Flash Flood Warning 11, NWS Tulsa, OK

Area Forecast Discussion
National Weather Service Tulsa OK
341 PM CDT Fri Sep 21 2018

.DISCUSSION...

The heavy rain/flood threat over the next 24 hours will be the
main forecast concern today.

A squeeze play of sorts is occurring over our area today. A cold
front is advancing south into the region, while to the south a
pseudo-warm front lies from the Red River valley northeast toward
Fort Smith. In between these boundaries, there is diffluent flow
aloft within a deformation zone that extends northeast of an upper
low at the basal portion of a southern stream trough. The
environment is characterized to be tropical, with PW values near
or exceeding 2 inches. This tropical plume of moisture also
contains the remnants of TD 19 from the eastern Pacific.

Where the heavier rains have been able to focus along slow moving
or nearly stationary bands, some very impressive rainfall totals
have been observed. The Fittstown Mesonet station in south central
Oklahoma has picked up nearly a foot of rain today, while a fairly
steady north-south band of heavy rain showers dropped about 5 and
a quarter inches on Talihina. Another band of heavy rain set up
across the southern portion of the Tulsa metro area down near
Bixby where some flooding has been reported.

The hi-res guidance suggests that as the cold front, which is
ushering in much drier air, continues south, the axis of heavier
rain potential will also shift south by tonight, setting up closer
to the I-40 corridor from east central and southeast OK into west
central AR. As has been observed thus far, there will be pockets
of very heavy rainfall where bands set up within the broader zone
of ascent. Very localized amounts from 6 to 10 inches are
possible. The going flash flood watch will be maintained as is,
but some shaving of the watch from north to south will likely be
needed as the cold front pushes south. The heavy rain threat will
continue to shift south and east thru the day on Saturday, with
the threat ending by Sunday morning.

A more amplified flow pattern is forecast next week, which is
expected to bring at least a pair of cold fronts thru the region.
This is a sign that the transition of seasons has begun. The first
cold front will slide thru Tuesday night, with some chance for
showers and storms with it. Another front is expected toward the
end of the week, though this front looks rather weak.

Lacy

&&

.PRELIMINARY POINT TEMPS/POPS...
TUL   60  73  60  79 /  80  30  10  20
FSM   66  68  63  76 / 100  90  40  50
MLC   64  68  62  76 / 100  90  50  40
BVO   57  76  56  79 /  40  10  10  10
FYV   60  67  58  74 / 100  80  20  40
BYV   59  66  58  74 /  90  80  20  40
MKO   62  69  61  77 / 100  80  30  30
MIO   59  73  57  78 /  50  20  10  20
F10   62  70  61  76 / 100  70  30  30
HHW   70  72  65  77 /  90  90  60  60

&&

.TSA WATCHES/WARNINGS/ADVISORIES...
OK...Flash Flood Watch through Sunday morning for OKZ049-053-060>076.

AR...Flash Flood Watch through Sunday morning for ARZ001-002-010-011-
     019-020-029.

&&

LONG TERM....30

Hazardous Weather Outlook
National Weather Service Tulsa OK
455 PM CDT Fri Sep 21 2018

ARZ001-002-010-011-019-020-029-OKZ049-053>076-221030-
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-
455 PM CDT Fri Sep 21 2018

...HEAVY RAINFALL LIKELY THROUGH SATURDAY NIGHT...

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

.DAY ONE...Today and Tonight.

FLASH FLOOD.
	RISK...Elevated.
	AREA...Mainly Southeast of Interstate 44.
	ONSET...Ongoing.

HEAVY RAIN.
	RISK...Significant.
	AREA...Mainly Southeast of Interstate 44.
	ONSET...Ongoing.

	AREA AT GREATEST RISK...Along and South of Interstate 40.

THUNDERSTORMS WITH DANGEROUS LIGHTNING.
	RISK...Limited.
	AREA...Western Arkansas and Southeast Oklahoma.
	ONSET... .

SIGNIFICANT WINDS.
	RISK...Limited.
	AREA...Northeast Oklahoma.
	ONSET...Ongoing.

DISCUSSION...
Widespread heavy rainfall is expected across the region through
tonight with the greater potential for excessive rainfall becoming
more focused along and south of Interstate 40 through the
evening. This heavy rainfall will likely result in some flash
flooding and a Flash Flood Watch remains in effect for much of
Eastern Oklahoma and all of Northwest Arkansas.

Widespread rain showers along with isolated thunderstorms will
continue across Eastern Oklahoma and Northwest Arkansas as a cold
front makes its way into the region and interacts with tropical
moisture in place. Rain will decrease through the evening across
northeast Oklahoma as the cold front ushers in drier air.

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

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.
SATURDAY...Thunderstorm Potential...Heavy Rain Potential.
SUNDAY...No Hazards.
MONDAY through THURSDAY...Thunderstorm Potential.

EXTENDED DISCUSSION...
Widespread showers and thunderstorms will continue across much of
eastern Oklahoma and northwestern Arkansas through Saturday night
as the cold front slowly pushes south. Heavy rainfall will
continue through Saturday night and into Sunday morning. An axis
of three to six inch storm-total rainfall amounts is expected
across southeastern Oklahoma and west central Arkansas through
Sunday morning, with one to three inches possible across
northeastern Oklahoma and northwest Arkansas. Locally heavier
amounts are likely across southeastern Oklahoma. Flash flooding
will be possible into Sunday morning, and minor to moderate
mainstem river flooding is possible depending on where the
heaviest rainfall occurs.

An active weather pattern will continue across eastern Oklahoma and
northwest Arkansas into late next week. Moist and unstable air will
remain over the area, and a couple cold fronts are expected to move
into the area on Tuesday and again on Thursday. Thunderstorms will be
possible each day from Sunday through Thursday but organized severe
weather is not expected at this time during this period.

weather.gov/tulsa contains additional information.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
253 PM CDT FRI SEP 21 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0252 PM     FLASH FLOOD      BIXBY                   35.94N 95.88W
09/21/2018                   TULSA              OK   PUBLIC

            131ST NEAR MEMORIAL IS NEARLY IMPASSABLE DUE TO FLOODING.

0252 PM     FLASH FLOOD      TULSA                   36.13N 95.92W
09/21/2018                   TULSA              OK   BROADCAST MEDIA

            YALE AVENUE IS CLOSED BETWEEN 51ST AND 61ST DUE TO
            FLOODING.

&&

KAH