorms to develop. && .LONG TERM... (Monday through Thursday) Issued at 122 PM CDT Thu Jul 14 2022 By the start of next week, the upper level pattern becomes more zonal across the eastern third of the CONUS with the upper ridge situated over the Rockies. A shortwave along the eastern edge of the ridge drops down towards the Tennessee Valley with an associated front to its southwest. This will result in widespread showers and thunderstorms Mon afternoon through at least Tuesday morning. At this time, severe storm chances appear quite low given low shear. However, with PW values approaching 2 inches, expect any shower or storm to produce locally heavy rainfall, which may result in localized flooding. Model guidance still varies on the forward speed of the front, therefore have kept rain chances in the forecast through Tuesday evening. Starting midweek, a more typical summertime pattern sets up. Afternoon highs in the low to mid 90s with chances for diurnally driven thunderstorms. Overnight lows will be in the low to mid 70s. Due to the higher humidity, heat index values may reach the low 100s, but at this time they should remain below heat advisory criteria. && .AVIATION... (00Z TAFS) Issued at 655 PM CDT Thu Jul 14 2022 VFR conditions will continue through the TAF period with light winds and clear skies. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...MA SHORT TERM....GH LONG TERM....GH AVIATION...25