Area Forecast Discussion
Issued by NWS Huntsville, AL

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FXUS64 KHUN 141950
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
250 PM CDT Thu Mar 14 2024

...New NEAR TERM, SHORT TERM...

.NEAR TERM...
(Tonight through Friday Morning)
Issued at 250 PM CDT Thu Mar 14 2024

Upper level ridging becomes more zonal through Friday as an upper
shortwave trough traverses the Midwest. Models indicate a few
upper shortwaves will move along the flow over the Tennessee
Valley late tonight through Friday. At the surface, a cold front
will gradually make its way over the region through the day on
Friday as well. As for our area, chances for showers and storms
will ramp up this evening as the aforementioned surface front
approaches. Low to medium chances for showers and storms are
forecast mainly along and west of I-65 through this evening, with
high chances area-wide late tonight through mid-morning Friday.

CAMs earlier today were fairly optimistic about the potential for
strong to severe storms tonight into Friday morning. SBCAPE
values were shown to range between 200-600 J/kg (higher over NW
AL), with some showing upwards of 700 J/kg. Bulk shear values
exceed 30 knots, and even increase to between 40-50 knots by
Friday morning. Furthermore, 0-3 km SRH values generally range
between 100-250 m2/s2. Much of these ingredients look most
favorable west of I-65 as well. However, the latest run of the
HRRR isn`t quite as optimistic that we`ll see much in the way of
severe weather. Regardless, this will be monitored through this
evening and overnight. The main question will be whether the CIN
present (capping inversion) is strong enough to inhibit severe
storm development. Overall, the Storm Prediction Center has our
entire area outlooked in a Marginal Risk of severe storms tonight
and into tomorrow. Make sure to have multiple ways to receive
warning information (especially ones that will wake you up!).

As for timing, Hi-Res model guidance has come into better
agreement today with regards to timing of the main line of showers
and storms tonight. Guidance shows these moving into northwest
Alabama between 2-3AM and progressing from northwest to southeast,
with the severe threat largely coming to an end around 10AM.
Lingering showers/storms are then possible into the afternoon.

Additionally, showers and storms will likely be efficeint
rainfall producers. PWATs over northwest Alabama are shown to
increase to between 1.5-1.7 inches late tonight into early Friday,
which is well above the 90th percentile of Sounding Climatology
for BMX. Forecast storm total rainfall ranges between 1.5-3.0
inches along and west of I-65 and between 1.0-1.5 east of I-65.
Since we haven`t seen a lot of rain in the days leading up to this
event, widespread flash flooding is not anticpated and there are
no Flood Watches in effect. However, at least minor flooding will
be possible, especially west of I-65. The Weather Prediction
Center has outlooked most of our local area in a Slight Risk of
excessive rainfall. Turn around, don`t drown if you encounter a
flooded road while driving!

&&

.SHORT TERM...
(Friday Afternoon through Saturday Night)
Issued at 250 PM CDT Thu Mar 14 2024

After the severe and flooding threats come to an end between mid
to late Friday morning, medium chances (40-60%) of lingering
showers and embedded thunderstorms (non-severe) will be possible
through the remainder of the afternoon. Dry weather will then
return to the Tennessee Valley by Friday night and will persist
through Saturday night. With the passage of the aforementioned
storm system, cooler tempearturs are expected. Highs Saturday will
top out in the upper 60s to around 70 degrees, with lows
decreasing to be in the mid to upper 40s Saturday night. Much
colder weather is on the way for early next week, which is
discussed below.

&&

.LONG TERM...
(Sunday through Wednesday)
Issued at 318 AM CDT Thu Mar 14 2024

[250PM UPDATE] - Not too much has changed with regards to the
long term period. After low chances of rain (10-20%) generally
along and south of the Tennessee River Sunday morning, no rain is
anticipated through at least midweek. A reinforcing surface cold
front will traverse the region on Sunday as well, bringing much
cooler temperatures and breezy conditions to the area for early
next week. Temperatures Monday night may dip into the mid to upper
20s, with wind chills in the lower 20s early Tuesday morning!
Stay tuned!

Lingering impacts will be felt on Sunday from the cold front
passage on Friday. The front will be well south of us, however a
shortwave propagating NE along the boundary will support low rain
chances (10-25%) Sunday evening with dry conditions developing
overnight. Further, a secondary dry cold front is also forecast to
pass through our area Sunday during the day, this will have a
significant impact on temperatures through the duration of the
long term.

Post frontal clouds should clear overnight Sunday with mostly
clear conditions continuing through the long term period.
Fortunately these sunny conditions will be met with much cooler
post frontal temperatures. The passage of the cold front on Sunday
will once again usher in much colder and drier continental air.
Monday afternoon highs will top out in the mid 50s with overnight
lows plunging into the upper 20s and lower 30s. While overnight
conditions look to be clear, winds are currently forecast to
remain elevated from the NW, this could limit our frost potential.
Conversely, this will create morning wind chills Tuesday morning
a few degrees cooler in the low to mid 20s. Fortunately we will
warm up quickly through the week with each day and night warmer
than the last with highs will be back in the 60s by Wednesday.

&&

.AVIATION...
(18Z TAFS)
Issued at 1242 PM CDT Thu Mar 14 2024

VFR conditions will prevail through the rest of this afternoon.
Cloud cover will increase later this afternoon and into the
evening ahead of our next storm system. Medium to high chances of
showers (60-90%) will overspread the local area late tonight into
early Friday morning and persist through early Friday afternoon.
This will bring reductions in VIS in the heavier showers as well
as lowering CIGs to IFR by Friday morning. Some strong to severe
storms are possible as well, bringing the threat of damaging
winds, hail, and frequent lightning. Outside of any storms, winds
will generally be from the south/southwest around 10-15 knots
(gusts up to around 20 knots). LLWS may be a concern from around
9Z through about 12Z, but did not include in the TAFs at this
time. This will be reassessed for the next update.

&&

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

$$

NEAR TERM...26
SHORT TERM....26
LONG TERM....26/RAD
AVIATION...26


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