081
FXUS64 KHUN 120844
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
344 AM CDT Mon May 12 2025

...New NEAR TERM...

.NEAR TERM...
(Today)
Issued at 344 AM CDT Mon May 12 2025

A broad area of showers and storms continues to push northward
across the Tennessee Valley early this morning in response to a
mid/upper low over Louisiana gradually pivoting to the north and
east into Mississippi. Modest, but appreciable MLCAPE of 250-500
J/kg and PWATs of between 1.3-1.5" (with a deep warm cloud layer)
favor efficient rain producing convection. The banded convective
features across northeast Alabama do bear some watching if they
persist several hours -- as they are moving parallel to the mean
flow. Showers and storms may train over this area over the next
few hours at least and a localized flooding threat may evolve if
QPF amounts out perform. However, hi-res guidance does eventually
indicate this activity will shift northward into Tennessee and
Kentucky after sunrise.

Our attention will turn to another round of showers/storms that
will redevelop later this afternoon and into the evening hours as
the upper-low meanders into the Tennessee Valley. Despite the
early morning rain, some breaks in the cloud cover later in the
morning should allow temperatures to climb back into at least the
mid 70s. SBCAPE values of 500-1000 J/kg, aided by some better
bulk shear values (around 40 kts) provided by the low pressure
system will allow for some organized convection during an
afternoon to evening window. Thus, a localized threat for severe
storms will exist, with damaging winds and hail the main threats.
Storm mode will likely be multicells and possibly a few mini
supercells. Mesoanalysis will be key later this morning -- and if
precipitation/cloud cover lingers longer than anticipated the
severe threat will be mitigated. Additionally, heavy downpours
and localized flooding concerns with the heaviest convection will
continue to exist.

&&

.SHORT TERM...
(Monday through Tuesday Night)
Issued at 920 PM CDT Sun May 11 2025

The previously-mentioned upper low is expected to gradually shift
northeast from the ArkLaMiss to the Tennessee Valley by Monday
night, then over the Ohio Valley by Tuesday night. This is
coincident with a surface low over the ArkLaMiss as well, slated
to move northeast over the Carolinas by midweek. This pattern will
keep daily medium to high (50-80%) chances of showers and storms
in the forecast through Tuesday, especially during the daytime
during peak heating hours.

While models suggest instability between 500-1500 J/kg each day,
bulk shear remains mainly less than 30 knots. The exception to
this is over northeast Alabama Monday afternoon, when shear values
increase to between 30-35 knots by the late afternoon into the
early evening. Thus, conditions over northeast Alabama Monday
afternoon appear conducive for the development of a few strong to
marginally severe storms, with damaging winds the main threat.
This coincides with the Storm Prediction Center`s outlook for
Monday, which highlights areas mainly east of I-65 in a Marginal
Risk (level 1 of 5) of severe weather.

Shower and storm chances are then forecast to decrease to be low
to medium (15-35%) by mid-evening on Monday with the loss of
daytime heating. While another day of showers and storms is
forecast on Tuesday, model bulk shear values looks to remain
below 30 knots. Therefore, severe weather is not anticipated at
this time. However, this will be monitored in case trends change.
Another concern early this next week will be flooding. With
saturated soils due to recent rainfall, any additional rain may
lead to nuisance to minor flooding, especially in urban and low-
lying areas. Remember, Turn Around, Don`t Drown if you encounter
flooded roads!

As the upper and surface lows move northeast of the local area
Tuesday night, chances of showers and storms dwindle to between
10-20% by late Tuesday night (mainly east of I-65). As for
temperatures, expect highs in the lower to mid 70s both Monday and
Tuesday, with lows in the upper 50s to lower 60s each night.

&&

.LONG TERM...
(Wednesday through Sunday)
Issued at 920 PM CDT Sun May 11 2025

The persistent upper low will finally shift to our northeast and
upper ridging will become the more dominant influence on our
weather locally. H85 temps will begin to increase Wednesday night
and we will see a transition to a warmer but briefly dry airmass.
Thursday will feature dry conditions with highs in the upper 80s
to perhaps lower 90s in some locations. From here our attention
turns to the late week and weekend time period, where a series of
upper waves will be responsible for multiple days of severe
weather across portions of the MidWest and potentially into the
Southeast. High pressure over the western Atlantic will keep warm
tropical air flowing north into these regions as the
aforementioned upper waves push a cold front southeast, nearing
the Tennessee Valley over the weekend. There is low confidence
regarding the evolution of these systems and where the front will
line up each day. We have high confidence that we will be in a
warm and unstable airmass for several days in the late week
period, but the amount of forcing for strong to severe storms
remains in question. Regardless, we will have to monitor this
period for severe storms as well as dangerous heat as heat indices
could reach the mid 90s Thursday and Friday. Keep an eye on
forecast updates throughout the week.

&&

.AVIATION...
(06Z TAFS)
Issued at 1154 PM CDT Sun May 11 2025

Bands of -SHRA/TSRA will continue to track north from central
Alabama into the Tennessee Valley overnight. This may prompt
reductions to MVFR to IFR conditions due to reduced visibilities
and ceilings by 08-09z. Low MVFR ceilings will persist through the
day on Monday, with another round of SHRA/TSRA looking more
likely during the mid afternoon to early evening window. Have
maintained the PROB30 to address this for now between 19-01z at
both terminals. AWWs and amendments may be needed during this late
day window.

&&

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

$$

NEAR TERM...AMP.24
SHORT TERM....26
LONG TERM....25
AVIATION...AMP