Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2020
Severe Thunderstorm Warning 255, NWS Tulsa, OK
NWS Tulsa, OK issued this severe thunderstorm warning at Jul 11, 2020, 6:57 PM CDT for Delaware County, Ottawa County, Oklahoma. It was in force for 48 min. 5 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
- Jul 11, 2020, 6:57 PM CDT (23:57 UTC)
- Expired
- Jul 11, 2020, 7:45 PM CDT
- In force
- 48 min
- Issued by
- NWS Tulsa, OK
- Area
- Storm-based polygon
- Hail
- 1.75 in
- Wind
- 70.0 mph
Counties Delaware County, OK, Ottawa County, OK
The radar
The Tulsa radar (KINX), 100 km from the middle of the area, began a volume at 23:58 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 |
|---|---|---|---|
| Jul 11, 6:58 PM CDT | HAIL 1.25 | 3 Sw Miami, OK | |
| Jul 11, 7:13 PM CDT | HAIL 1 | 1 E Narcissa, OK | DAMAGE TO SMALL TREE LIMBS ALSO OCCURRING. |
| Jul 11, 7:15 PM CDT | HAIL 1 | 1 N Fairland, OK | |
| Jul 11, 7:26 PM CDT | HAIL 1.75 | 4 S Fairland, OK | STORM TRACKER REPORTED GOLFBALL HAIL NEAR THE INTERSECTION OF HWY 59 AND 125 SOUTH OF FAIRLAND |
| Jul 11, 7:32 PM CDT | HAIL 1.75 | Grove, OK |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
Did it verify
Verified. The Iowa Environmental Mesonet's Cow matched 5 storm reports to this severe thunderstorm warning; the first came 1 minutes after it went out.
Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jul 11, 3:36 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 11, 6:08 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Springfield, MO (KSGF), launched 12:00Z, 12.0 hours before the alert went out and 88 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.
- Mixed-layer CAPE
- 1333 J/kg
- Mixed-layer CIN
- -95 J/kg
- Mixed-layer LCL
- 1092 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 41 m²/s²
- 0-3 km storm-relative helicity
- 80 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
The text
As transmitted.
224
WUUS54 KTSA 112357
SVRTSA
OKC041-115-120045-
/O.NEW.KTSA.SV.W.0255.200711T2357Z-200712T0045Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Tulsa OK
657 PM CDT Sat Jul 11 2020
The National Weather Service in Tulsa has issued a
* Severe Thunderstorm Warning for...
Northern Delaware County in northeastern Oklahoma...
Ottawa County in northeastern Oklahoma...
* Until 745 PM CDT.
* At 656 PM CDT, a severe thunderstorm was located 3 miles north of
Narcissa, moving southeast at 35 mph.
HAZARD...Golf ball size hail and 70 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...People and animals outdoors will be injured. Expect hail
damage to roofs, siding, windows, and vehicles. Expect
considerable tree damage. Wind damage is also likely to
mobile homes, roofs, and outbuildings.
* Locations in or near the path include...
Miami... Grove...
Commerce... Fairland...
Afton... Quapaw...
Bernice... Wyandotte...
Honey Creek State Park... Bernice State Park...
Narcissa... Ottawa...
Peoria... Cardin...
Zena... Twin Bridges State Park...
This includes Interstate 44 between mile markers 296 and 320.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Prepare immediately for large hail and damaging winds. People outside
should move immediately to shelter inside a strong building. Stay
away from windows.
To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in Tulsa.
If on or near Grand Lake, get away from the water and move indoors
or inside a vehicle. Remember, lightning can strike out to 15 miles
from the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not
be caught on the water in a thunderstorm.
