988
FXUS64 KHUN 120243
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
943 PM CDT Tue Jun 11 2024

...New NEAR TERM...

.NEAR TERM...
(Rest of tonight)
Issued at 942 PM CDT Tue Jun 11 2024

Winds have decoupled in many areas in northwestern Alabama. Expect
this to occur in southern middle Tennessee, as a weak trough axis
at the surface moves southeast this evening. As this trough axis
shifts further southeast, it should re-enforce very weak advection
of slightly drier air into the area as it does so. Models do move
this feature back to the north during the morning hours on Wednesday,
but not before then. Some thin high clouds can seen in satellite
imagery moving northeast through the area, but they are moving
quickly northeast and are very thin and high in nature. We are not
expecting them to have much impact. This should have little impact
on radiational cooling conditions this evening given light winds
already, which should continue. Some scattered lower clouds could
affect portions of northeastern Alabama towards and after daybreak.
However, they should remain scattered at best until around 7 or 8
AM, when they could become more widespread.

Temperatures have already dropped into the lower to mid 60s in
many locations. The exceptions to this are mainly in the Quad
cities areas and locations that still have northerly winds around
5 mph in north central Alabama. Given some dewpoint depressions
are already 5 or 6 degrees and good radiational cooling is
expected overnight, introduced patchy areas of fog after 2 or 3
AM into the forecast. This could become areas of fog briefly
around daybreak, mainly west of the I-65 corridor and in sheltered
valley locations. Not expecting dense fog  at this time. Overall
lowered temperatures and dewpoints slightly overnight. Lows should
likely drop into the 51 to 54 degree range west of the I-65
corridor and in a few sheltered valley spots further east.
Otherwise, lows in the mid to upper 50s are expected.

&&

.SHORT TERM...
(Wednesday through Friday)
Issued at 327 PM CDT Tue Jun 11 2024

A dry trend should continue for the remainder of the work week, as
the airmass in the aformentioned surface high moderates from a
strong June sun. Highs on Wednesday should rise into the
mid/upper 80s under generally sunny skies. A warming trend will
continue as we near the upcoming weekend, with lows Wed night in
the lower 60s. Summer conditions return Thursday with highs rising
into lower 90s. Even warmer temperatures are forecast Friday, with
highs heating into the low/mid 90s.

&&

.LONG TERM...
(Friday night through Monday)
Issued at 327 PM CDT Tue Jun 11 2024

Not many changes made with the extended period. A surface high
over the eastern CONUS will stagnate even more as we go into the
weekend. Strong and warm upper ridging will also build over the
region, with 500mb heights rising to and above 590 decameters from
Saturday into early next week. This and more sun than clouds will
likely create a rather hot weekend. After lows Friday night in the
mid 60s to lower 70s, highs Sat will soar into the mid 90s. Even
warmer Sunday with highs in the mid/upper 90s. Heat Index values
on Sat should rise into the mid 90s to 100, and upper 90s to 105
on Sun. The 105 readings were spotty over parts of NW Alabama.

Previous discussion 408 AM...

The center of the mid-level high is predicted to become centered
directly across the TN Valley by Saturday, with the warming trend
continuing as mostly sunny skies during the afternoon will support
highs in the mid 90s on Friday and mid/upper 90s on Saturday (but
roughly 5-10 degrees cooler both days atop the Cumberland
Plateau). Unfortunately, it appears as if low-level moisture will
begin to pool ahead of a weakening cold front that will drift
southward into the TN Valley before stalling on Friday
afternoon/evening as the parent surface low ejects northeastward
across Quebec, and the increase in dewpoints will result in heat
indices in the 95-99F range Friday and 98-102F range Saturday.

The 500-mb high will begin to shift east-northeastward into the
NC/VA vicinity on Sunday and Monday, allowing for a gradual
increase in deep-layer SSE flow across the TN Valley by early next
week. Although this configuration will eventually contribute to
gradual moistening of the atmospheric column (and a subsequent
increase in clouds and showers) this will likely not occur by
Sunday, and highs are forecast to reach the m-u 90s, with heat
index values in the 100-105F range. We have indicated a low
(20-30%) POP for showers and thunderstorms returning to most of
the region Sunday night/Monday, and have indicated lower afternoon
temps on Monday as a result of this. However, if the subtropical
ridge remains more influential (as indicated by several global
models), then the hot/dry pattern may continue for several
additional days next week.

&&

.AVIATION...
(00Z TAFS)
Issued at 542 PM CDT Tue Jun 11 2024

VFR conditions continue through the TAF period at both KMSL and
KHSV with light, northerly winds.

&&

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

$$

NEAR TERM...KTW
SHORT TERM....RSB
LONG TERM....70
AVIATION...HC