267 FXUS64 KMRX 010726 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 326 AM EDT Tue Oct 1 2019 .SHORT TERM...(Today and Tonight)... The gist of it...the strong upper ridge is still with us, and as a result today will be another hot day with many locations seeing record breaking afternoon temperatures. Most will see no rain, but some isolated showers will be possible mainly in the higher terrain of southwest Virginia and the east Tennessee mountains. For a bit more detail, please read on. The much talked about upper ridge of late, is still hanging around. It is slightly further east than yesterday, centered over middle Tennessee as opposed to the TN/AR line, but will also be slightly weaker as the influence of a strong trough over the intermountain west begins to be felt. This will cause the eastern ridge to become more elongated in the southwest-northeast direction, with upper heights lowering only slightly. The effects of this will be negligible really, as temperatures will be virtually the same as yesterday, ranging from the upper 80s in the north to the mid 90s in the south. At these temperatures, many areas will approach or break calendar day records. For reference sake, the climate section listed below has the daily record highs for each of our four climate sites, for each day this week. Regarding rain chances today, it should be much like yesterday, with just some isolated to scattered convection over mainly the higher terrain of southwest Virginia and east Tennessee. Or in other words, areas areas furthest away from the center of the ridge. Did continue with the mention of 20-30 percent rain chances as far south as our western North Carolina counties. Think the SW-NE elongation of the ridge will allow those areas to be under, relatively speaking, lower upper heights and thus a better opportunity to see some isolated convection this afternoon. This is supported by most all guidance. However, it must be stated again that most areas will see no rain, especially for much of the valley and plateau areas. .LONG TERM...(Tuesday through Monday)... The massive ridge keeps the hot and dry trend going through much of the extended. The pressure system even retrogrades a bit to the west early in the period. This retrogression and the gargantuan ridge itself will absolutely suppress moisture return and lift ahead of a Great Lakes through Northeastern U.S. traversing upper wave. The surface cool frontal boundary will come through the region Thursday night into Friday basically dry. The good news is there will be a good ten to twelve degree drop in maximum temperatures to follow for Friday, but even these highs will still be about five to six degrees above normal for early October. The low level flow gradually shifts back to southerly as the center of the associated surface ridge slips back out into the Western Atlantic. Model forecasts have come into slightly better agreement toward the end of the long term period with another northern tier upper trough amplifying through the Mississippi Valley later Sunday on its way into the Ohio Valley on Monday. Each model hints at a weak shorter wavelength feature that makes progress across the Central Appalachians on Sunday that may spark a couple showers and possibly a thunderstorm across the Southern Appalachian region. Kept the chance for convection slight on Sunday due to the continuing strength of the sub-tropical high and great limitation of moisture return due to the western extent of the low level ridge into the Western Gulf of Mexico. Allowed a small chance pop on Monday with the advance of the northern tier upper trough and surface cold front. However, it will be interesting to see just how much precipitation will occur with this feature with much of the upper level energy advancing well north into Southeastern Canada with the track of the associated upper low. Still, each model hangs back some short wave energy through the Mid Mississippi Valley to produce considerable slowing of the surface boundary. This may help to focus a longer duration of convective precipitation across the Southern Appalachians Monday into Tuesday morning. Another positive aspect will be the extended period of scattered to broken clouds, which should help to cap off the intense late Summer heatwave. && .Climate... Afternoon temperatures through the end of the week will come close to, or possibly exceed, the calendar day record highs at all four climate sites. Below you will find a short table with the record highs for each site, for each day, along with the year in which they were set. ........Chattanooga....Knoxville....Tri-Cities....Oak Ridge 10-01...90 (1971)......92 (1884)....90 (1953).....90 (1953) 10-02...92 (1954)......93 (1884)....85 (1986).....89 (1986) 10-03...92 (1954)......94 (1884)....88 (2007).....87 (2005) 10-04...92 (1954)......94 (1884)....87 (1954).....89 (1954) && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 95 71 94 71 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 93 71 92 70 / 10 0 0 0 Oak Ridge, TN 93 69 92 69 / 10 0 0 0 Tri Cities Airport, TN 89 66 90 63 / 20 0 10 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...None. TN...None. VA...None. && $$ CD