665 FXUS64 KMRX 091127 AFDMRX AREA FORECAST DISCUSSION National Weather Service Morristown TN 727 AM EDT Tue Jun 9 2020 .UPDATE... FOR 12Z AVIATION. && .SHORT TERM...(Today and tonight)... The remnants of Cristobal will continue to move up the Mississippi Valley and into the western Great Lakes Region during the short term period as an upper level trough moves east across the Great Plains. Given moisture wrapping around the remnants of Cristobal, diurnal heating and falling heights will carry chance PoPs across the entire area today as expect more significant coverage of showers and, as convective energy increases with the heating, some thunderstorms. If any training occurs, localized flooding cannot be ruled out as well. With the loss of heating tonight, expect coverage of showers and thunderstorms to diminish early and any lingering precipitation to trend more toward just showers as convective energy wanes. Today will be on the hot and humid side with temperatures above seasonal normals once again. Lows tonight will also be well above normal. LW .LONG TERM...(Wednesday through Monday)... Interesting upper level patterns through the extended. Upper trough over the Mid-west will lift across the Ohio valley and Great Lakes Wednesday, then drier west to northwest flow aloft and surface ridging through the rest of the week into most of the weekend. For the weekend, a deep upper trough for mid June develops across the eastern third of the nation. The extended models show differences on how this upper low develops across the region but increasing convective chances are possible by late in the weekend into early next week. Now for the particulars... For Wednesday, increasing southwest flow across the Tennessee valley and southern Appalachians will pull Gulf moisture northward into the region. PWs increase to 1.8 to 1.9 inches over much of the area. Soundings show a fairly deep moisture profile with MLCAPES of 1000 to possible 1500 J/kg. Freezing levels/WBZ heights will be quite high (above 12kft) so very limited hail potential. Shear is weak with low-level jet of 25-30kts. Main concern will be potential of precipitation loading and some mid-level dry air advecting into downdraft producing localized damaging winds. Negative tileted upper trough will move mainly north of the area for late Wednesday and early Wednesday night with frontal passage in the evening hours. Greatest coverage and intensity of storms will be from mid-afternoon through the evening hours Wednesday. Frontal boundary moves across the area with surface ridging building into the area for Thursday. Drier, less humid and slight cooler air can be expected. For Thursday and Friday, surface ridging will dominate with dry west to northwest flow aloft. For Saturday through Monday, an evolving upper trough will develop across the eastern third of the nation. Again, confidence is low on the evolution of this system but increasing convection is anticipated by late weekend into early next week. DH && .AVIATION... 12Z TAF DISCUSSION. Tropical moisture will bring varying amounts of clouds, along with some showers and possible thunderstorms to the area. Outside of a heavier shower or thunderstorm, conditions will be mainly VFR for the period all sites. Main exception will be at CHA, where will include a few hours of MVFR cigs early this morning and again late in the period. Will try to time the best chance for thunder with VCTS and PROB30 groups. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 88 73 87 64 84 / 50 30 60 20 10 Knoxville McGhee Tyson Airport, TN 90 73 87 64 83 / 40 20 60 50 10 Oak Ridge, TN 89 73 87 63 82 / 40 20 60 50 10 Tri Cities Airport, TN 89 67 87 63 82 / 40 20 60 60 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$