Excessive Heat in Oklahoma, August 19 to 20, 2019

Area Forecast Discussion
National Weather Service Tulsa OK
1236 PM CDT Mon Aug 19 2019

.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
Few to scattered mid and high clouds are forecast this afternoon
with some passing high clouds overnight tonight across the CWA. An
isolated shower/storm may be possible this afternoon over
Northwest Arkansas...though with isolated coverage forecast will
keep mention out of the TAFs for now. During the day Tuesday...few
to scattered mid and high clouds should again be possible. Winds
through the period are forecast to be fairly light varying from
east to southwest.

&&

.PREV DISCUSSION... /Issued 1055 AM CDT Mon Aug 19 2019/

..UPDATE...

DISCUSSION...
Upper level ridge of high pressure remained the dominate feature
across the Southern Plains at mid morning. At the surface...a
surface frontal boundary was positioned west to east across Kansas
with hot and humid conditions quickly developing south of the
boundary over Eastern Oklahoma and Northwest Arkansas.

Through this afternoon...the ridge of high pressure will remain in
place with the surface boundary staying north of the CWA.
Thus...hot and humid conditions will continue across the CWA with
highs in the mid to upper 90s and southerly winds of 5 to 15 mph
common. A few locations across Eastern Oklahoma could make a run
at 100 degrees. Dewpoints are expected to remain in the 70s
through the afternoon which will create heat index values in the
105 to near 115 degrees for the CWA. In response...current heat
headlines look to be in good shape at this time.

Also this afternoon...a few isolated diurnal showers and
thunderstorms still look to be possible mainly across the higher
terrain locations of Northwest Arkansas. Locally strong winds look
to be the main threat as deep layer shear values are expected to
be marginal within any convection. The greater instability is
forecast to reside just north of the CWA near the surface
boundary and organized severe weather is not currently
anticipated.

For the morning update...have tweaked temps/dewpoints slightly
higher and also added latest trends/obs to hourly grids. The rest
of the forecast seem to be handling well at this time.

&&

.PRELIMINARY POINT TEMPS/POPS...
TUL   78  98  77  94 /   0   0   0  20
FSM   77  98  77  96 /   0   0   0  20
MLC   77  98  76  96 /   0   0   0  10
BVO   74  96  74  92 /   0   0   0  30
FYV   71  93  72  91 /   0   0   0  30
BYV   72  95  73  92 /   0   0   0  30
MKO   75  97  75  94 /   0   0   0  20
MIO   75  94  74  92 /   0   0   0  30
F10   76  99  75  94 /   0   0   0  20
HHW   76  97  76  98 /   0   0   0  10

&&

.TSA WATCHES/WARNINGS/ADVISORIES...
OK...Heat Advisory until 9 PM CDT this evening for OKZ049-053-058-063-
     068-069.

     Heat Advisory from 1 PM to 9 PM CDT Tuesday for OKZ049-053>076.

     Excessive Heat Warning until 9 PM CDT this evening for
     OKZ054>057-059>062-064>067-070>076.

AR...Heat Advisory until 9 PM CDT this evening for ARZ001-010.

     Heat Advisory from 1 PM to 9 PM CDT Tuesday for ARZ001-010-019-
     020-029.

     Excessive Heat Warning until 9 PM CDT this evening for ARZ019-
     020-029.

&&

AVIATION.....20

Hazardous Weather Outlook
National Weather Service Tulsa OK
501 AM CDT Mon Aug 19 2019

ARZ001-002-010-011-019-020-029-OKZ049-053>076-201015-
Adair OK-Benton AR-Carroll AR-Cherokee OK-Choctaw OK-Craig OK-
Crawford AR-Creek OK-Delaware OK-Franklin AR-Haskell OK-Latimer OK-
Le Flore OK-Madison AR-Mayes OK-McIntosh OK-Muskogee OK-Nowata OK-
Okfuskee OK-Okmulgee OK-Osage OK-Ottawa OK-Pawnee OK-Pittsburg OK-
Pushmataha OK-Rogers OK-Sebastian AR-Sequoyah OK-Tulsa OK-Wagoner OK-
Washington OK-Washington AR-
501 AM CDT Mon Aug 19 2019

...VERY DANGEROUS HEAT EXPECTED TODAY...
...DANGEROUS HEAT CONTINUES INTO TUESDAY...

This Outlook is for Northwest and West Central Arkansas as well as
much of Eastern Oklahoma.

.DAY ONE...Today and Tonight.

THUNDERSTORMS WITH DANGEROUS LIGHTNING.
	RISK...Limited.
	AREA...Terrain areas of Western Arkansas.
	ONSET...Afternoon.

DANGEROUS HEAT.
	RISK...Significant.
	AREA...Eastern Oklahoma and Western Arkansas.
	ONSET...Midday.

	AREA AT GREATEST RISK...Northeast and East-Central Oklahoma
							West-Central Arkansas.

DISCUSSION...

Very dangerous heat is expected today as high dewpoints combine
with hot temperatures beneath a building ridge of high pressure
aloft. Afternoon heat indices will top out between 105 and 115
degrees across much of the region, with the worst conditions
forecast over northeast and east-central Oklahoma as well as
west-central Arkansas.

An isolated afternoon terrain induced thunderstorm is possible
over western Arkansas. A brief heavy downpour and dangerous
lightning will accompany any storm that develops.

SPOTTER AND EMERGENCY MANAGEMENT ACTION STATEMENT...
Spotter Activation Not Expected.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.
TUESDAY...Dangerous Heat Potential.
WEDNESDAY...Thunderstorm Potential...Dangerous Heat Potential.
THURSDAY thru SUNDAY...Thunderstorm Potential.

EXTENDED DISCUSSION...

Another day of dangerous heat is expected Tuesday as a ridge of
high pressure aloft resides directly over the region. This heat
may also continue into Wednesday, south of any influences from
clouds and storms that will be arriving from Kansas.

A cold front will bring relief from the heat and greater chances
for thunderstorms for the latter part of the week. Locally heavy
rainfall and a limited severe wind threat will accompany these
storms.

EMERGENCY MANAGEMENT PLANNING STATEMENT...

With the intensity of the heat increasing, first responders
should expect an increase in heat-related incidents over the next
couple of days.

weather.gov/tulsa contains additional information.

Lacy