Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
005 FXUS64 KMRX 030546 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 146 AM EDT Sun Aug 3 2025 ...New DISCUSSION, AVIATION... .DISCUSSION... Issued at 133 AM EDT Sun Aug 3 2025 Key Messages: 1. Daily rain chances will continue through the week as a trough remains parked over the region. 2. Below normal temperatures expected through mid week. Discussion: The inverted surface trough that was near the spine of the Appalachians on Saturday will shift westward as the New England ridge builds southward. The trough axis will be positioned closer to the Cumberland Plateau by this afternoon, and this will be the focus for much of the shower activity today. Instability remains quite limited, so thunderstorms should be isolated, and NBM thunder probs will be cut back. PW values remain in the 1.7-1.8 inch range, and with weak low to midlevel flow, there may be slow-moving storms that cause some isolated flooding problems, similar to the past few days. On Monday a 850 mb low will be over AL, with a 500-300 mb trough over MO/AR. This will keep a good flow of Gulf moisture feeding into the TN Valley in the low to midlevels. Showers across AL/GA in the first half of the day should spread northward into our area by the afternoon and continue through the evening, in conjunction with a northward moving jet streak on the east wide of the upper trough. Flooding will continue to be a concern with PW values rising to near 2 inches again by Monday evening. The pattern through the rest of the week will feature the upper trough sitting nearly stationary over the southern Appalachians, stuck between a large ridge over the desert SW and a ridge over the western Atlantic. This will result in a chance of showers each day, mainly with a diurnal trend and favoring the higher terrain. With a good amount of cloud cover expected and the New England surface ridge continuing to extend southward, temperatures will be a little below normal with highs in the lower to mid 80s for most of the week. && .AVIATION... (06Z TAFS) Issued at 133 AM EDT Sun Aug 3 2025 Low clouds will likely remain persistently MVFR at TYS and CHA as rain showers re-develop across the western half of the area during the day tomorrow. Improvement in CIGs is most likely around or after 00z. Meanwhile TRI should remain VFR and gradually exit the light rain that has plagued the region. Thunder chances are very low through the period, with only a 10-20% chance of occurrence between 12z and 00z. Light winds. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 76 66 79 66 / 70 20 30 40 Knoxville McGhee Tyson Airport, TN 78 65 82 66 / 60 30 30 40 Oak Ridge, TN 78 65 81 66 / 60 30 30 30 Tri Cities Airport, TN 78 59 82 62 / 20 20 20 30 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...DGS AVIATION...Wellington