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

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000 FXUS64 KMRX 250906 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 406 AM EST Sat Feb 25 2017 .SHORT TERM /Today and Tonight/...
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A cold front is quickly moving into the eastern Tennessee early this morning, bringing with it a broken line of strong to severe storms. This activity is tied closely to a 50 kt 850 mb LLJ that has rotated across the region over the last 3-5 hours. Instability is limited, but would not be surprised to see this activity maintain itself over the next couple of hours, given the added lift by the LLJ. Damaging winds will be the main threat along with some small hail. Thereafter, winds will shift to the WNW and NW and drier/cooler air will quickly advection into the region. the high temperature may well occur in the morning, before northerly winds gradually stabilize/decrease them by later in the afternoon. Low stratus will linger through the morning and into the early to mid afternoon across much of the area, before breaking up late in the day. However, this brief bout of heating should not impact the temperature curve much. Winds will be quite breezy in the afternoon, helping to reinforce this cooler air mass. However, sustained winds in the 15 to 25 mph range will be below advisory criteria. Overnight, a clear and calmer night will make for good radiational cooler in the evening. A hard freeze is expected over much of the Valley, with lows in the mid to upper 20s. Thus, readings will be some 50 degrees cooler than the high temperatures recorded earlier on Friday. Quite the difference in air mass! .LONG TERM /Sunday through Friday/... Models start out with good agreement for the long term period, with surface high pressure in control for Sunday and zonal flow aloft. High pressure slides off the east coast Sunday night, and flow becomes more southwesterly for Monday. Moisture will work into the area by Monday afternoon and showers will develop for Monday into Tuesday. From here, we start to see some model differences, but the general forecast consensus is pretty good. The atmosphere will destabilize on Tuesday with a warm front approaching the area, which may help spark some thunderstorms during the day. The better chance for convection will be Tuesday night into Wednesday, with our area sitting in the warm sector ahead of another relatively strong cold front that will cross the area later Wednesday afternoon and overnight. Kept the remainder of the long term dry with high pressure building in and northwest flow setting up. Models do indicate a shortwave crossing north of the area Friday, and this could bring the chance for some showers to SW VA, but odds are too low to include at this point.
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&& .PRELIMINARY POINT TEMPS/POPS...
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Chattanooga Airport, TN 55 31 57 39 / 20 0 0 10 Knoxville McGhee Tyson Airport, TN 54 30 53 35 / 40 0 0 10 Oak Ridge, TN 54 28 53 35 / 30 0 0 10 Tri Cities Airport, TN 57 25 49 31 / 60 0 0 0
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&& .MRX WATCHES/WARNINGS/ADVISORIES... NC...None. TN...Wind Advisory until 7 AM EST this morning for Blount Smoky Mountains-Cocke Smoky Mountains-Sevier Smoky Mountains. VA...None. && $$ AMP/EMH

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