581 
FXUS64 KTSA 201933
AFDTSA

Area Forecast Discussion
National Weather Service Tulsa OK
233 PM CDT Fri Aug 20 2021

.DISCUSSION...
Hot and humid conditions have returned to eastern Oklahoma today,
with a good chunk of northeast and east central Oklahoma seeing
heat index values from 105 to 110 this afternoon. Still
contemplating adding a couple of counties to the advisory to close
out the afternoon, with Pittsburg, Haskell and Ottawa being the 
top contenders. A prolonged period of heat and humidity, likely to
be the longest so far this summer, is one forecast concern today,
with the other being thunderstorms with locally heavy rain 
potential through at least tomorrow night.

A few thunderstorms are ongoing across parts of western Arkansas
at present, but coverage this afternoon and evening should remain
well below that of the last several days. The next chance for
thunderstorms will arrive in earnest after midnight tonight in
association with a front currently pushing its way through western
Kansas. The front will serve as a focus for development in Kansas
late this evening and into early tomorrow morning, with
thunderstorms expected to dive to the south-southeast into
northeast Oklahoma and far northwest Arkansas toward daybreak.
Residual boundaries will serve as a focus for additional
development tomorrow afternoon and evening, with available 
moisture supportive of locally heavy rainfall and instability 
favorable for isolated strong to severe wind gusts. Hot and humid 
conditions will exist to the south of the convective boundaries, 
with heat index values above 105 likely. A Heat Advisory will not 
be issued with this package for tomorrow given uncertainties in
the northward extent of the heat and humidity.

Moving into Sunday, upper level ridging should expand far enough
northward that the bulk of any thunderstorm development should be
north and east of the forecast area, with only slight chances in
our northeastern fringes. Thereafter, an extended period of dry,
hot and humid conditions will occur, lasting through much, if not
all, of next week. Expect multiple days with at least heat
advisories, if not localized excessive heat warning conditions.
The ridge will flatten some and shift westward through the week, 
which could lead to some isolated thunderstorms and slightly lower
temperatures late in the week. 

&&

.PRELIMINARY POINT TEMPS/POPS...
TUL   78  95  77  97 /  20  40  30  10 
FSM   77  95  76  96 /  10  30  30  20 
MLC   77  94  75  95 /  10  20  20  10 
BVO   74  90  72  95 /  40  30  20  10 
FYV   73  91  71  92 /  20  40  20  20 
BYV   73  91  71  93 /  30  40  20  20 
MKO   74  92  74  94 /  10  30  30  10 
MIO   73  90  72  94 /  50  40  30  10 
F10   74  95  73  96 /  10  30  30  10 
HHW   75  92  74  93 /   0  10  10   0 

&&

.TSA WATCHES/WARNINGS/ADVISORIES...
OK...Heat Advisory until 7 PM CDT this evening for OKZ054>057-059>062-
     064>067-070-071.

AR...None.
&&

$$


LONG TERM....22