Special Weather Statement, NWS Tulsa, OK

Area Forecast Discussion
National Weather Service Tulsa OK
1249 AM CDT Sat Jul 17 2021

.DISCUSSION...
Spotty thunderstorms are developing across parts of E OK and NW AR
with storms near our NW AR terminals at the time of writing. These
storms are expected to be largely stationary tonight so if they
become established they will likely go for awhile. If the right
storm pops over a terminal, expect a prolonged period of MVFR to
IFR conditions with heavy rainfall potentially leading to LIFR
conditions at times. With this said, confidence was too low to
really lower conditions at any one airport but trends will be
monitored over the next few hours with amendments made if
necessary.

After a break this morning, additional showers and storms are
expected to develop with day time heating across much of E OK and
NW AR. There is still some uncertainty into the coverage for this
afternoon as guidance continues to vary. With that said,
confidence is medium to high in showers/storms affecting
terminals across E OK and NW AR but medium in terms of timing and
duration. MVFR to brief IFR conditions can be expected with any
activity.

Snider

&&

.PREV DISCUSSION... /Issued 913 PM CDT Fri Jul 16 2021/

..UPDATE...

DISCUSSION...
Latest radar imagery shows isolated convection continuing along
the KS/OK border to the west of Osage County and within a zone of
deeper convergence with signs of new development further east.
This activity is forecast by short term models to expand eastward
across northeast OK overnight and potentially become anchored in
the area that saw heavy rainfall last night. Current forecast has
the highest POPs across northern most counties but if current
trends continue these may need to be increased especially in the
09-15Z time frame. Flooding will also be a concern if storms with
higher rainfall rates do materialize and begin to train over this
area. Other region of concern is far southeast OK where there has
been a signal for development in a similar warm advection pattern
though this area is also beneath more diffluent flow aloft which
would favor backbuilding cells. Overall there is lower confidence
in this as focus may be initially further south into north TX.

Remainder of forecast looks in good shape and aside from possible
increase in POPs and clouds across northeast OK/northwest AR no
major changes are anticipated.

PREV DISCUSSION... /Issued 616 PM CDT Fri Jul 16 2021/

AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
VFR conditions prevail this evening across eastern Oklahoma
and western Arkansas. Shower and thunderstorm coverage will
likely increase later this evening and overnight across
northeast Oklahoma and northwest Arkansas. With uncertainty
on how the convection will evolve, have only included VCTS
at the northeast Oklahoma and northwest Arkansas TAFs.
VFR conditions will likely continue through tonight with MVFR
to IFR conditions possible in and near thunderstorm areas.

PREV DISCUSSION... /Issued 231 PM CDT Fri Jul 16 2021/

DISCUSSION...
Main area of convection continues to slowly push to the south and
east this afternoon, leaving an outflow boundary from far
southeast into north central OK. Mid level trough will also
continue to slide southeast tonight and while overall forcing will
not be as strong tonight, persistent warm advection and moisture
transport will continue to interact with the above mentioned
boundary. At least scattered showers and thunderstorms are likely
to redevelop later this afternoon and evening as a result, albeit
less organized than what we saw early the morning. At this time
no additional, flood watches are planned, though a corridor of
higher precip chances may become defined later this evening and
should it coincide with areas that already saw heavy rain, a
short-fused watch could be needed.

Effective boundary with a humid airmass and at least subtle
forcing in NW flow aloft will persist the next couple of days,
resulting in continues showers and thunderstorm chances. Given
precipitable water in the 2 inch range, efficient rain production
remains likely and any areas that receive additional rounds of
rainfall will be prone to flooding. The overall trend though
should be for the highest probability to shift a bit south by
Saturday into Sunday.

Monday continues to show higher precip chances as western US
ridge amplifies and mid level low in northerly flow drops south
and west into the area. By mid to late next week, it appears ridge
will strengthen over the southern plains resulting in more
typical summer weather with hot and humid conditions and reduced
precip chances.

&&

.PRELIMINARY POINT TEMPS/POPS...
TUL   91  72  90  71 /  30  30  30  40
FSM   90  72  90  72 /  70  40  50  40
MLC   91  72  90  69 /  50  40  40  40
BVO   89  70  89  69 /  30  20  30  30
FYV   87  67  87  66 /  40  40  40  30
BYV   87  69  87  67 /  30  30  40  20
MKO   89  70  87  70 /  50  30  30  40
MIO   88  70  88  68 /  50  20  30  20
F10   91  71  89  69 /  40  40  30  40
HHW   90  73  91  72 /  40  40  40  40

&&

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

LONG TERM....99

Hazardous Weather Outlook
National Weather Service Tulsa OK
526 PM CDT Fri Jul 16 2021

ARZ001-002-010-011-019-020-029-OKZ049-053>076-171045-
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-
526 PM CDT Fri Jul 16 2021

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

.DAY ONE...Today and Tonight.

