406
FXUS64 KHUN 081800
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
100 PM CDT Mon Jun 8 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 1109 AM CDT Mon Jun 8 2026

 - Excessive rainfall and life-threatening flash flood risk
   will persist through Tuesday.

 - A Flood Watch is in effect until 8 PM today for much of north
   AL and all of southern middle TN.

 - Heat Risk increases by late this week. Heat index values in the
   middle 90s to around 100 degrees Wednesday through Saturday.

&&

.NEAR TERM...
(Rest of Today and Tonight)
Issued at 1109 AM CDT Mon Jun 8 2026

A significant and potentially life-threatening flash flood threat
continues across the Tennessee Valley today, particularly across
portions of northeast Alabama where widespread flooding is
already ongoing from the 2-8 inches of heavy rainfall we received
yesterday.

Looking at the big picture, an approaching shortwave trough will
provide additional synoptic-scale lift across the region today.
Combined with abnormally high atmospheric moisture depicted by
PWAT values near 2.2 inches and moderate instability with SBCAPE
values between 2000 and 2500 J/kg, conditions will remain
favorable for numerous showers and thunderstorms capable of
producing extremely heavy rainfall rates.

The primary concern today is not necessarily the exact rainfall
amounts, but rather how quickly additional rainfall will translate
into runoff. Many locations across northern Alabama and southern
middle TN received between 2 and 8 inches of rainfall yesterday,
leaving soils saturated and most rivers/streams either elevated or
overflowing their banks. As a result, virtually any rainfall that
develops today will run off efficiently, leading to rapid water
rises and the potential for life-threatening flash flooding.
Convectively enhanced rainfall rates could exceed 2 to 3 inches
per hour at times within stronger storms. Even brief periods of
heavy rainfall could quickly overwhelm drainage systems, inundate
roadways, and cause additional dangerous rises on creeks and
streams. Residents across the Tennessee Valley should remain
weather aware throughout the day and treat all Flash Flood
Warnings as life-threatening situations. Use extreme caution if
driving through rainfall, obey all road closures, and never
attempt to drive through flooded roadways!

Rain should come to an end from west to east late this evening
with a brief period of dry conditions before low rain chances
start to creep back in across norther portions of the forecast
area before sunrise. Please remember that any areas that flood
today will likely remain that way overnight, leading to an
increased threat to life due to lower visibility.

&&

.SHORT TERM...
(Tuesday through Wednesday)
Issued at 1109 AM CDT Mon Jun 8 2026

The aforementioned upper trough axis will begin to shift east of
the area on Tuesday, resulting in low to medium chances for
showers and storms particularly for areas east of I-65. With PWATs
still near 2", additional heavy rainfall could worsen flood
conditions. Due to the more scattered nature of these storms, the
Flood Watch was not extended through Tuesday at this time but
forecast trends will be monitored closely. Convection will become
more diurnally driven during the mid-week period with rain
chances capping near 30% Wednesday afternoon. The threat will
begin to shift more toward dangerous heat during this time with
afternoon heat indices approaching 100 degrees. Be sure to keep
heat safety in mind for any outdoor plans later this week!

&&

.LONG TERM...
(Wednesday night through Sunday)
Issued at 1209 AM CDT Mon Jun 8 2026

The ridge across much of the southern and eastern CONUS will be
dampened as a wave of energy rounds the base of a trough in
southern Canada on Thursday and furthermore on Friday. On Friday,
the associated sfc low will be north of the Great Lakes, but the
cold front will drape down through the OH Valley and back into the
Mid MS Valley. Some models have the cold front dipping toes into
the TN Valley Friday night, while others are suggesting it stalls
out north of us and never makes it in. Will stick with guidance
for now with this, and that brings a medium chance (60%) of
showers and thunderstorms Friday. Otherwise, we will be under high
pressure throughout the rest of the extended forecast, but it
won`t feel like it. We`ll be trapped in with plenty of moisture
for diurnally driven convection each day (low to medium chances
20-50%).

We will also turn up the heat as temps reach the upper 80s/lower
90s on Thursday through Saturday and just in the upper 80s on
Sunday. It is important to note that this set up will also push
the heat index values into the upper 90s/lower 100s Thursday
through Saturday. Will monitor trends, but right now values are
below Heat Advisory Criteria. Regardless though, you will need to
practice heat safety because we do not feel acclimated to the high
heat and humidity for this long quite yet, so ensure that you
stay hydrated and slow down to prevent heat related illnesses.

&&

.AVIATION...
(18Z TAFS)
Issued at 100 PM CDT Mon Jun 8 2026

MVFR to IFR conditions are forecast through the afternoon into
early evening hours as heavy rain and thunderstorms move across
the area that will result in poor vsbys during heavier showers.
This activity should clear the area late this evening making way
for VFR conditions overnight. IFR to LIFR cigs are forecast to
return early Tuesday morning with low to medium chances for rain
and storms.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...Flood Watch until 8 PM CDT this evening for ALZ001-005>010-016.

TN...Flood Watch until 8 PM CDT this evening for TNZ076-096-097.

&&

$$

NEAR TERM...25
SHORT TERM....25
LONG TERM....JMS
AVIATION...25