Hail in Alabama, April 19, 2024

Area Forecast Discussion
National Weather Service Huntsville AL
606 AM CDT Fri Apr 19 2024

...New AVIATION...

.NEAR TERM...
(Today)
Issued at 233 AM CDT Fri Apr 19 2024

We are currently monitoring a line of stronger storms that was
approaching the Memphis metro area as of 2 AM Friday morning.
Originally initiating on a cold front extending from a surface low
over Ohio, the line of storms should outpace the front in the
early morning hours, leading to a gradual weakening trend. As we
progress throughout the day, we will need to be aware of two focus
areas: the remnant outflow boundary from the nocturnal storms and
additional storms that could form along the cold front pushing
through the Tennessee Valley this afternoon.

There is very low confidence in any severe storms from the
remnant outflow boundary pushing through the area. The greater
chances will be as the true cold front pushes through the TN
Valley this afternoon, which will align with peak diurnal heating.
As a result, there will be a window from roughly 10 AM to 4 PM
when surface-based instability aligns with the potential for
additional convection initiation along the cold front. SBCAPE
values approaching 2000 J/kg and mid-level lapse rates approaching
7 C/km will allow for a damaging wind gust and hail threat with
any stronger cells. More favorable 0-6km shear looks to be behind
the better CAPE values this afternoon, so disorganized pulse-like
clusters is the anticipated storm mode. Zonal flow aloft will also
limit dynamic support for more widespread strong to severe storms.
The primary area of concern extends from Cullman county up through
Jackson county in AL, aligning fairly well with the Marginal risk
area from SPC.

High temperatures today peak in the low to mid 70s for northwest
AL where showers and storms start sooner, while portions of
northeast AL may reach 80 with some periods of sun peeking through
an otherwise overcast sky.

&&

.SHORT TERM...
(Tonight through Monday)
Issued at 233 AM CDT Fri Apr 19 2024

The cold front is forecast to push through the TN Valley fully
this evening as it tracks toward the Gulf Coast. Despite drier
mid-level air surging in behind the front, some lower level
moisture will linger through tonight. Dew points in the 40s move
in Saturday morning, but before then, the forecast will need to
keep track of some isentropic upglide that could lead to lingering
drizzle overnight. Zonal flow persists aloft and weak surface
high pressure starts seeping from Canada down to the southern
Plains. Just ahead of this surface high, a weak upper-level
shortwave trough will traverse the Southern US states. Another
round of showers with a few thunderstorms (40-60% chance) will
move into the area Saturday afternoon and exit the region Sunday
afternoon.

While some cold air advection behind the front will cause high
temperatures on Saturday to peak in the mid 60s to low 70s, some
areas may struggle to get above 60 on Sunday! Overnight lows drop
to the 40s Saturday night and then potentially the upper 30s
Sunday night as the modified Canadian air mass settles over the
Lower Mississippi Valley.

&&

.LONG TERM...
(Monday night through Thursday)
Issued at 233 AM CDT Fri Apr 19 2024

For how volatile late-April can be for our area, next week looks
pretty pleasant, relatively speaking. Surface high pressure will
keep higher rain chances at bay and high temperatures in the
mid-70s. A few things to monitor will be a shortwave trough
digging into the Great Lakes region with an attendant surface low
that may drag a cold front into the South. For now, low rain
chances (20-30%) are in the forecast for late Tuesday into
Wednesday. The greatest potential for rain with this system will
stay farther north, but that could change if the trough digs
farther south. The second feature to watch is a longwave trough
that will set up over the Western US late next week. This may lead
to ridging and warmer temperatures over the Southeast in addition
to sending several impulses through the area, which would lead to
multiple periods of showers and thunderstorms next weekend.

&&

.AVIATION...
(12Z TAFS)
Issued at 606 AM CDT Fri Apr 19 2024

An area of severe storms is moving south of MSL this morning and
should miss HSV. Additional development along this segment will be
the primary convective concern for both terminals today. Low
chance (<20%) of additional storms impacting both terminals this
afternoon, with higher confidence east of both terminals. IFR to
low end MVFR ceilings persist with a stratus deck for today before
gradually lifting to MVFR this evening and VFR late tonight. There
is a low chance for light rain/drizzle this evening, but something
to be mindful of, as lower ceilings may continue longer than
forecast.

&&

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

NEAR TERM...30
SHORT TERM....30
LONG TERM....30
AVIATION...30