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

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060
FXUS64 KMRX 060231
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
1031 PM EDT Sun May 5 2024

...New UPDATE...

.UPDATE...
Issued at 1022 PM EDT Sun May 5 2024

Forecast is on track tonight so minimal adjustments were made. A
narrow line of broken showers and thunderstorms has been making
its way into East Tennessee the past half hour or so. HRRR brings
this across primarily west of Interstate 75 through the night,
bringing light rainfall to the area. Tomorrow, another bout of
scattered showers and thunderstorms still looks to be on track,
some locations may see several showers or storms. A couple of
very isolated areas (Jellico and the Rockwood Airport) received
near an inch of rain in a short order today, those who have
received decent rains the last couple of days will be more at risk
of nuisance flooding or worse as the next several days of
thunderstorms commences.


&&

.SHORT TERM...
(This evening through Monday)
Issued at 245 PM EDT Sun May 5 2024

Key Messages:

1. Scattered showers/storms this afternoon will diminish this
evening.

2. Increasing chances of showers and thunderstorms later tonight
into Monday.

Discussion:

Weak upper level ridging over us to start will exit east this
evening, and an upper level shortwave and associated longwave
troughing will move over the region later tonight into Monday. An
area of modest upper divergence associated with a right entrance
region of the jet will move across our area later tonight into the
first half of Monday as well.

After the more diurnally driven late afternoon convection diminishes
this evening, we will see an area of showers with some embedded
thunder moving from southwest to northeast across our area later
tonight into Monday.  There will likely be a bit of lull behind this
main band, but as the atmosphere recharges with some heating
(afternoon MLCAPES will likely approach 1000 J/kg at least in the
across the south/central) and the axis of the upper trough continues
to move east over our area, we will see additional showers and
thunderstorms around during the afternoon hours.

&&

.LONG TERM...
(Monday night through next Sunday)
Issued at 245 PM EDT Sun May 5 2024

Key Messages:

1. Showers and thunderstorms are likely most days through much of
the week.

2. Most organized and possibly strongest storms could come Tuesday
into Thursday.

3. With several days of rainfall flooding threat will increase next
week.

Discussion:

Monday night will see another day of showers and thunderstorms as
the slow moving shortwave slides through the area helping to spark
off storms. We will continue the trend of moderate to low CAPE and
weak shear leading to similar storm structures as we`ve seen in the
past few days. Tuesday will see a chance for a bit more organization
when it comes to storms as a strengthening jet moves towards the
Ohio Valley, and a LLJ begins to nose into the region. Several
rounds of storms are possible with strong winds and flooding looking
to be the primary concerns with storms at this time.

By Wednesday, the jet will remain across the same area with a
southern jet strengthening to in excess of 100 knots. A frontal
boundary should be located across the Plains and making it`s way
eastward. This should provide a larger divergent pattern aloft and
850mb flow possibly reaching 40 kts by the evening and into Thursday
while the frontal boundary approaches from the northwest. Convection
during this timeframe would likely be even more organized than on
Tuesday. As with the convection on Monday/Tuesday strong winds and
heavy downpours leading to flooding still looks to be the primary
concern through the middle of the week.

By Thursday the front will move into the area allowing for a focus
for yet even more focused shower and thunderstorm activity. And
forecast confidence continues to be low several days out and with
lots of atmospheric changeover between now and Thursday.

Almost all models point to a drier and cooler weekend once the front
passes through with temperatures barely eking into the 70s for many
locations Friday through the end of the weekend. And while there are
some low end precipitation chances still possible, expect most
locations will finally get a chance to dry out over the weekend.

&&

.AVIATION...
(00Z TAFS)
Issued at 737 PM EDT Sun May 5 2024

Scattered SHRA and TSRA possible at times through the next 24
hours. Winds will be light outside of any storms at the terminals.
A line of convection moving across Alabama will likely reach CHA
by 02-03z, bringing gusty winds and temporary VIS restrictions.
Tomorrow morning a brief period of MVFR CIGs is expected before a
return to VFR. Tried to time out most likely times of convection.
Additional TSRA will likely be in the region by the afternoon to
the end of the period, even if not at the terminals.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             66  83  66  86 /  60  60  30  50
Knoxville McGhee Tyson Airport, TN  63  79  63  83 /  40  70  50  60
Oak Ridge, TN                       63  79  63  82 /  40  70  50  60
Tri Cities Airport, TN              60  78  60  81 /  30  70  40  70

&&

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

$$

SHORT TERM...Wellington
AVIATION...Wellington