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

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797 FXUS64 KMRX 270724 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 324 AM EDT SAT AUG 27 2016 .SHORT TERM (Today and Tonight)... Current water vapor imagery and RAP upper air analysis indicate a 594 dm high located just to northeast of the area. A weak shortwave trough in the upper level flow moving around the periphery off the ridge has lead to a few showers and storms continuing at this early hour across Western Kentucky. There were a few showers lingering across southern portions of the forecast area late tonight but those showers have now come to an end. At the surface, an E-W oriented boundary stretches across the Central Plains extending eastward into the Mid-Atlantic. Closer to home, low level winds are weak with dewpoints currently in the upper 60s to mid 70s. With these conditions, expect a few areas of patchy fog this morning but not expecting anything as bas as yesterday morning. For today, models indicate that a weak 300mb jet streak will move across the region around the periphery of the upper level ridge. Wind speeds in this jet streak are only forecast to be around 35- 45kts but it will provide some weak lift. At the low and mid-levels, winds will be from the SE around the high located to the NE. These downsloping winds will hinder any vertical motion. PW values will range from 1.3-1.8 inches with the lower values across SW VA and higher values in SE TN. The higher values are near the 90th percentile for late August. Overall, expect isolated to scattered afternoon showers and storms with best chances across the higher elevations. Temperatures in the valley will top out in the mid 90s with the downsloping winds with max heat indices around 100. .LONG TERM (Sunday through Friday)... Little change in the overall weather pattern early in the period...so made little change in the overall forecast. High pressure will stay in control through much of the extended. As a result...will see continued above normal temperatures with highs across the valley generally ranging from the upper 80s to low 90s. The strong daytime heating will provide diurnal convection most afternoons with best chance over higher elevations. An occasional weak disturbance tracking through the region will aid convective development. There continues to be a lack on consistency late in the period but generally do not see a significant change in the weather pattern and will keep isolated to low chance pops in place for Thursday and Friday. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 95 73 92 72 / 30 10 30 20 Knoxville McGhee Tyson Airport, TN 95 72 90 69 / 20 10 30 20 Oak Ridge, TN 95 72 90 69 / 20 10 30 20 Tri Cities Airport, TN 93 69 89 67 / 20 10 30 20 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...None. TN...None. VA...None. && $$ MA/MJB

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