Area Forecast Discussion
Issued by NWS Huntsville, AL

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871
FXUS64 KHUN 050648
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
1248 AM CST Wed Feb 5 2025

...New AVIATION...

.NEAR TERM...
(Tonight)
Issued at 904 PM CST Tue Feb 4 2025

A dense mid level stratus deck will continue to expand east across
the area tonight with overcast conditions expected area wide by
the morning. This cloud cover will help keep temperatures well
above normal tonight, with lows only dropping into the low to mid
50s. Reduced visibilities could become an issue overnight given
the amount of low level moisture, but a Dense Fog Advisory is not
planned at this time. Low rain chances (20-30%) will move from
west to east during the early morning hours, but most locations
should remain dry tonight. Only minor changes were made to cloud
cover during the evening update, but otherwise the previous
forecast remains on track.

&&

.SHORT TERM...
(Wednesday through Thursday night)
Issued at 157 PM CST Tue Feb 4 2025

An amplifying shortwave will shift from the southern Plains into
the Mid-Mississippi/lower Ohio Valley Wednesday into Wednesday
night, forcing the aforementioned boundary to creep back northward
into the Tennessee Valley as a warm front. Additionally, deep
layer forcing from the deepening shortwave and the northward
advancing front should lead to more widespread development of
convection from the mid/late morning hours through the afternoon
and early evening. An initial glance at model soundings indicates
some meager CAPE values aloft which will allow for some elevated
convection through the early afternoon.

With limited surface heating and relatively poor lapse rates, it
is uncertain exactly what the thermodynamic profile will be by the
afternoon hours on Wednesday across the region. However, deep
southerly flow aloft will aid in moisture transport and the
advection of a warmer air mass -- with highs in the upper 60s to
lower 70s being common once again. Probabilistic guidance is
hinting at medium to high chances of at least a couple hundred
J/kg of SBCAPE -- mainly along/west of I-65 by the mid/late
afternoon and early evening.

With convection continuing to develop with the advancing warm
front, and a 35-40 kt LLJ pushing northward enhancing the bulk
shear values, think some organized clusters of storms may be in
the cards during this late day/peak heating timeframe. If this
surface-based instability is realized, a few storms may be locally
strong to perhaps marginally severe with gusty/damaging winds
being the main concern. By the early evening, precipitation should
be tapering off as the front lifts northward toward the TN/KY
border area and despite the boundary layer remaining surface-
based, convection (and the primary severe threat) will remain
displaced further to the north along/north of I-40.

Deep southerly flow will reinforce this warm/moist air mass on
Thursday, and with a few breaks in the clouds temperatures will
be able to climb into the low to mid 70s by the afternoon. The
aforementioned boundary to the north will then drop back to south
as a weak cold front late Thursday afternoon/evening into Thursday
night, bringing high chances (70-90%) for showers/storms. With
very limited instability Thursday night, feel like most of the
convection will be elevated in nature and threat for anything
strong will be low.

&&

.LONG TERM...
(Friday through Monday)
Issued at 432 AM CST Tue Feb 4 2025

The extended portion of the forecast period will begin on Friday,
with a stalled front likely to bisect the local area in an E-to-W
fashion. Latest extended range model data suggests that the
boundary will retreat northward on Friday afternoon/evening, as
the eastward motion of a broader longwave upper trough (across the
northwestern CONUS) initiates development of another lee cyclone
across eastern CO. Present indications are that the forecast area
will be entrenched within the warm sector of this cyclone on
Saturday, with low clouds and some light showers possible at
times. However, higher probabilities for additional showers (and
perhaps a few thunderstorms) will come from late Saturday night-
early Sunday morning as the surface low ejects northeastward into
IN/OH, sending a stronger cold front southeastward into the TN
Valley. Given the orientation/location of the broader longwave
trough on Sunday, lift above the shallow postfrontal inversion
will support widespread/cold anafrontal rainfall late Sunday
morning, which should gradually dissipate from NW-to-SE Sunday
afternoon as the depth of the cool/dry airmass increases. Lows on
Monday morning will fall back into the mid 30s, with a moderately
strong north wind providing wind chills in the u20s-l30s. Chances
for rain may begin to increase once again by Monday afternoon as
yet another area of low pressure forms over the southern High
Plains, but this is highly uncertain at this time range.

&&

.AVIATION...
(06Z TAFS)
Issued at 1248 AM CST Wed Feb 5 2025

VFR conditions exist at the HSV/MSL terminals at the present
time, featuring calm winds and broken layers of stratus btwn 3.5-6
kft AGL. As a warm front begins to lift northward thru the region
later this morning, lgt SHRA will become more prevalent and both
cigs and vsby should fall into the MVFR range. Occasional periods
of IFR conditions will be possible during the day as clusters of
warm sector SHRA/TSRA spread northeastward across the region, and
AWWs may be required for lightning. Afternoon precipitation will
spread northeastward and out of the region this evening, with SSW
flow expected to gradually strengthen thru 6Z Thursday.

&&

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

&&

$$

NEAR TERM...25
SHORT TERM...AMP
LONG TERM...AMP
AVIATION...70/DD