934 
FXUS64 KTSA 280503
AFDTSA

Area Forecast Discussion
National Weather Service Tulsa OK
1203 AM CDT Wed Jul 28 2021

.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
Patchy fog may provide brief visibility restrictions early this
morning primarily across far NW AR, otherwise VFR conditions
expected with very low coverage of afternoon storms.

&&

.PREV DISCUSSION... /Issued 940 PM CDT Tue Jul 27 2021/ 

DISCUSSION...
Diurnal convection has pretty much ended across our forecast area
this evening, and fair but warm conditions should prevail the
remainder of the night, as the air mass stabilizes and mid level 
heights rise. Earlier forecast update cleaned up today's heat 
headlines and thunderstorm chances that we continued into the early 
evening, otherwise forecast is on track with overnight temperatures 
likely falling to readings close to those of this morning with little
air mass change. Another hot day in store tomorrow with less chances
of rain as mid level ridge builds over the Southern Plains, and 
deeper moisture continues to be pushed southward.

PREV DISCUSSION... /Issued 626 PM CDT Tue Jul 27 2021/ 

AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
Isolated showers and storms across eastern OK will dissipate
over the next few hours. Outside of some localized fog across
parts of northwest AR, expect VFR conditions to prevail.

PREV DISCUSSION... /Issued 319 PM CDT Tue Jul 27 2021/ 

DISCUSSION...
Hot and humid conditions continued across much of Eastern Oklahoma
and Northwest Arkansas this afternoon with dewpoints in the 70s
and temps in the 90s common. These conditions were creating heat
index values in the 105 to 111 deg range over much of the CWA,
especially over locations not currently receiving rainfall. 
Thus...will allow for current heat headlines to continue. 

Isolated to scattered showers and thunderstorms had developed 
once again with the daytime heating. The bulk of this activity was
ongoing over Southeast Oklahoma while more isolated activity was 
observed over parts of Northeast Oklahoma and Northwest Arkansas. 
Moderate to steep low level lapse rates will aid in convection 
having the potential for gusty to strong winds reaching the 
surface. Very weak shear values should limit hail production. 
Instability weakens with the loss of daytime heating and 
thus...ongoing activity should dissipate by mid evening.

Dome of high pressure centered currently over the Central Plains
is progged to expand over the Southern Plains this week with a
return of southerly low level flow by Thursday. In response...hot
and humid conditions are forecast to continue through the week
with afternoon temperatures each afternoon at or slightly warmer
compared to the day before. Surface dewpoints are still expected
to be slightly less...though still remaining in the 70s...for the
rest of this week. This will create heat index values of 105 to
around 110 deg each afternoon and as such have expanded the heat 
advisory to include Wednesday afternoon. Depending on the 
dewpoints react Wednesday...a portion of this advisory could be 
upgraded to an excessive heat warning. Also...with the warming 
temps...the rest of Northwest Arkansas could get included in the 
heat headlines at some point this week.

Over the weekend...the ridge of high pressure is progged to become
more amplified from north to south across the Western CONUS as a
longwave trof axis drops southeast into the Eastern CONUS. This
should put the CWA on the far eastern fringe of the ridge and the
western periphery of the long wave trof. In response...Saturday
looks to be the warmest day of the forecast period ahead of a cold
front forecast to approach/move into the region from the 
northeast Sunday/Monday. High temps Saturday look to reach into
the upper 90s to around 102 deg across the CWA. Shower and
thunderstorm chances look to return as the cold front approaches
Sunday and continue into Monday. With this late weekend
system...some relief from the hot and humid conditions will be
possible as highs early next week could drop back into the 80s.
There continues to be uncertainty with how far the frontal
boundary can push through the region. If it hangs up north of the
CWA...then hot and humid conditions could continue. Will continue
to monitor as latest data come in.

&&

.PRELIMINARY POINT TEMPS/POPS...
TUL   97  77  99  78 /   0   0   0   0 
FSM   98  77 101  78 /  10   0   0   0 
MLC   97  75  99  76 /  10   0   0   0 
BVO   95  74  97  74 /   0   0   0   0 
FYV   95  72  96  73 /   0   0   0   0 
BYV   96  73  97  74 /   0   0   0   0 
MKO   96  75  97  76 /   0   0   0   0 
MIO   95  75  97  75 /   0   0   0   0 
F10   97  76  98  76 /   0   0   0   0 
HHW   96  76  97  77 /  10   0   0   0 

&&

.TSA WATCHES/WARNINGS/ADVISORIES...
OK...Heat Advisory from noon today to 8 PM CDT this evening for 
     OKZ049-053>076.

AR...Heat Advisory from noon today to 8 PM CDT this evening for 
     ARZ019-020-029.

&&

$$


AVIATION.....07