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

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS64 KMRX 231859 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 259 PM EDT Wed May 23 2018 .SHORT TERM...
-- Changed Discussion --
(Tonight and Thursday)... Deep ridging continues to dominate aloft across the southeast CONUS this afternoon, while a weak surface frontal axis slides southward into the TN valley and southern Appalachian region. With that, a few light showers have initiated, and will continue as the boundary slides south. Despite modest surface heating, lapse rates aren`t all that steep aloft, therefore the fcst will feature slight/chance pops this afternoon with comparable thunder chances, with little/no strong convection expected. Pops will taper off tonight with loss of heating, and as the boundary slides south of the fcst area and washes out. Skies are expected to sct out in the low/mid levels through the night with ample BL moisture present. Therefore, optimal radiational cooling amidst calm flow could lead to another night of patchy fog, with perhaps some valley locales being more dense. As for Thursday, pops will ramp up with heating as trends look more diurnal given no surface focusing mechanisms. Thus the fcst will feature slight chances north of I40, with chances favored along/south. Temperatures on Thursday will top out around 1.5 cats above normal. .LONG TERM...(Thursday night through Wednesday)... Will still have some northerly flow near the surface on Thursday into Friday. This should keep precipitation chances pretty low and skies mostly clear as we head towards the weekend. Southerly flow will return Friday afternoon and this will begin a long period of increased shower and thunderstorm chances this Memorial Day weekend. Thunderstorm chances will be present through most of the weekend, but as typical this time of year expect the afternoon and evening hours to see the widest coverage and strongest storms. As we move into Memorial Day and through most of next week a low in the Gulf of Mexico becomes a factor in the weather over the forecast area. There are still timing/location differences in the track of this low as it moves northward...And depending on the track of this storm we could see a decent amount of rainfall. GFS continues to bring the system up near the Southern Appalachian Mountains, while the ECMWF wants to force it off much further to the west, and keeps it much weaker. So forecast certainty for next week is pretty low at this time. But if the storm tracks closer to the forecast area we could see several days of moderate rainfall which could lead to localized flooding, especially near rivers and poorly draining areas. During the next 7 days temperatures will remain relatively steady with daytime highs in the 80`s across most of the area.
-- End Changed Discussion --
&& .PRELIMINARY POINT TEMPS/POPS...
-- Changed Discussion --
Chattanooga Airport, TN 67 87 69 84 / 10 30 20 40 Knoxville McGhee Tyson Airport, TN 65 87 67 83 / 10 30 10 40 Oak Ridge, TN 65 88 67 84 / 10 30 10 40 Tri Cities Airport, TN 59 82 62 82 / 10 20 10 40
-- End Changed Discussion --
&& .MRX WATCHES/WARNINGS/ADVISORIES... NC...None. TN...None. VA...None. && $$ CDG/ABM

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.