&&
LAT...LON 3693 9462 3657 9462 3647 9491 3688 9500
3697 9496 3698 9476
TIME...MOT...LOC 2356Z 325DEG 29KT 3685 9493
HAIL...1.75IN
WIND...70MPH
$$3 follow-up statements
404
WWUS54 KTSA 120018
SVSTSA
Severe Weather Statement
National Weather Service Tulsa OK
718 PM CDT Sat Jul 11 2020
OKC041-115-120045-
/O.CON.KTSA.SV.W.0255.000000T0000Z-200712T0045Z/
Delaware OK-Ottawa OK-
718 PM CDT Sat Jul 11 2020
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM CDT
FOR NORTHERN DELAWARE AND SOUTHERN OTTAWA COUNTIES...
At 717 PM CDT, a severe thunderstorm was located 3 miles southeast of
Fairland, moving southeast at 35 mph.
HAZARD...Golf ball size hail and 70 mph wind gusts.
SOURCE...Radar indicated. Quarter size hail was reported near
Narcissa and near Fairland.
IMPACT...People and animals outdoors will be injured. Expect hail
damage to roofs, siding, windows, and vehicles. Expect
considerable tree damage. Wind damage is also likely to
mobile homes, roofs, and outbuildings.
Locations in or near the path include...
Miami... Grove...
Fairland... Afton...
Bernice... Wyandotte...
Honey Creek State Park... Narcissa...
Bernice State Park... Ottawa...
Zena... Twin Bridges State Park...
This includes Interstate 44 between mile markers 296 and 307.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and away from
windows.
To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Tulsa.
If on or near Grand Lake, get away from the water and move indoors
or inside a vehicle. remember, lightning can strike out to 15 miles
from the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not
be caught on the water in a thunderstorm.
&&
LAT...LON 3681 9463 3657 9462 3647 9491 3681 9499
3684 9494 3686 9480
TIME...MOT...LOC 0017Z 325DEG 29KT 3671 9481
HAIL...1.75IN
WIND...70MPH
$$811
WWUS54 KTSA 120030
SVSTSA
Severe Weather Statement
National Weather Service Tulsa OK
730 PM CDT Sat Jul 11 2020
OKC041-115-120045-
/O.CON.KTSA.SV.W.0255.000000T0000Z-200712T0045Z/
Delaware OK-Ottawa OK-
730 PM CDT Sat Jul 11 2020
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM CDT
FOR NORTHERN DELAWARE AND SOUTHERN OTTAWA COUNTIES...
At 729 PM CDT, a severe thunderstorm was located 4 miles northwest of
Grove, moving southeast at 30 mph.
HAZARD...Golf ball size hail and 70 mph wind gusts.
SOURCE...Radar indicated. Golfball size hail was reported 4 miles
south of Fairland.
IMPACT...People and animals outdoors will be injured. Expect hail
damage to roofs, siding, windows, and vehicles. Expect
considerable tree damage. Wind damage is also likely to
mobile homes, roofs, and outbuildings.
Locations in or near the path include...
Grove... Fairland...
Afton... Bernice...
Honey Creek State Park... Bernice State Park...
Zena...
This includes Interstate 44 between mile markers 296 and 300.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and away from
windows.
To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Tulsa.
If on or near Grand Lake, get away from the water and move indoors
or inside a vehicle. remember, lightning can strike out to 15 miles
from the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not
be caught on the water in a thunderstorm.
&&
LAT...LON 3678 9467 3657 9462 3647 9491 3674 9497
3676 9491 3678 9479
TIME...MOT...LOC 0029Z 328DEG 24KT 3665 9481
HAIL...1.75IN
WIND...70MPH
$$331
WWUS54 KTSA 120039
SVSTSA
Severe Weather Statement
National Weather Service Tulsa OK
739 PM CDT Sat Jul 11 2020
OKC041-115-120045-
/O.CON.KTSA.SV.W.0255.000000T0000Z-200712T0045Z/
Delaware OK-Ottawa OK-
739 PM CDT Sat Jul 11 2020
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM CDT
FOR NORTHEASTERN DELAWARE AND SOUTHEASTERN OTTAWA COUNTIES...
At 739 PM CDT, a severe thunderstorm was located over Grove, moving
southeast at 35 mph.