SEVERE THUNDERSTORM.
	RISK...Limited.
    AREA...Eastern Oklahoma and Northwest Arkansas.
    ONSET...Ongoing.

FLASH FLOOD.
	RISK...Limited.
	AREA...Eastern Oklahoma and Northwest Arkansas.
    ONSET...Late this evening.

HEAVY RAIN.
	RISK...Limited.
	AREA...Eastern Oklahoma and Northwest Arkansas.
    ONSET...Late this evening.

DISCUSSION...
Isolated showers and thunderstorms will develop this evening
across portions of eastern Oklahoma or may move into the area
from southern Kansas. High instability and slightly stronger winds
aloft may allow one or two storms to become strong to marginally
severe. The main threat will be gusty winds with a lesser concern
for large hail. Locally heavy rainfall will also be possible
across a broader area of eastern Oklahoma and northwest Arkansas
late this evening and overnight as additional storms develop or
existing activity grows upscale into clusters. Slow movement of
the activity combined with efficient rainfall rates may lead to
localized flash flooding.

SPOTTER AND EMERGENCY MANAGEMENT ACTION STATEMENT...
Local Spotter Activation May Be Needed.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.
SATURDAY...Thunderstorm Potential...Heavy Rain Potential.
SUNDAY THROUGH THURSDAY...Thunderstorm Potential.

EXTENDED DISCUSSION...
A nearly stationary frontal boundary and existing outflow
boundaries from earlier storms will continue to provide a focus
for shower and thunderstorm activity through the weekend across
much of eastern Oklahoma and western Arkansas. A developing upper
level disturbance over the Missouri Valley late in the weekend
into early next week will result in a general increase in
rainfall coverage. The persistent threat of showers and
thunderstorms along with abundant moisture will continue the
threat for locally heavy rainfall. Organized severe weather is not
expected.

weather.gov/tulsa contains additional information.

Special Weather Statement
National Weather Service Tulsa OK
944 PM CDT Fri Jul 16 2021

OKZ054-170330-
Osage OK-
944 PM CDT Fri Jul 16 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTH CENTRAL OSAGE COUNTY UNTIL
1030 PM CDT...

At 944 PM CDT, a strong thunderstorm was located 3 miles northeast of
Grainola, moving southeast at 10 mph.

Penny size hail and winds in excess of 40 mph will be possible with
this storm.

Locations in or near the path include...
Grainola...                       Foraker...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3700 9646 3689 9634 3675 9663 3699 9675
      3700 9673
TIME...MOT...LOC 0244Z 328DEG 11KT 3698 9661

Special Weather Statement
National Weather Service Tulsa OK
125 AM CDT Sat Jul 17 2021

OKZ054-170700-
Osage OK-
125 AM CDT Sat Jul 17 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN OSAGE COUNTY UNTIL
200 AM CDT...

At 124 AM CDT, a strong thunderstorm was located 5 miles west of
Bigheart, moving northeast at 15 mph.

Wind gusts up to 50 mph will be possible with this storm.

Locations in or near the path include...
Pawhuska...                       Elgin...
Bigheart...                       Hulah...
Sunset Lake...                    Pearsonia...
Wah Sha She State Park...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3700 9602 3698 9600 3690 9600 3667 9633
      3688 9652 3700 9636
TIME...MOT...LOC 0624Z 231DEG 14KT 3688 9632

Snider

Special Weather Statement
National Weather Service Tulsa OK
149 AM CDT Sat Jul 17 2021

OKZ062-063-170715-
Delaware OK-Mayes OK-
149 AM CDT Sat Jul 17 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN DELAWARE AND
NORTHEASTERN MAYES COUNTIES UNTIL 215 AM CDT...

At 148 AM CDT, a strong thunderstorm was located 4 miles southeast of
Spavinaw, moving west at 10 mph.

Wind gusts up to 50 mph will be possible with this storm.

Locations in or near the path include...
Spavinaw...                       Hoot Owl...
Spavinaw State Park...            Strang...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3642 9491 3626 9489 3625 9514 3641 9515
TIME...MOT...LOC 0648Z 091DEG 7KT 3634 9500

Snider

Special Weather Statement
National Weather Service Tulsa OK
222 AM CDT Sat Jul 17 2021

OKZ062-170745-
Mayes OK-
222 AM CDT Sat Jul 17 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN MAYES COUNTY UNTIL
245 AM CDT...

At 222 AM CDT, a strong thunderstorm was located over Hoot Owl,
moving west at 5 mph.

Wind gusts of 50 to 55 mph will be possible with this storm.

Locations in or near the path include...
Salina...                         Spavinaw...
Hoot Owl...                       Spavinaw State Park...
Strang...                         Snowdale State Park...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3643 9502 3634 9500 3627 9501 3627 9522
      3641 9522
TIME...MOT...LOC 0722Z 082DEG 6KT 3634 9512

Snider