Siloam Springs, Arkansas 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

748
FXUS64 KTSA 210114
AFDTSA

Area Forecast Discussion
National Weather Service Tulsa OK
814 PM CDT Fri Sep 20 2024

...New UPDATE...

.UPDATE...
Issued at 809 PM CDT Fri Sep 20 2024

Some earlier, isolated convection was noted over the terrain areas
of western AR and southeast OK, but has since dissipated. An
outflow boundary associated with a cluster of storms moving across
southern KS may eventually flirt with areas along the border
resulting in continued non-zero chance of a shower there
overnight. Otherwise expectation is for the upper ridge to hold
firm overnight and keep any notable activity well to the north.
Thus the current forecast of a slight chance along OK/KS border
looks reasonable, with very warm overnight lows for the time of
year.

&&

.SHORT TERM...
(Through tonight)
Issued at 218 PM CDT Fri Sep 20 2024

Latest surface analysis from the region shows a weak/diffused
frontal boundary hovering just north of the KS/OK border. Daytime
heating helped initiate elevated convection earlier this morning in
far northeast OK, near the KS border, which dropped anywhere from
a few hundredths to a couple of tenths of an inch of rain.
Additional convection development remains possible (10-20%) across
the far northern tier of the forecast area, including portions of
northwest AR, late this afternoon into early this evening as the
weak frontal boundary continues to lift northward. However, the
lingering cloud cover and convection may inhibit this development.
Nevertheless, if storms are able to develop, coverage and
intensity of the storms should be considerably lower than what
occurred yesterday afternoon/evening.

Forecast temperatures thus far today havent really materialized
north of the I-40 corridor due to the aforementioned
showers/storms from earlier as well as thick mid/upper level cloud
cover that has stuck around. Was confident enough to drop the
Heat Advisory from Pawnee, Osage, Washington, Nowata, and Craig
counties in OK as heat indices should remain just at or below
advisory criteria (<105F) through the rest of the afternoon. Have
maintained the rest of the Heat Advisory through 8 PM this
evening. For this evening and overnight tonight, plan for another
unseasonably warm/sultry night with overnight lows ranging from
the mid-upper 70s for most locations; temperatures will be about
15 degrees above average for late September.

Mejia

&&

.LONG TERM...
(Tomorrow through Friday)
Issued at 218 PM CDT Fri Sep 20 2024

Potent mid/upper-level ridging over the Plains will hold strong
through Saturday before weakening and shifting southward on Sunday
as an upper-level trough ejects off the Rockies. Although
temperatures are forecast to soar into the mid-upper 90s to near
100F in spots again on Saturday afternoon, dewpoint temperatures
are not expected to be quite as high. These lower dewpoints should
keep heat indices below Heat Advisory criteria for the most part,
though criteria might be reached for a couple of hours for some
locations (Tulsa metro, AR River Valley). Will forgo issuing
another Heat Advisory for now, but conditions and guidance will
continue to be reevaluated over the next 12 hours.

Cooler temperatures are forecast to begin on Sunday as a modest
autumn-like cold front approaches from the north. Although the
frontal boundary is expected to arrive during the afternoon and
evening hours on Sunday, thick cloud cover ahead of the
approaching front will keep temperatures cooler than previous days
with afternoon temperatures still reaching the low-mid 90s
(perhaps upper 80s along the OK/KS border). Additionally, shower
and thunderstorm chances will increase along and ahead of the
front on Sunday. Despite decent shear and low-level moisture in
place as the front approaches, lapse rates and instability look to
be marginal at this time, though sufficient enough to produce a
few strong to marginally severe thunderstorms. Best support for
strong/severe storms will be along and north of the I-44 corridor
during the afternoon and evening, ahead of the advancing cold
front. The main hazards with any organized thunderstorm activity
will be damaging wind gusts, small hail, and locally heavy
rainfall that may lead to flooding.

The cold front will push through the forecast area by late Sunday
night or Monday morning and will result in unseasonably cool
temperatures through the middle part of next week. Precipitation
chances may linger behind the front through at least Monday
morning, drying out west-to-east through the daytime. Another
opportunity for showers and isolated thunderstorms will arrive
late Tuesday into Wednesday as the aforementioned trough
axis/upper low swings through and east of the forecast area,
though global models/ensembles still differ with timing and
location of when this happens. There is even less forecast
confidence on what transpires toward the latter half of the
workweek next week as model synoptic solutions really diverge.
However, consensus in guidance keeps temperatures near seasonal
average through the end of the week.

Mejia

&&

.AVIATION...
(00Z TAFS)
Issued at 627 PM CDT Fri Sep 20 2024

Light and variable winds are expected overnight with light south
winds into Saturday. A few isolated showers/storms will be
possible across northwest Arkansas, mainly Saturday afternoon,
however precipitation chances appear too low to mention at this
time. VFR conditions are expected through the forecast period with
only passing mid/high clouds.

&&

.PRELIMINARY POINT TEMPS/POPS...
TUL   76  98  75  90 /  10  10  20  40
FSM   75  97  75  93 /   0  10   0  10
MLC   75  98  74  94 /   0   0   0  10
BVO   73  99  70  88 /  10  10  20  60
FYV   73  94  72  89 /  20  20  10  30
BYV   72  94  71  90 /  20  40  20  30
MKO   75  96  75  92 /   0  10  10  20
MIO   74  96  72  89 /  20  20  30  50
F10   74  98  73  92 /   0   0   0  30
HHW   72  96  72  93 /   0   0   0   0

&&

.TSA WATCHES/WARNINGS/ADVISORIES...
OK...None.
AR...None.
&&

$$

SHORT TERM...14
LONG TERM....67
AVIATION...12