979
FXUS64 KMRX 031926
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
326 PM EDT Thu Apr 3 2025

...New SHORT TERM, LONG TERM...

.SHORT TERM...
(This evening through Friday)
Issued at 253 PM EDT Thu Apr 3 2025

Key Messages:

1. Isolated severe storms are possible across the northern Plateau
and southwest Virginia through this evening. Main concern being
damaging winds and hail. A tornado is possible.

2. Summer-like temperatures will continue through Friday. Highs
will be near 20 degrees above normal. Near Record to record highs
are possible.

Discussion:

Currently, a quasi-stationary boundary remains across southeast
Kentucky to middle Tennessee. This boundary will be a focus for
near severe storm development this afternoon and evening. SPC
meso-analysis shows 0-3km CAPE of 100-125, MLCAPE of 1000-1500,
and mid-level lapse rates of 6.5 degrees producing Hail CAPEs of
500. Plenty of effective shear near 55 knots and 0-1km shear of 20
knots. Given these parameters, we expect another round of
supercell development along and near this boundary. Main concern
will be damaging winds and hail but can not rule out a tornado.

By late this evening, the convective activity will diminish with
partly/mostly cloudy sky. Mild overnight temperatures are
expected.

For Friday, upper ridging and warm mid-level temperatures will
inhibit convection development. Can not rule out an isolated
storm. Main weather story will be the unseasonably very warm
conditions. Near record to record high temperatures are expected.

Date    Chattanooga    Knoxville      Tri-Cities     Oak Ridge

04-04   88(1934)       87(1934)       83(2023)       84(1999)

&&

.LONG TERM...
(Friday night through next Thursday)
Issued at 253 PM EDT Thu Apr 3 2025

Key Messages:

1. Abnormally warm weather pattern continues Saturday, with high
temperatures around 20 degrees above normal and near record highs.

2. Showers and thunderstorms affect the area Sunday, mainly in the
morning, with potential for strong storms with heavy rainfall.

3. Much colder temperatures Monday through Wednesday, with lows near
to below freezing Tuesday and Wednesday mornings.

Discussion:

Friday night we continue with strong ridging aloft centered over the
SE coast, as well as surface high pressure directly underneath. The
pattern will still be blocked as deep troughing dominates the west
and ridging over the east. The front stalled to the west is expected
to generally remain in place until it is pushed east later Saturday
into Sunday. We will remain under the "high and dry/warm" sector
until the pattern gets moving again, sending the system our way this
weekend. With really high heights and southerly flow, high
temperatures will max out around 20 degrees above normal with
readings in the upper 80s across the valley Saturday. 90 degrees may
be possible somewhere. Our climate sites will ultimately be flirting
with either breaking the record high or tying them.

Daily Record High Maximum Temperatures for Saturday

Date    Chattanooga    Knoxville      Tri-Cities     Oak Ridge

04-05   89(2023)       89(2023)       86(2023)       88(2023)

By Saturday, troughing will start shifting our direction,
suppressing the SE ridge. By late Saturday and into the early hours
of Sunday, the mass precipitation axis that is expected to park over
the MS Valley to OH Valley region, will finally reach us, bringing
the possibility of severe storms, and especially heavy rainfall.
Latest totals from late Saturday to early Monday, place the heaviest
rainfall of possibly over 2 inches south of I-40, with amounts
lessening further north and north east. SPC Day 3 issued this
morning, has our western CWA under a tight gradient with MRGL to
SLGT, and the 15% area south of us for Day 4, but will need to watch
for the potential of severe weather. Timing will play a role with
the line possibly moving through during the very early morning hours
Sunday up until before peak heating. Instability may be limited
during that window.

Following the front`s passing, the latter half of the long term will
be night and day compared to the first half. Drastic height falls
under the trough, NW flow, and 850 temperatures dipping below 0C,
will provide a couple days of below normal conditions, especially
the low temperatures anticipated Tuesday and Wednesday morning.
Wednesday may be the coldest with many values around or below
freezing. Heads up to those who may have planted sensitive plants
early. Cold high pressure will be diving down from Canada with much
lower heights aloft. A shortwave and rather weak looking system, may
impact the area Wednesday into Thursday, but models are in great
disagreement at this time.

&&

.AVIATION...
(18Z TAFS)
Issued at 200 PM EDT Thu Apr 3 2025

Windy conditions through this evening will be the main concern
for the TAFs. Gusts up to 30 knots are possible especially at TYS.
Otherwise, mainly VFR conditions but with ceilings of occasional broken
4-5kft at TYS and CHA. Low confidence of a shower or thunderstorm
at TRI for this afternoon.

For Friday morning, continued mainly VFR conditions at all TAF
sites with southerly winds gusting to 15 knots by Noon.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             69  88  65  88 /  10  10   0   0
Knoxville McGhee Tyson Airport, TN  68  87  66  88 /   0  10   0  10
Oak Ridge, TN                       67  86  65  87 /  10  10   0  10
Tri Cities Airport, TN              63  85  62  86 /  20  20   0   0

&&

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

$$

SHORT TERM...DH
AVIATION...DH