512
FXUS64 KHUN 051659
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
1159 AM CDT Wed Jun 5 2024

...New AVIATION...

.NEAR TERM...
(Rest of Today)
Issued at 948 AM CDT Wed Jun 5 2024

Yet another shortwave trough will ripple across the Tennessee
Valley today bringing medium to high chances of showers and
thunderstorms (60-80%) once again. This morning, a few clusters of
showers have formed along residual outflow boundaries from
convection yesterday. It will be these remnant boundaries that
will likely be a focus for convection again later today,
especially this afternoon when some mid/upper level support
arrives from the shortwave and the amplifying trough. Given the
moist environment (PWATs ~ 1.9"), locally heavy rainfall/downpours
will be the main impact with this convection in addition to
lightning. Poor lapse rates (mid-level values near moist
adiabatic) will hinder updrafts, with SBCAPE values being very
modest (up to 1000 J/kg). Shear values may be high enough
(especially by late this afternoon and evening) to allow for a few
multicell clusters in addition to pulse storms, with localized
gusty winds being the other threat. Only minor tweaks made to the
forecast based on the lastest obs/trends.

&&

.SHORT TERM...
(Tonight through Friday night)
Issued at 330 AM CDT Wed Jun 5 2024

Will maintain 60-80% chances for rain and storms this evening, but
they will come to an end from west to east during the morning as
a cold front pushes drier air into the area. Overnight lows will
be in the mid to upper 60s with a low chance for patchy fog if
clouds clear the area quicker than currently forecast. Dry and
slightly cooler temperatures will follow for the remainder of the
short term period as high pressure becomes dominant and the
beginning of an extended period of northwest flow aloft begins.
Afternoon highs will drop from the mid to upper 80s on Thursday to
upper 70s/lower 80s Friday, with lows falling down into the upper
50s in the higher terrain on Friday night.

&&

.LONG TERM...
(Saturday through Tuesday)
Issued at 330 AM CDT Wed Jun 5 2024

Looks like we will be stuck in this northwesterly flow pattern
through the extended forecast. An upper low straddling Ontario and
Quebec will be anchored there and a few shortwaves will round the
trough providing us chances of rain through Monday. The associated
sfc low will have a cold front extending through the OH Valley and
back into the Lower MS Valley that will head into the TN Valley and
Southeast this weekend. Ahead of these features, cloud cover will
increase on Saturday and low chances (20-30%) of showers and
thunderstorms will return. Coverage will increase to ~40% on Sunday
as the front draws near. During this time, a lobe of energy will
phase with the upper level trough, shifting it eastward. The GFS is
the most progressive with this and wants to bring in ridging by
Monday. Will wait for better model consensus and instead stick with
the NBM on keeping low chance of POPs in through Monday. Cooler and
drier air will filter in behind the front, providing drier conditions
and more sunshine on Tuesday. Daytime highs through the extended
will be near or slightly below seasonable values, staying in the
upper 70s to lower 80s. Lows on the other hand will remain warm
through the weekend and become more seasonable behind the front
returning to the lower 60s.

&&

.AVIATION...
(18Z TAFS)
Issued at 1159 AM CDT Wed Jun 5 2024

SHRA/TSRA will redevelop late in the day into the evening hours as
a shortwave trough swings across the region. At times these storms
may produce localized MVFR conditions due to reduced visibilities
and ceilings. AWWs and amendments may be needed should a storm
impact either terminal. Have handled this with TEMPOs and/or
PROB30 groups for now. This activity will gradually dissipate from
west to east late in the period as they push eastward into
Georgia.

&&

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

$$

NEAR TERM...AMP.24
SHORT TERM....25
LONG TERM....JMS
AVIATION...AMP.24