Area Forecast Discussion (AFD)
Issued by Huntsville, AL (HUN)
256 FXUS64 KHUN 180149 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 849 PM CDT Mon Sep 17 2018 .NEAR TERM...(Tonight) Issued at 750 PM CDT Mon Sep 17 2018 The remnants of Florence continue to advect ENE away from the TN Valley this evening, centered over WV as of this writing. One final spoke of high clouds rotating around the Wrn periphery of the decaying system is now pushing Swrd into NW AL. Sky grids have been updated accordingly for tonight given the latest Nighttime Microphysics RGB imagery showing this trend. The impact these clouds will have on the patchy fog development across the area should be to lessen an already low potential for fog, but will monitor this trend and update the forecast as necessary (with some lower clouds noted along the TN/KY border upstream if they hold together). Otherwise, dry and mild wx conditions are expected overnight with morning lows falling into the upper 60s by sunrise. No additional changes were warranted to the current forecast other than tweaking sky grids to follow more in line with observational trends. .SHORT TERM...(Tuesday through Wednesday) Issued at 343 PM CDT Mon Sep 17 2018 With the departure of the tropical system, dry and very warm to hot conditions continue through the midweek. With more sun than clouds, even with a light northerly flow, high temperatures both days should rise into the upper 80s to lower 90s. Have inched temperatures to the mid 90s for Wednesday, as upper ridging builds over the region from the southwest. More unseasonably warm nights with lows in the mid 60s to around 70 are expected. For reference, normal highs this time of year are in the low/mid 80s and lows in the lower 60s. Even with the daytime warmth, enough moisture left over Tuesday night could bring more patchy fog formation during the late night. Given uncertainly on coverage/density, left it as patchy this issuance. .LONG TERM...(Wednesday night through Sunday) Issued at 343 PM CDT Mon Sep 17 2018 One more day of very warm/hot and dry weather continues on Thursday, thanks to strong upper ridging in place across the southeastern CONUS. Highs should warm into the low 90s, with a few mid 90s very possible, especially across northern Alabama west of the I-65 corridor. The upper ridge will shift east of the region for the upcoming weekend, with weak troughing edging closer. E-SE winds on Thursday will become more southerly during Friday and the weekend. This will bring additional and deeper lower level moisture across the region. This moisture and accompanied daytime heating produced instability will return chances of showers and thunderstorms to the forecast - just in time for the weekend. The deeper moisture, along with more clouds than sun should result in slightly cooler temperatures going into the weekend. Stayed on a diurnal trend, with higher rain chances in the day and lesser at night for Saturday and Sunday. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 654 PM CDT Mon Sep 17 2018 VFR conditions will prevail at both terminals thru the period with the exception of some MVFR fog shortly before/around daybreak. Patchy fog will dissipate by 18/14Z, with a SCT deck of clouds developing AOA 4kft by midday tomorrow, lingering thru the end of the TAF period tomorrow evening. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && $$ NEAR TERM...12 SHORT TERM...RSB LONG TERM...RSB AVIATION...12 For more information please visit our website at weather.gov/huntsville.