Alert archive / Oklahoma / Flash Flood Warnings in 2017

Flash Flood Warning 44, NWS Tulsa, OK

August 13, 2017Sequoyah County, Oklahoma

NWS Tulsa, OK issued this flash flood warning at Aug 13, 2017, 4:23 AM CDT for Sequoyah County, Oklahoma. It was in force for 4 hr. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 13, 2017, 4:23 AM CDT (09:23 UTC)
Expired: Aug 13, 2017, 8:15 AM CDT
In force: 4 hr
Issued by: NWS Tulsa, OK
Area: Storm-based polygon
Flood severity: None

County Sequoyah County, OK

The radar

The Western Arkansas radar (KSRX), 32 km from the middle of the area, began a volume at 09:22 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
Aug 13, 4:30 AM CDT	FLASH FLOOD	Gans, OK	SEQUOYAH COUNTY EM REPORTS SOME ROADS IN THE COUNTY ARE IMPASSABLE, IN THE GANS AREA AND OTHER SPOTS
Aug 13, 4:53 AM CDT	FLASH FLOOD	6 E Sallisaw, OK	ROADS IMPASSABLE EAST OF TOWN. WATER RESCUE ONGOING ON E 1070 RD.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Springfield, MO (KSGF), launched 00:00Z, 9.4 hours before the alert went out and 190 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1182 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 19 m²/s²
0-3 km storm-relative helicity: 47 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

068 
WGUS54 KTSA 130923
FFWTSA
OKC135-131315-
/O.NEW.KTSA.FF.W.0044.170813T0923Z-170813T1315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tulsa OK
423 AM CDT SUN AUG 13 2017

The National Weather Service in Tulsa has issued a

* Flash Flood Warning for...
  Central Sequoyah County in east central Oklahoma...

* Until 815 AM CDT

* At 421 AM CDT, Doppler radar indicated a nearly stationary 
  thunderstorm producing very heavy rain across central Sequoyah 
  county. Radar estimates that nearly 4 inches of rain has fallen in 
  the Little Sallisaw Creek basin. Flash flooding is expected to 
  begin shortly.

* Some locations that may experience flooding include...
  Sallisaw...                       Muldrow...
  Gans...                           Marble City...
  Brushy Lake State Park...         Brushy...
  Mc Key...                         Cottonwood...

Additional heavy rain is possible in the warned area as more storms 
approach from the west.

This includes Interstate 40 in Oklahoma between mile markers 302 and
322.
 
LAT...LON 3533 9457 3533 9460 3529 9463 3529 9466
      3531 9468 3532 9468 3536 9474 3536 9477
      3532 9480 3533 9482 3536 9483 3537 9484
      3535 9489 3558 9489 3558 9454 3530 9454

$$

Lacy

1 follow-up statement

297 
WGUS74 KTSA 131017
FFSTSA

Flash Flood Statement
National Weather Service Tulsa OK
517 AM CDT SUN AUG 13 2017

OKC135-131315-
/O.CON.KTSA.FF.W.0044.000000T0000Z-170813T1315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sequoyah OK-
517 AM CDT SUN AUG 13 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 AM CDT FOR
CENTRAL SEQUOYAH COUNTY...

At 513 AM CDT, trained weather spotters reported flash flooding due 
to a nearly stationary thunderstorm over central Sequoyah county. 
Radar estimates that between 4 and 6 inches of rain has fallen east 
of Sallisaw. Roads are impassable in the Gans area and east of 
Sallisaw, where water rescues are ongoing.

Some locations that may experience flooding include...
Sallisaw...                       Muldrow...
Gans...                           Marble City...
Brushy Lake State Park...         Brushy...
Mc Key...                         Cottonwood...

Moderate to heavy rain continues across the warned area, but should 
begin to taper off within an hour or so.

This includes Interstate 40 in Oklahoma between mile markers 302 and
322.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 3533 9457 3533 9460 3529 9463 3529 9466
      3531 9468 3532 9468 3536 9474 3536 9477
      3532 9480 3533 9482 3536 9483 3537 9484
      3535 9489 3558 9489 3558 9454 3530 9454

$$

Lacy

The office that day

Everything else NWS Tulsa, OK issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 13, 2:20 AM CDT	Areal Flood Advisory	TSA	McIntosh	3 hr
Aug 13, 3:25 AM CDT	Areal Flood Advisory	TSA	Haskell, LeFlore, Muskogee, Sequoyah	3 hr
Aug 13, 6:32 AM CDT	Areal Flood Advisory	TSA	Haskell, Latimer, LeFlore	3 hr
Aug 13, 8:13 AM CDT	Areal Flood Warning	TSA	Sequoyah	3 hr
Aug 13, 11:12 AM CDT	Areal Flood Warning	TSA	Sequoyah	27 hr
Aug 13, 11:14 AM CDT	River Flood Advisory	TSA	Sequoyah	36 hr

Nearby

Flash Flood Warnings in Oklahoma, 2017 Every flash flood warning in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.