Florence, Alabama 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

460
FXUS64 KHUN 152203
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
503 PM CDT Thu May 15 2025

...New AVIATION...

.NEAR TERM...
(Remainder of this afternoon and tonight)
Issued at 301 PM CDT Thu May 15 2025

There have been no significant changes to previous near term
forecast reasoning since the update earlier this morning. However,
timing of potential impacts from a developing MCS (currently in
progress across central AR), as well as another MCS (modeled by
12Z CAMs and the last few runs of the HRRR to develop later this
evening across southwestern AR) will need to be refined as both
systems evolve and a path/speed become more apparent. Should
storms impact our CWFA, the highest probabilities of occurrence
remain for locations along and north of the AL-TN border. Although
conditional on the path of the MCS clusters, both deep-layer and
low-level shear (as well as instability) will support a risk for
strong winds and hail.

Previous Discussion:
A deepening surface low will lift northward across eastern
portions of the Dakotas today and begin to occlude across western
MN tonight, in association with a negatively-tilted 500-mb
shortwave trough (initially across SD/NE) that will evolve into a
closed low upon reaching northern MN by 12Z Friday. Although the
downstream ridge (translating eastward across the TN Valley) will
maintain a strong capping inversion across our region, light-
moderate SSW flow at the surface beneath a 25-35 knot WSW low-
level jet will provide sufficient low-level ascent to generate
pockets of light rain beneath the inversion, warranting a 15-20%
POP through at least early this afternoon. Due to competing
influences from low-level warm advection and an abundant coverage
of mid/high-level stratiform clouds, we will stick with NBM
suggested highs in the mid 80s.

To the north/west of our region, a dryline extending southward
from the previously mentioned surface low will assume a more
slanted orientation throughout the near term period as the
northern portion surges eastward across southern IA/northern
MO/northwest IL and into the Lower Great Lakes, while the southern
portion remains nearly stationary from southern OK into central
TX before retreating westward overnight. The intermediate portion
of the dryline (extending from central IL into northeastern OK)
will serve as a focus for convective development later this
afternoon as it drifts southeastward and intercepts an
increasingly moist airmass featuring dewpoints in the u60s-l70s.
Present indications are that this activity will persist across the
same general region this evening, with upscale growth into
multiple small clusters possible during the early morning hours
Friday as the strengthening low-level jet becomes aligned nearly
parallel to the surface boundary. This activity should spread
east-northeastward into the Cumberland Plateau region of eastern
KY/middle TN with time and largely miss our CWFA to the north, but
may clip our southern TN counties (particularly from 9-12Z)
warranting a low (15-20%) POP. Due to the presence of a
moist/unstable boundary layer and WSW low-level jet of 25-35 knots
(beneath WSW mid-level flow that will be increasing into the
55-65 knot range), a conditional risk for a few stronger
thunderstorms will exist across southern TN. The main hazards with
this activity would be wind gusts up to 40-50 MPH and small hail.

&&

.SHORT TERM...
(Friday through Saturday night)
Issued at 1131 AM CDT Thu May 15 2025

Current short range model solutions suggest that multiple small
convective clusters (north of our CWFA) will continue to spread
generally east-northeastward and into the central/southern
Appalachians after 12Z Friday, but may continue to impact our
southern TN counties through 15Z, warranting a low (15-20%) POP.
Although this convective regime will largely dissipate by late
Friday morning, a remnant mesoscale differential heating or
outflow boundary may serve as a focus for redevelopment of
thunderstorms across southwestern MO/northwestern AR by mid-day.
Present indications are that the intermediate portion of the
moisture gradient boundary/remnant dryline (extending from the
western Ozark Plateau into southern IN) will lift northward
throughout the day as a distinct mid-level vort max (peripheral to
the larger closed cyclone aloft) tracks eastward from eastern CO
into northern MO, with development of supercells expected across a
broad portion of the open warm sector tomorrow afternoon from
southeastern MO/northeastern AR eastward into the central OH
Valley/northwestern TN.

The supercell regime will continue to spread eastward into the
Cumberland Plateau region early tomorrow evening, but may also
clip a portion of northwest AL/southern TN, with an increasing
risk for severe wind/hail and tornadoes in this region perhaps as
early as the 2-4Z timeframe Saturday. However, it still appears as
if our primary severe weather event will occur with an MCS that
will initiate from extensive convection over the Lower OH Valley
early Friday evening and spread southeastward with time, reaching
the northwest portion of the CWFA between 4-6Z. Upon initial
arrival in our region, the MCS will feature a risk for severe
wind/hail and perhaps a couple of brief tornadoes, as WSW flow
aloft of 55-65 knots will be favorably aligned with a 40-50 knot
WSW low-level jet for an extended period from late Friday
afternoon-early Saturday morning. However, with time, the MCS will
gradually lose intensity as it spreads southeastward, exiting the
forecast area by 10-12Z.

Lingering light rain may continue for a couple of hours after 12Z
Saturday (especially south of the TN River), but extensive
convective outflow in the wake of the MCS will surge southward,
focusing any redevelopment of afternoon thunderstorms on Saturday
from northern MS southeastward into central AL/GA. As a shortwave
disturbance lifts northeastward across the southern Rockies on
Saturday, surface pressures will begin to fall across eastern
NM/TX Panhandle, with the remnant outflow boundary predicted to
retreat northeastward on Saturday night. This may result in
increasing probabilities for elevated convection across our region
in the 3-9Z timeframe Sunday in the presence of weak elevated
CAPE.

&&

.LONG TERM...
(Sunday through Wednesday)
Issued at 931 PM CDT Wed May 14 2025

A rather flat 5h pattern over the southeast U.S. will become more
amplified from Sunday into Tuesday. An upper ridge will amplify
and shift east into the Great Lakes south to the Gulf Coast. A
longwave will follow into the Plains states and deamplify upon
reaching the MS River Valley Tuesday and Tuesday Night. The
residual surface outflow from convection on early Saturday will
lift northward Saturday night into Sunday, keeping low to medium
chances of MCS or at least scattered convective development in
play. As the Plains surface cyclone emerges into KS/NE on Monday
into Monday night, the boundary will lift northward with
thunderstorm chances decreasing. The low will reach the upper MS
valley on Tuesday night, with a trailing cold front into AR/LA.
Low chances of thunderstorms will spread east into the region
Tuesday into Tuesday night as a result. Warm advection will
increase substantially through early next week at the surface thru
8h as a south-southwesterly low level jet increases across the
entire Gulf state region northward ahead of the trough/cold front.
8h temperatures should warm back into the mid to upper 10s.
Surface high temperatures will be in the lower 80s Sun, lower to
middle 80s Mon, and middle to upper 80s Tue and Wed. Lows will be
mainly in the 60s during this period, but could be as warm as 70
Tuesday morning.

&&

.AVIATION...
(00Z TAFS)
Issued at 503 PM CDT Thu May 15 2025

VFR flight weather conditions are forecast at both KMSL and KHSV.
However, there is a low chance of TSRA clipping far northwest AL
and southern middle TN between 03-10Z. Another complex of TSRA may
also affect areas north of AL and southern middle TN after
12-14Z.

&&

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

$$

NEAR TERM...70
SHORT TERM....70
LONG TERM....17
AVIATION...17