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000
FXUS64 KMRX 060706
AFDMRX

AREA FORECAST DISCUSSION
National Weather Service Morristown TN
306 AM EDT Thu May 6 2021

.SHORT TERM (Today and Tonight)...

Key Message:

1) Below normal temperatures expected today and for the next several
day.

2) Precipitation chances return this evening.

Discussion:

Generally quiet weather is expected today as the front is well off
to our east, and winds are beginning to slowly shift to a more
northerly component. This shift has also allowed skies to clear out
and as a result we could see fog form in the low lying areas this
morning. This dry air will stay in place over us today forcing the
skies to remain fairly clear. Cloud coverage will begin to increase
later in the day and overnight as a broad trough begins to move
through the eastern half of the United States. CAMs are in fairly
good agreement that a line of showers and thunderstorms will develop
across the Ohio River Valley in western KY and move eastward during
the afternoon and evening hours today. Expect coverage and intensity
of storms to decrease as they move closer to the forecast area
tonight. Will keep lower end precipitation chances in the forecast,
with the better chances for rain coming after sunset. Highest
precipitation chances will be in northeast TN and southwest VA
closer to the better forcing in the mid/upper levels of the
atmosphere.

ABM

.LONG TERM (Friday through Wednesday)...

A broad trough will be over the eastern Conus at the start of the
period, putting our area in a NW flow that will produce below normal
temperatures on Friday and Saturday. Underneath the trough on
Friday, scattered showers are expected over northern sections where
low level lapse rates will be steep. Cold advection behind the
exiting trough will result in high temps only in the 60s on Friday
and Saturday, with 50s in parts of SW VA and the mountains. Lows
Friday night will be mainly in the lower to mid 40s, with upper 30s
in some northern spots and the mountains.

Light precip will be possible on Saturday due to increasing
isentropic lift as the low to midlevel flow shifts to a W-SW
direction. A weak shortwave trough and its surface low track across
the OH Valley on Sunday, bringing higher chance PoPs to the area
during the day, then rising to likely Sunday night and Monday
morning as the trailing cold front enters the area. Given the lack
of amplification in the mid/upper flow, severe weather is unlikely
and will only mention a chance of thunderstorms.

A zonal flow aloft continues through Wednesday, which results in a
stalled surface boundary somewhere near our southern border.
Details of the frontal position and weak disturbances aloft this
far out are unclear, so confidence is low. Some slight chance PoPs
will be mentioned for southern sections on Tuesday, spreading
north and increasing to chance PoPs on Wednesday as the models
show some general agreement on the development of a low pressure
system over the Plains by mid-week. Since we are expected to be on
the northern side of the boundary, temperatures will continue
below normal for the first half of next week.

DGS

&&

.AVIATION...
06Z TAF DISCUSSION.

Biggest weather concern for the next 24 hours will be the
possibility of fog early in the morning. Lowest dew point
depression is in northeast TN and southwest VA, but this is also
where clouds are continuing to linger. Clouds could hold off the
fog tonight, but still think there`s a decent chance to see
reduced visibilities in the river valleys. Expect VFR conditions
afterwards for the rest of the day.

ABM


&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             72  48  68  48  69 /  10  20   0   0  30
Knoxville McGhee Tyson Airport, TN  68  47  64  47  64 /  10  30  10   0  30
Oak Ridge, TN                       69  46  64  45  64 /  10  30  10  10  30
Tri Cities Airport, TN              65  44  59  42  61 /  10  30  50  10  20

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&

$$