625
FXUS64 KHUN 141139
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
639 AM CDT Fri Mar 14 2025

...New AVIATION...

.NEAR TERM...
(Rest of tonight through Friday)
Issued at 406 AM CDT Fri Mar 14 2025

In the mid/upper-levels, a shortwave ridge will shift eastward
across the TN Valley early this morning in the wake of a trough
spreading off the southeastern Atlantic Coast. Current IR
satellite data indicates an abundant coverage of high-level clouds
currently moving overhead in the flow around the ridge, and this
along with an uptick in SE winds at the surface should largely
prevent the formation of fog. Nevertheless, with narrow dewpoint
depressions noted in regional surface obs (and temps expected to
remain steady in the l50s/E and u50s/W) a few patches of light
mist/fog can be expected in our normally fog-prone locations due
to wet soils from rainfall yesterday evening.

Over the course of the day, a strengthening mid-level shortwave
trough (currently tracking across AZ/NM) will deepen as it lifts
northeastward into southeastern NE/northeastern KS by 0Z Saturday.
As the related surface low shifts east-northeastward along the
NE-KS border, SSE gradient flow in the boundary layer will
increase considerably by this afternoon, resulting in warmer temps
in the m-u 70s after late morning stratus dissipates. A fast-
moving arc of thunderstorms is predicted to develop across eastern
KS/western MO early this afternoon in the vicinity of the surface
low`s dryline, with a more scattered coverage of storms expected
to initiate in the vicinity of a subtle confluence axis
(immediately east of the dryline) across south-central AR/north-
central LA. This activity will spread northeastward with time and
into southeastern AR/northwestern MS by sunset and may have
implications for our forecast area after Midnight, but aside from
a few sprinkles of rain this morning we expect a dry day across
the TN Valley.

&&

.SHORT TERM...
(Friday night through Sunday Night)
Issued at 938 PM CDT Thu Mar 13 2025

Severe storms will line up along the dry line/dry slot as far
south as the mid South Friday evening. The EML/capping inversion
will be a feature we will continue to monitor as it spreads into
the region. The big question Friday night into early Saturday is
will this put a lid on surface based supercellular development or
not. At this point, confidence remains somewhat uncertain on this
given CAMS, especially given weakening QG forcing. Will have to
see what the newer CAMS show tonight and into tomorrow, but from
earlier runs, it appears that the convection initially may be
forming above the cap. However, given the strength of the shear
and instability parameters, supercells would be the favored storm
type.

One thing is more certain, convection will become more widespread
Saturday morning into the midday hours across northern MS into
north AL and TN as the next wave starts to amplify UVVs and deeper
low level moisture underruns the capping inversion leading to
rapid development and expansion of storms. Again, all modes of
severe weather will be likely, including tornadoes. The models
indicate some potential for a break during the afternoon as the
morning activity lifts rapidly northward and the next jet max
rounds the base of the trough into the deep South. Given even
modest heating in advance of this, additional supercells will
develop in western TN through MS that will rapidly move northeast
into AL and middle TN during the evening hours. Again, parameters
are all favorable for tornadic supercells. There are some
indications the supercells may be more embedded within an intense
QLCS over TN into northwest AL, with more isolated supercells
further south in AL. In either case, the risk of severe weather is
heightened with intense shear due to the increasing low level jet
Saturday evening. The line of thunderstorms will shift east
during the late evening hours, likely exiting our eastern counties
from 06-09Z. Heavy and possibly excessive rain due to echo
training remains a concern, so we will monitor this closely.

Cooler north flow will arrive behind the system on Sunday with
highs in the 60s and chilly overnight lows in the middle to upper
30s.

&&

.LONG TERM...
(Monday through Thursday)
Issued at 938 PM CDT Thu Mar 13 2025

A dry start is forecast to start the upcoming work week. The
upper level trough responsible for the severe weather Friday and
Saturday is expected to be positioned along the East Coast. As it
continues to push east, an upper level ridging pattern takes shape
over much of the CONUS. Sfc high pressure will sit just to our
west on Monday allowing for northwesterly flow. This will keep
skies clear with afternoon temperatures rising into the mid 60s
with overnight lows in the upper 30s to lower 40s. As the
aforementioned high pressure center shifts further to the east,
this will bring back southwesterly flow resulting in a warming
trend heading into the middle of the week. Forecast highs return
to the low to mid 70s Tuesday and Wednesday.

The next chance for rain will be Thursday as another upper level
trough digs down across the Rockies. A sfc low is forecast to develop
over the Plains with a cold front draped southward into OK/TX. The
cold front sweeps through the Tennessee Valley Thursday bringing area
wide showers with a few embedded thunderstorms. Instability and
shear look meager this far out so severe storms are not
anticipated at this time.

&&

.AVIATION...
(12Z TAFS)
Issued at 639 AM CDT Fri Mar 14 2025

The combination of bkn-ovc high clouds and a modest increase in
SSE flow over the last few hours continues to keep early morning
fog confined to wind-sheltered valleys of northeast AL. However,
we still anticipate development of a lower stratus layer that will
provide temporary MVFR cigs at both HSV/MSL from 14-18Z. Present
indications are that skies will partially clear this aftn as
diurnal mixing becomes enhanced by an increase in sfc flow to
14G24 knots, with winds of this magnitude expected to continue for
the remainder of the TAF period. There is a low probability for
development of a few TSRA across our region from late this evening
thru early Saturday morning, and this has been included with a
PROB30 group from 8-12Z. Regardless of sparse coverage, any storms
that develop during this timeframe could be quite impactful, and
would warrant issuance of AWWs if their paths came sufficiently
close to an airport.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...None.
TN...None.

&&

$$

NEAR TERM...70/DD
SHORT TERM...17
LONG TERM...GH
AVIATION...70/DD