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

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681 FXUS64 KMRX 121119 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 719 AM EDT Wed Jun 12 2024 ...New AVIATION... .SHORT TERM... (Today and tonight) Issued at 250 AM EDT Wed Jun 12 2024 Key Messages: 1. A warming trend is expected through the week. Discussion: Currently, satellite and area observations show a good deal of high level clouds moving across much of the area. Also, an area of 5-6kft broken clouds over northeast Tennessee. Expect a good deal of high clouds to remain with scattered/few lower clouds cover producing an overall partly sunny day. Dry air mass will allow temperatures to warm nicely today close to near normal. For tonight, plenty of high clouds remain. Overall, persistence weather pattern with surface ridging and weak west/northwest flow aloft. && .LONG TERM... (Thursday through Tuesday) Issued at 250 AM EDT Wed Jun 12 2024 Key Messages: 1. Above normal temperatures and rising humidity through the weekend. 2. Increasing rain chances possible Monday-Tuesday but model differences lead to low confidence. Discussion: At the start of this period, surface high pressure centered off the Mid-Atlantic coast will extend SW across much of the Southeast, while in the mid/upper levels, a large ridge will be over the southern Plains and southern Rockies. A broad trough will be crossing the Great Lakes, pushing a cold front into the OH Valley. A few isolated showers or storms are possible in the mountains Thursday afternoon with daytime differential heating and little capping. On Friday the cold front will move into KY with a slight southward dip of the midlevel trough. Convection with the front will be weakening as it nears our area, and will have just a slight chance PoP in the afternoon for SW VA. The front will stall near our northern counties, with the main impact being lower dewpoints on Saturday. The large ridge over the Plains will be shifting eastward on Saturday, which should suppress convective potential and bring high temps in the 90s for the TN Valley. Sunday will have the highest heat indicies, with the ridge aloft over the region and a southerly low level flow increasing moisture. Southern and central Valley areas may exceed 100 heat index in the afternoon. The potential for showers and thunderstorms increases on Monday and Tuesday as the ridge axis shifts east of the Appalachians. The exact position of the ridge will determine our rain chances, and the models are not in good agreement with this. The GFS has a large plume of Gulf moisture across MS/AL and Middle/West TN, while the ECMWF keeps this moisture along and west of the MS River. For now, will cut back the NBM PoPs a little, and have chance PoPs in the western half and slight chances east both days. && .AVIATION...
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(12Z TAFS) Issued at 700 AM EDT Wed Jun 12 2024 VFR conditions will continue at all TAF sites through the forecast period. Dry west to northwest flow aloft and surface ridging can be expected. The surface ridging will produce light winds generally out of the north less than 10 knots.
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&& .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 88 67 92 69 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 85 64 89 67 / 0 0 10 0 Oak Ridge, TN 85 63 89 66 / 0 0 0 0 Tri Cities Airport, TN 84 60 87 63 / 0 0 10 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM...DH LONG TERM....DGS AVIATION...DH