070
FXUS64 KHUN 070920
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
420 AM CDT Fri Jun 7 2024

...New NEAR TERM, SHORT TERM, LONG TERM...

.NEAR TERM...
(Today)
Issued at 420 AM CDT Fri Jun 7 2024

Current surface observations suggest that winds have begun to
veer to NW across the TN Valley as a weak cold front progresses
southeastward through the region. Dewpoint temperatures will
likely fall into the u50s-l60s for much of the forecast area by
12Z, and with light winds and lingering cloudiness across the
eastern half of the region expected to dissipate, patchy fog will
continue to develop in our more fog prone locations as temps
descend into the l-m 60s. As for the rest of the day, NNW flow
aloft of 30-40 knots will persist across the region within the
gradient between an upper low shifting eastward across southern
Ontario and a subtropical high that will develop southeastward
from the southern Rockies into TX. At the surface, NW winds will
strengthen later this morning to the east of a ridge (currently
centered across the Ozarks), but with only a minor impact from
thermal advection, abundant insolation this afternoon will yield
highs in the l80s (elevated terrain) and m-u 80s (valley).

&&

.SHORT TERM...
(Tonight through Sunday night)
Issued at 420 AM CDT Fri Jun 7 2024

The center of the surface ridge (discussed above) will migrate
eastward across the TN Valley and into the southern Appalachians
tonight. Although the combination of light/variable winds and
dewpoints in the m50s would normally be optimal for radiational
cooling, high-level clouds will likely begin to spread
southeastward into the region from a thunderstorm complex that
will originate across eastern NE/KS late this afternoon and spread
southeastward through MO before decaying upon reaching the Lower
OH Valley by 12Z Saturday. Thus, we have indicated lows in the
u50s-l60s for most of the region. Latest guidance from the CAMs
and global models suggest that the remnants of the decaying MCS to
our northwest will largely bypass our region to the north late
Saturday morning, but due to some uncertainty regarding the
southward extent of peripheral shower activity, we have included a
very low POP for our southern TN zones between 12-18Z. Otherwise,
mostly sunny skies and a light southwesterly return flow during
the afternoon should boost temps into the u80s-l90s.

By late Saturday afternoon, redevelopment of thunderstorms is
expected across southern MO in the vicinity of a cold front that
will receive a nudge southward as a northern stream vort max
diving across the Upper MS Valley induces development of a weak
surface low over the Lower Great Lakes. This convective regime
will likely expand in coverage Saturday evening, as should spread
east-southeastward with time as mid-level winds back to WNW along
the edge of the subtropical ridge, which will build progressively
eastward into the central Gulf Coast states. However, due to some
uncertainty regarding how far south/east storms will spread early
Sunday morning, we have only included a low-medium (20-30%) POP
for locations north of the TN River. Pending impacts from morning
convection, it appears as if redevelopment of at least scattered
thunderstorms (30-50% coverage) will occur on Sunday afternoon as
a frontal wind shift drifts southward into the forecast area.
Should this occur, mid-level westerly flow of 35-45 knots and
temps in the 85-90F range (supporting CAPE of 2000-3000 J/kg)
could support a few stronger cells capable of producing strong
winds and hail. A few showers and thunderstorms will likely
continue into the evening hours, before gradually dissipating
early Monday morning as a drier airmass is advected into the
region.

&&

.LONG TERM...
(Monday through Thursday)
Issued at 420 AM CDT Fri Jun 7 2024

Forecast uncertainty increases considerably toward the beginning
of next week, as the 0Z suite of global models offers a wide array
of solutions regarding both the upper flow pattern across the
eastern CONUS and eventual position of a cold front that is
expected to drift southward through the region early Monday
morning. Due primarily to uncertainties regarding frontal
location, we have left a low (20-30%) chance POP in the forecast
from Monday-Tuesday, especially as the projected orientation and
proximity of the boundary (and resultant thermal gradient) may
support impacts from additional clusters of thunderstorms that
could originate across OK/AR and spread east-southeastward into
the central Gulf Coast. By the end of the forecast period, a
blocking mid-level ridge is likely to become established across
the TN Valley to the north of a 500-mb trough that will drift
southeastward into the northern Gulf of Mexico before stalling.
This should result in warmer temperatures on Wednesday/Thursday,
along with a transition to mainly isolated thunderstorm activity
during the afternoon hours.

&&

.AVIATION...
(06Z TAFS)
Issued at 1250 AM CDT Fri Jun 7 2024

Few-sct high-based Cu depicted in current satellite imagery will
likely spread southeastward and out of the region by 8Z, with an
extended period of SKC conds anticipated until redevelopment of
diurnal Cu occurs by 16Z. Although this may promote the
development of patchy BR/FG in a few locations btwn 10-13Z, a
gradual increase in NNW flow is expected during this timeframe and
we will not introduce any vsby reductions in the TAFs at this
point. NNW winds will increase to 8G16 kts later this morning,
before becoming lgt/vrbl prior to sunset as a ridge of sfc high
pressure build eastward into the region.

&&

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

&&

$$

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