Area Forecast Discussion
Issued by NWS Huntsville, AL

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000
FXUS64 KHUN 260531
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
1231 AM CDT Tue Mar 26 2024

...New AVIATION...

.NEAR TERM...
(Rest of tonight)
Issued at 1011 PM CDT Mon Mar 25 2024

Showers and a few elevated thunderstorms will continue to spread
northeastward across the TN Valley over the next couple of hours,
within a rapidly strengthening warm/moist advection regime to the
south/east of a mid-level trough lifting northeastward from the MO
Valley. To our west, a broken line of deeper convection continues
to shift eastward along a prefrontal surface trough/remnant
outflow boundary. Both global models and higher- resolution CAMs
suggest that the convective line will become a bit more organized
as it approaches our region, likely in response to the northward
advection of boundary layer dewpoints in the u50s-l60s (and
subsequent increase in CAPE) within a narrow corridor to the
immediate east of the QLCS. Present indications are that the
squall line should reach the AL-MS border around 5-6Z and progress
slowly eastward through sunrise (with intensity not likely to
fluctuate significantly). As SSE winds at the 850-mb level
strengthen (perhaps into the 70-80 knot range) prior to the
passage of the surface trough, downward transfer of higher
momentum air aloft may support locally damaging winds up to 60 MPH
(if not a bit stronger), particularly across the southwestern
portion of the CWFA where the highest dewpoints and greatest
surface-based instability/CAPE will reside.

Otherwise, lightning and locally heavy rainfall will be the
primary impacts from this convective system, but at the current
time we do not see a significant risk for flash flooding due to
the meridional orientation of the line and steady forward
propagation. Regarding the Wind Advisory, we have no plans to
change the current configuration, as SE flow will be sustained
around 35 MPH (with gusts of 40-45 MPH) prior to the passage of
the QLCS. In fact, a few locations in higher terrain may briefly
experience gusts in excess of High Wind Warning criteria.
Fortunately, winds will diminish considerably in the wake of the
surface trough/squall line, and should fall below advisory
criteria for much of the western half of the area prior to 12Z.

&&

.SHORT TERM...
(Tuesday through Thursday)
Issued at 200 PM CDT Mon Mar 25 2024

Tuesday morning, high chances (80-90%) of showers/storms are
forecast to continue impacting areas east of I-65 while medium
chances (40-70%) follow west of I-65. These showers/storms are
forecast to gradually end from west to east as we move into the
afternoon hours and the cold front moves through the Tennessee
Valley. Behind the cold front, dry air is forecast to filter in
under the influence of sfc high pressure from the southern
Plains. This sfc high pressure is forecast to continue moving
southeastward-- reaching the TN Valley by late in the week (more
on this in the long-term section below). During this time, dry
weather is forecast with highs in the 60s and lows in the 40s.

&&

.LONG TERM...
(Thursday night through Sunday)
Issued at 308 AM CDT Mon Mar 25 2024

A strong area of high pressure to the west will shift eastward
across the Tennessee Valley and Deep South Friday into the
upcoming Easter holiday weekend. The end result will be ample
sunshine and a pronounced warming trend as winds veer back to the
south. Dry conditions will also continue as the forecast will
remain devoid of any rain. Highs on Friday will return to the
upper 60s to lower 70s -- with mid/upper 70s forecast both
Saturday and Easter Sunday.

&&

.AVIATION...
(06Z TAFS)
Issued at 1231 AM CDT Tue Mar 26 2024

There have been no significant changes to previous aviation
forecast reasoning, as a prefrontal sfc trough and narrow band of
heavy SHRA/TSRA will continue to shift eastward across the region
during the early morning hours, arriving at MSL arnd 6-8Z and HSV
arnd 8-10Z. This feature will bring IFR visibility as well as
lightning and convective wind gusts up to 50-60 knots, warranting
AWWs. Prior to the passage of the squall line, prevailing sfc flow
will remain from SE at 20G30 kts, with LLWS included due to the
presence of a rapidly strengthening low-level jet. Light rain and
low stratus clouds will continue for ~4 hours in the wake of the
convective band, but winds will subside and shift to SSW reducing
concern for wind shear. Rapid clearing is expected from W-to-E
btwn 16-20Z as winds veer to WSW, with a wind shift to NW
anticipated during the evening hours following the passage of a
cold front.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...

AL...Wind Advisory until 7 AM CDT Tuesday for ALZ001>010-016.

TN...Wind Advisory until 7 AM CDT Tuesday for TNZ076-096-097.

&&

$$

NEAR TERM...70/DD
SHORT TERM...HC
LONG TERM...AMP
AVIATION...70/DD


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