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

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399 FXUS64 KMRX 010825 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 325 AM EST Thu Dec 1 2016 .SHORT TERM...
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(Today and Tonight)... Surface high pressure will build across the forecast area today. Dry zonal flow aloft will aid in providing clear skies for the short term period across much of the region. Clouds will linger a bit longer across the north as an upper low slowly lifts out of the Great Lakes region, but should exit the area by evening. Seasonable temperatures are expected, with highs in the upper 40s to mid 50s and lows tonight near freezing. .LONG TERM...(Friday through Thursday)... Friday and Saturday look to be very pleasant days under the influence of a middle level ridge with plenty of sunshine and daytime highs about normal for this time of year. The next round of sensible weather begins Saturday night. Guidance now seems to be coming together on this system whereby GFS, ECMWF, and GFS Ensemble all indicating a middle level low over northern Mexico separates from the polar jet by Saturday and begins pumping moisture NE into the SE US. Meanwhile, rather strong polar shortwave swings east across the Ohio Valley on Sunday. With some colder air entrenched across the Ohio Valley late Saturday, this event begins as an overrunning situation where portions of NE TN and SW VA, reaching temps below 32 overnight could see a brief period of mixed pcpn Sunday morning before becoming all rain shortly after sunrise. By late Sunday the middle level low originating in Mexico begins to push NE while continuing to pump moisture across the area through Tuesday creating an extended period of unsettled weather...and welcome rains...across the area. By late Monday surface low develops ahead of the middle level feature and tracks NE across West TN into the Ohio Valley. ECMWF and GFS are beginning to come together on this solution which is good news for the area as this looks to be another decent rainmaker. Model fcst PW values Monday night climb above 1 inch in both ECMWF and GFS...hopefully taking another bite out of our drought situation. As this system exits... there is a brief intermission through Wednesday before a digging polar trough moves eastward out of the Rockies and into the Mississippi Valley by Wednesday night with another round of pcpn possible on Thursday.
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&& .PRELIMINARY POINT TEMPS/POPS...
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Chattanooga Airport, TN 55 34 57 35 / 0 0 10 10 Knoxville McGhee Tyson Airport, TN 53 32 52 32 / 0 0 10 10 Oak Ridge, TN 54 32 53 32 / 0 0 10 0 Tri Cities Airport, TN 48 30 49 28 / 10 0 10 10
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&& .MRX WATCHES/WARNINGS/ADVISORIES... NC...None. TN...None. VA...None. && $$ EMH/EJH

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