176
FXUS64 KTSA 211633
AFDTSA

Area Forecast Discussion
National Weather Service Tulsa OK
1133 AM CDT Sat Sep 21 2024

...New SHORT TERM...

.SHORT TERM...
(The rest of today )
Issued at 1128 AM CDT Sat Sep 21 2024

Morning temperature and dewpoint trends are tracking similar to
yesterday with slightly drier trends across portions of NE OK.
Regional RAOBS support forecast high temps in the mid 90s to
near 100 degrees across the region and expectation is dewpoints
remain high enough to yield heat index values around 105 degrees
by mid afternoon. A head advisory has been posted to reflect this
scenario. Well defined outflow boundary from morning storms across
SW MO currently extends across Madison into eastern Benton
counties. This boundary may mix slightly eastward through the
afternoon but will remain a potential focus for showers and storms
later this afternoon. The current forecast has these trends shown
and the update will incorporate observed trends and make only
minor adjustments.

&&

.LONG TERM...
(Tonight through Friday)
Issued at 150 AM CDT Sat Sep 21 2024

During the day Sunday the upper level high that has dominated the
weather of late will weaken and shift south as a positively tilted
trough moves into the region, with the upper level low center
moving into Kansas. Showers and storms will increase across the
area as upper level diffluence spreads over the warm and humid
atmosphere (850-500 hPa specific humidity near the 99th percentile
for this time of year). Then, the surface cold front will move
through during the afternoon and evening. Storm activity will
focus near and behind this boundary, resulting in wet conditions
for many Sunday afternoon into Monday morning. Although this will
not be a classic severe setup, there will be sufficient
instability, shear, and forcing for a marginal threat of a few
borderline severe storms. In terms of rainfall, guidance leans
towards a more modest event, with most areas seeing around a half
inch or rain or less.

High temperature forecasts Sunday are uncertain and will be
dictated by the exact frontal timing. Model guidance is in good
agreement that Monday will be quite cool, with most areas in the
low to mid 70s. Rain chances will gradually diminish from west to
east during the day.

The forecast begins to become more uncertain midweek as the initial
trough interacts with a second reinforcing shortwave digging into
its rear. Cluster analysis shows about a 40% chance that both upper
level lows will consolidate into one trough that stays over or just
west of the area. In this outcome we would stay much cooler and
possibly showery, with the chance of more significant rains
returning towards the weekend. Another 40% of guidance sends the
trough east of the area, which would result in ridging returning,
and warmer and drier conditions. The last 20% of guidance shows
something in between these outcomes. So there is still no
preferred solution for the middle to end of next week, but any of
these outcomes will still allow for much more fall-like weather
than we have been seeing lately. Bumped NBM temperatures up a bit
to try to get closer to the median of these two different model
camps for Wednesday to Thursday.

&&

.AVIATION...
(12Z TAFS)
Issued at 537 AM CDT Sat Sep 21 2024

VFR conditions should prevail through the period. The best chances
for on station shower/thunderstorm impacts at any of the sites
look to hold off until after 22/12Z in association with the cold
front, but there is enough of a chance at BVO toward the end of
the period to include a PROB30 mention featuring MVFR visibility
potential. Southerly wind gusts from 15 to 20 kts remain expected
late morning into the afternoon at the NE OK terminals, with
prevailing speeds at all sites expected to be at 10 kts or less.

&&

.PRELIMINARY POINT TEMPS/POPS...
TUL   98  75  88  60 /  20  20  50  70
FSM   98  75  93  69 /  10  10  10  30
MLC   98  74  92  61 /   0  10  30  60
BVO   98  70  85  55 /  20  30  70  70
FYV   94  71  88  63 /  20  20  30  50
BYV   92  70  89  65 /  30  20  40  50
MKO   96  74  91  60 /  10  10  30  60
MIO   96  71  87  58 /  20  20  50  70
F10   98  74  91  59 /  10  10  30  60
HHW   97  73  93  67 /   0  10   0  20

&&

.TSA WATCHES/WARNINGS/ADVISORIES...
OK...Heat Advisory until 6 PM CDT this evening for OKZ049-053>057-
     059>062-064>068-070>076.

AR...Heat Advisory until 6 PM CDT this evening for ARZ019-020-029.

&&

$$

SHORT TERM...07
LONG TERM....06
AVIATION...22