Decatur, Alabama 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

108
FXUS64 KHUN 041707
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
1207 PM CDT Mon May 4 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 1032 AM CDT Mon May 4 2026

 - There is a low to medium chance for severe thunderstorms
   Wednesday afternoon through Wednesday night.

 - Localized flash flooding and damaging winds will be the primary
   threats with the strongest storms, with a low chance of
   marginally severe hail and a tornado or two.

&&

.NEAR TERM...
(Rest of Today and Tonight)
Issued at 1032 AM CDT Mon May 4 2026

Tranquil weather across the Tennessee Valley today as a ridge of
high pressure builds into the area from the west. This will
promote a beautiful early May day and noticeable warm-up as
temperatures will climb into the upper 70s to lower 80s, thanks to
the ample sunshine and breezy southwest winds. These winds will
weaken after sunset and with a clear sky it should be a good night
for radiational cooling. As a result, lows will fall into the
upper 40s to lower 50s along the sheltered valleys of northeast
Alabama and the mid 50s elsewhere.

&&

.SHORT TERM...
(Tuesday through Thursday)
Issued at 1032 AM CDT Mon May 4 2026

High pressure will scoot off to the east of the region on Tuesday
as a broad upper-trough and its associated cold front approaches
the Tennessee Valley from the northwest. Cloud cover will
gradually increase through the day on Tuesday, with some weak lift
creating some low (20-30%) chances for light rain showers in the
late afternoon. Some low to medium chance for rain showers (and a
low chance of a few elevated thunderstorms) will expand overnight
as the boundary sags a little further to the south and east.
Still, precipitation shouldn`t add up to any more than 0.10-0.20"
through 12z Wednesday.

The upper trough over the Great Lakes will amplify on Wednesday,
forcing a front southeast into the region during the afternoon and
overnight hours. Ahead of this front, deep southerly flow will
advect an extremely moist, almost tropical-like air mass as
evidence by PWATs climbing to between 1.8" to 2.1" by the
afternoon. These values would represent new daily max values for
KBMX for the date of May 6th. Thus any convection that can get
going will have a threat for locally heavy rainfall and flash
flooding in areas where training may occur. As a result, WPC has
included the entire Tennessee Valley in a Slight Risk (Level 2/4)
for excessive rainfall.

The main question this far north and east will be how much the
dense cloud cover and morning rain will limit instability. Bulk
shear of around 50-60 kts and low- level shear (aided by a 30-40
LLJ which will be moving NE across the Tennessee Valley during the
18-00z window) will be more than sufficient for organized
convection if it can get going across portions of western to
middle Tennessee during the early afternoon. Current thinking is
that these shear values (assisted by some modest, but appreciable
instability) will favor supercells developing along the front,
but quickly congealing into a linear mode of storms as they move
SE into the Tennessee Valley during the mid/late afternoon into
the evening. This is due to the deep layer flow largely
paralleling the the front as it pivots SE into the area.

All this to say out main threats would be damaging straight-line
winds and a localized flash flooding threat. The wind shear is
fairly unidirectional, but enlongated hodographs with some subtle
curvature in the low-levels would favor a few rotating storms and
a low chance for a tornado or two (mainly in storms that veer to
the right). Low to mid level lapse rates aren`t all that
impressive and for this reason, think the large hail threat is
also fairly low. Storms will weaken after Midnight and clear the
area early Thursday morning, bringing the severe threat to an end.

&&

.LONG TERM...
(Thursday through Sunday)
Issued at 1023 PM CDT Sun May 3 2026

Clouds and rain look to linger into the start of the long term as
the aforementioned cold front pushes to our SE early on Thursday
morning. In its wake, conditions will clear and dry throughout the
day as surface high pressure quickly builds in behind it. The
quick bout of high pressure paired with zonal flow aloft will
allow relatively cooler air to momentarily displace Gulf moisture
keeping temps mild on Thursday and Friday. Highs will range from
the high 60s to low 70s with lows in the 40s and 50s. The brief
bout of dry and clear conditions will come to an end as we head
into the weekend.

Surface high pressure will quickly push off the Atlantic coast as
a surface low pressure system builds in the SW. This will induce SW
flow locally surging moisture and temperatures back towards seasonal
normals. Through the weekend, a weakening mid level low and
associated surface low will pass to our south across the Gulf Coast.
Weak lift associated with this feature paired with Gulf moisture will
support low rain chances (10-20%) on Saturday and Sunday as the
feature passes. No severe weather is forecast.

&&

.AVIATION...
(18Z TAFS)
Issued at 1207 PM CDT Mon May 4 2026

VFR conditions will prevail through the period. Winds will be
gusty out of the SW through this evening, before weakening after
sunset. Winds will again become gusty out of the south late in the
period during the day on Tuesday.

&&

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

$$

NEAR TERM...AMP
SHORT TERM....AMP
LONG TERM....RAD
AVIATION...AMP.24