Dunlap, Tennessee Weather Forecast Discussion

976
FXUS64 KMRX 210613
AFDMRX
Area Forecast Discussion
National Weather Service Morristown TN
213 AM EDT Sun Sep 21 2025
...New DISCUSSION, AVIATION...
.KEY MESSAGES...
Updated at 149 AM EDT Sun Sep 21 2025
-  Above normal temperatures will persist through early next
    week.
-  A few PM showers and storms will be possible each afternoon
    today through Tuesday.
-  Cooler temperatures and increasing chances of showers and
    storms are expected Wednesday into late week. There is potential
    of isolated severe storms and flooding concerns but
    confidence is low at this time.
&&
.DISCUSSION...
Issued at 149 AM EDT Sun Sep 21 2025
Patchy fog in the early AM hours to around sunrise, especially for
those that observed rainfall this afternoon. However, high clouds
advecting across the region will help hinder chances of locally
dense fog.
An additional disturbance will translate through mean flow aloft
this afternoon and evening, promoting PoP chances in the 20-40%
range. Latest CAMs are in fairly good agreement on a decaying line
of showers and storms approaching the Cumberland Plateau by the mid-
afternoon... around 3-4pm ET. MLCAPE near 1500 J/kg and effective
shear near 15kts suggest a limited threat for a stronger storm,
especially considering DCAPE values will be less than this past
afternoon as a shift to southeasterly flow promotes increasing
dewpoints. Will opt for low probability wording in the HWO once
again, but the main concern with any stronger storm would be gusty
winds upwards of 40mph. Temperatures will remain around 3 to 5
degrees warmer than normal.
A similar pattern will be in place on Monday & Tuesday with about 20-
40% chance PoPs as additional shortwaves swing through the southern
Appalachians. However, NAMBufr soundings are less aggressive with
CAPE values suggesting an even lower likelihood of an isolated
stronger storm. While temperatures will remain above normal, minor
upper height falls will translate to the start of a gradual cooling
trend.
By Wednesday, an amplifying upper low will be entering central
portions of the CONUS. Bouts of energy rounding the base of the
trough will continue to amplify this synoptic feature, with a trough
axis potentially extending as far south as the Gulf Coast by end of
the week. Shower and storm chances will see an increasing trend
associated with strengthening upper-level divergence by Wednesday.
Increasing frontogenesis will further enhance shower and storm
chances Thursday. With repeated days of showers and storms and PWAT
values increasing to near 90th percentile values, flooding concerns
may need to be monitored along with lower confidence in potential
isolated severe activity. Wrap around moisture will linger precip
chances Friday into the weekend, but as we head further in time more
uncertainties are presented in how exactly the upper low evolves,
thus, confidence becomes limited. The anomalously low heights
will bring below normal temperatures during this time frame as
well.
&&
.AVIATION...
(06Z TAFS)
Issued at 149 AM EDT Sun Sep 21 2025
Patchy fog seems likely near or at KTRI by morning, especially given
the antecedent rainfall so introduced a TEMPO there. Otherwise
scattered showers and TS are increasing in likelihood for the
evening hours at KTYS and KCHA, introduced PROB30s for both. Highly
uncertain if any convection will be able to reach KTRI before
dissipation for the day. Otherwise winds will be generally light
today, outside of any convective gusts.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             89  67  87  66 /  30  30  30  10
Knoxville McGhee Tyson Airport, TN  87  65  86  64 /  30  20  40  20
Oak Ridge, TN                       87  64  85  64 /  40  30  40  20
Tri Cities Airport, TN              84  60  82  60 /  20  10  40  10
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DISCUSSION...KRS
AVIATION...Wellington

NWS MRX Office Area Forecast Discussion