Flash Flood Warning 5, NWS Huntsville, AL

Area Forecast Discussion
National Weather Service Huntsville AL
1046 AM CDT Sat Mar 15 2025

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

.NEAR TERM...
(Today and Tonight)
Issued at 1045 AM CDT Sat Mar 15 2025

A significant severe weather event is forecast to develop later
today. Please make sure you have your severe weather safety plan in
place this morning before conditions begin to deteriorate.

Satellite imagery shows two low pressure circulations with the first
over the upper Midwest and the second over Texas with a cold front
stretching between the two systems. There is a brief lull in the
severe activity this morning after several strong to severe storms
pushed through during the predawn hours. Heavy rainfall overnight
combined with training storms in northeast Alabama this morning has
locally increased the flooding threat, especially given that more
heavy rainfall is expected later today.

As the low over Texas ejects north and east along the base of the
upper level trough axis, a secondary sfc low will form in Mississippi
late this morning and then lift up through the Tennessee Valley.
Morning soundings from JAN/BMX show a capping inversion near the sfc
with a good amount of instability aloft. In response to the deepening
sfc low, the low level wind fields will rapidly increase allowing
for strong WAA that will ultimately erode the capping inversion.
Once this occurs we should see rapid development along or ahead of
the cold front in Mississippi in the open warm sector. Gradient winds
ahead of the storms are forecast to gust 35 to 40 mph and as a
result the Wind Advisory continues through 1 AM Sunday.

We expect the storms to develop just before lunchtime today and
enter into northwest Alabama by around noon. Initially, discrete
supercells are possible given forecast soundings showing 1500-2000
J/kg of CAPE, 40-50 knots of 0-1 km shear, and very good curvature in
the hodographs. Behind the discrete storms will be a QLCS along or
just ahead of the cold front with embedded supercells likely given
that shear increases and instability is able to recover after the
first wave of storms. All severe hazards are possible with tornadoes,
large hail, and damaging winds all possible.

The storms will quickly progress eastward this afternoon and by this
evening they should gradually weaken as they enter northeast Alabama
due to instability weakening. However, while the severe threat may
decrease the flooding rain threat may increase. Especially as the
heavy rainfall moves over areas that received a few inches of
rainfall this morning across northeast Alabama. Pwats remain high
through this evening (1.5-1.75 inches) indicating high rain rates
throughout this event and the potential for flash flooding. Therefore,
the Flood Watch for flash flooding will continue through 1 AM
Sunday.

&&

.SHORT TERM...
(Sunday through Monday)
Issued at 1045 AM CDT Sat Mar 15 2025

Mid-level trough across the central U.S. will shift eastward on
Sunday across the region Sunday night into Monday morning. Ridging
will build in behind exiting trough for Monday. Lingering precip
chances will accompany the passing of the trough with
thunderstorms not out of the question Sunday morning and afternoon.
Thankfully, primary forcing for any severe weather will have
passed to our east. Highest chances for rainfall of 40%-55% will
remain over our far northeastern counties in AL and southern
middle TN. The local pressure gradient will slacken slightly but
still remain breezy and winds shift to the west to northwest at
10-15 mph gusting 20 mph. Lighter winds are expected for Monday.
Temps will remain mild on Sunday with highs in the low 60s with
temps dropping into the low-30s Sunday night into Monday morning.
That cooler air will continue to filter in for Monday with highs
in the upper 50s to right around 60 degrees under sunny skies.

&&

.LONG TERM...
(Tuesday through Friday)
Issued at 1145 PM CDT Fri Mar 14 2025

On Tuesday, a 5h and 8h ridge will shift east through the TN
valley and southeast. The surface high will also shift into GA
allow warm southwest flow to develop in advance of another
vigorous trough in the Plains. The surface low with this trough
will deepen over the upper Midwest during this time, with an
attendant cold front slicing south from the low reaching middle TN
and north AL by midday or afternoon Wednesday. Fortunately,
moisture return will be short-lived, narrow and limited, with dew
points briefly reaching the lower 50s ahead of the front
Wednesday. Thus, expecting light to moderate showers if anything
with this frontal passage. After highs in the 70s Wednesday, only
50s are expected Thursday with brisk northwest winds following the
frontal passage. Then a quick transient high moves in Thursday
night which may bring temperatures down to flirt with a minor
freeze, but only briefly. Another upper low will plow east-
southeast quickly through the lower MS Valley and Gulf states by
Friday night with a better chance of more substantial showers and
a few thunderstorms.

&&

.AVIATION...
(12Z TAFS)
Issued at 621 AM CDT Sat Mar 15 2025

Initial round of thunderstorms will continue to move through the
region this morning and eventually move out of the area. After
the late morning lull in activity the main system will move
through later in the period. Certainty is high that storms will
impact all the airports, but only medium confidence on the timing
and low confidence on the flight categories during the storms. All
types of severe weather will be possible when strong storms are
near an airport.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...Flood Watch through late tonight for ALZ001>010-016.

     Wind Advisory until 1 AM CDT Sunday for ALZ001>010-016.

TN...Flood Watch through late tonight for TNZ076-096-097.

     Wind Advisory until 1 AM CDT Sunday for TNZ076-096-097.

&&

NEAR TERM...GH
SHORT TERM....KG
LONG TERM....17
AVIATION...99

Preliminary Local Storm Report
National Weather Service Huntsville AL
1055 AM CDT Sat Mar 15 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0850 AM     Non-Tstm Wnd Dmg 4 NE Muscle Shoals      34.79N 87.60W
03/15/2025                   Colbert            AL   911 Call Center

            Trees down in the 300 block of Ford Road.

&&

12

Preliminary Local Storm Report
National Weather Service Huntsville AL
1101 AM CDT Sat Mar 15 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0945 AM     Non-Tstm Wnd Dmg 5 S Killen              34.79N 87.53W
03/15/2025                   Colbert            AL   911 Call Center

            Trees down in the 5000 block of River Road.

&&

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Preliminary Local Storm Report
National Weather Service Huntsville AL
1105 AM CDT Sat Mar 15 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1000 AM     Non-Tstm Wnd Dmg 5 S Killen              34.79N 87.53W
03/15/2025                   Colbert            AL   911 Call Center

            Trees down on Cedar Lane and Old Covered
            Bridge Road.

&&

12