Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
FXUS64 KMRX 311918
Area Forecast Discussion
National Weather Service Morristown TN
318 PM EDT TUE MAY 31 2016
.SHORT TERM...(Today and tonight)...Less convective activity today
so far this afternoon and most showers and thunderstorms have been
short lived with a few over the northern plateau...southwest
Virginia...southern valley and northeast Tennessee mountains. Put
in a few showers and storms through 00Z plateau and southwest
Virginia but expect showers to end sooner than monday evening.
Upper level ridge holds tonight and wednesday with only a slight
increase in moisture wednesday. Expect about a 20 to 30 percent
coverage of showers and storms with more over the plateau and
higher elevations. The warm temperatures will continue with highs
again in the mid 80s to lower 90s near Chattanooga.
.LONG TERM...(Wednesday night through Tuesday)...A low pressure will
move through the Ohio Valley with an associated frontal boundary
moving in to the area Wednesday night in to Thursday morning. Models
differ slightly on timing...but the front looks to stall Thursday
morning through Friday afternoon. Low level flow is weak but from
the southwest through most of the extended. With the weak SW flow
Thursday afternoon and Friday afternoon...expect PW values to be
above normal for this time of year. Expecting mostly
diurnal type thunderstorms both days. Instability values of 2500
-3500 J/kg will allow for strong updrafts...though the winds are
weak throughout the mid and upper levels. Not expecting fast
movement with these storms...with downdraft strong winds and locally
heavy rainfall totals.
Friday night through Monday...low pressure develops over the
northern plains...with an associated trough swinging down through
the TN valley by Sunday afternoon. Confidence is low coverage of
showers and thunderstorms...so kept chance precip in Saturday late
morning through Monday morning. Expecting widespread to scattered
showers with isolated thunderstorms each afternoon. The best chance
for coverage looks to be Sunday afternoon...along with the best lift.
Higher pressure and northwest flow fills in Monday afternoon through
Tuesday...with clearing skies and drier weather.
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 66 90 68 88 / 10 20 20 50
Knoxville McGhee Tyson Airport, TN 65 87 67 86 / 10 20 20 50
Oak Ridge, TN 64 88 67 86 / 10 20 20 50
Tri Cities Airport, TN 60 85 64 84 / 10 20 30 60