Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN

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334 FXUS64 KMRX 240805 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 405 AM EDT Mon Oct 24 2016 .SHORT TERM (Today and Tonight)... Surface high pressure continues to dominate the short term forecast with clear skies, unseasonably warm daytime highs, seasonably cool overnight lows and low relative humidities. Passage of a backdoor cold front by this evening will bring northerly surface winds and reinforce the dry low-levels. Aloft, ridge of high pressure continues to contribute to the dry deep layer northwesterly flow with PWs across the area stuck in the 0.3-0.6 inch range. Model soundings consistently show a very dry layer at around 800-850 MB with dew point depressions on the order of 20-35 area wide. Bottom line...this dry air mass will allow afternoon RH values to dip into the low 30`s across much of the East Tennessee Valley. The result is a continued marginal fire weather risk across the area during this prolonged period of drought. .LONG TERM (Tuesday through Sunday)... No change in mild mostly clear pattern Tuesday and Wednesday with Upper level ridge centered over the south central states. Northwest flow aloft and dry air mass to continue. Highs in the 70s lower elevations and 60s higher elevations. A cool night again Tuesday night with lows upper 30s NE to lower 50s SW. Surface low develops over Iowa Wednesday then moves into the Ohio Valley Wednesday night. South to Southwest flow will increase Wednesday night as clouds increase ahead of this system. Showers move in late Wednesday night and Thursday morning across east Tennessee as cold front approaches. Models still keep most of the energy with this system over the Ohio Valley and Great Lakes so only brief period of showers across east Tennessee. Some instability present but thunder threat Thursday still looks low. Rain will move out Thursday night with skies clearing and high pressure building back in Friday. A new low pressure area moving southeast across Great Lakes late Friday and Friday night...then the Ohio Valley on Saturday should get close enough to spread clouds and a chance of rain to northern sections of the area Saturday and northeast sections Saturday night. Temperatures to remain above normal through the extended. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 80 49 77 49 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 76 44 73 45 / 0 0 0 0 Oak Ridge, TN 76 45 74 45 / 0 0 0 0 Tri Cities Airport, TN 72 38 69 38 / 0 0 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...None. TN...None. VA...None. && $$ EJH/TD is the U.S. government's official web portal to all federal, state and local government web resources and services.