HAZARD...Golf ball size hail and 70 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...People and animals outdoors will be injured. Expect hail
damage to roofs, siding, windows, and vehicles. Expect
considerable tree damage. Wind damage is also likely to
mobile homes, roofs, and outbuildings.
Locations in or near the path include...
Grove... Honey Creek State Park...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and away from
windows.
To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Tulsa.
If on or near Grand Lake, get away from the water and move indoors
or inside a vehicle. remember, lightning can strike out to 15 miles
from the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not
be caught on the water in a thunderstorm.
&&
LAT...LON 3657 9462 3653 9482 3669 9486 3672 9477
3674 9466
TIME...MOT...LOC 0039Z 325DEG 29KT 3658 9475
HAIL...1.75IN
WIND...70MPH
$$What forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Tulsa, OK wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 11, 2:24 PM CDT, 4 hours 33 minutes earlier.
Area forecast discussion, Jul 11, 2:24 PM CDT, 4 hours 33 minutes before
Area Forecast Discussion
National Weather Service Tulsa OK
224 PM CDT Sat Jul 11 2020
...SEVERE WEATHER EXPECTED THIS EVENING ACROSS NE OK/NW AR...
.DISCUSSION...
Dangerously hot conditions this afternoon with heat indices
currently in the 110-116 degree range. Update was sent earlier to
expand excessive heat warning, including adding far northwest
Arkansas to the heat advisory.
Next concern will be the potential for significant severe weather
this evening into the overnight hours. Storms are currently
developing this afternoon across northeast Kansas along southward
moving cold front. Thunderstorm activity will continue pushing
south, moving into northeast Oklahoma by early to mid evening
with severe weather expected.
Atmosphere will likely remain very unstable with deep layer shear
increasing to around 50 knots. This environment will initially
support semi-discrete storms, with supercell characteristics,
producing large hail. Thunderstorms will likely quickly congeal
into one or more clusters with the potential for more widespread
damaging winds in the stronger bow segments across northeast
Oklahoma and northwest Arkansas. Greatest severe potential will be
along and north of I-40, however the remainder of the area will
also have at lest some some severe threat. Locally heavy rainfall/
flash flooding will also be possible as PWAT values remain in the
1.7-2.0 inch range. Storms should remain progressive enough however
to keep the flood threat fairly localized. Severe threat will
likely begin to diminish late tonight as storms slowly weaken/push
south of the area.
Actual cold front will be somewhat slow to move through the area
during the day Sunday. Expect hot/humid conditions to redevelop
along and south of I-40 ahead of front during the afternoon. A
few isolated strong to severe thunderstorms may also be possible
across southeast Oklahoma Sunday afternoon with FROPA.
Hot and humid conditions will likely return for much of next week
as large upper ridge shifts east into the southern Plains. Given
the recent rainfall and more expected tonight, increased NBM dew-
points through much of the extended periods with heat indices
back above 105 degrees by Tuesday through the remainder of the
work week.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 73 93 70 93 / 70 10 10 0
FSM 74 96 70 94 / 50 20 10 10
MLC 74 96 72 93 / 40 20 10 0
BVO 71 90 68 91 / 80 0 10 0
FYV 70 90 66 90 / 70 10 0 10
BYV 70 90 65 92 / 80 10 0 10
MKO 73 92 70 92 / 50 10 10 0
MIO 70 90 67 92 / 80 10 0 0
F10 73 93 70 93 / 40 10 10 0
HHW 75 98 76 95 / 30 20 10 0
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...Heat Advisory until 9 PM CDT this evening for Okays-063-068-069.
Excessive Heat Warning until 9 PM CDT this evening for OKZ049-
053>057-059>062-064>067-070>076.
AR...Heat Advisory until 9 PM CDT this evening for ARZ001-002-010-011.
Excessive Heat Warning until 9 PM CDT this evening for ARZ019-
020-029.
&&
LONG TERM....12Hazardous weather outlook, Jul 11, 4:44 PM CDT, 2 hours 13 minutes before
Hazardous Weather Outlook National Weather Service Tulsa OK 444 PM CDT Sat Jul 11 2020 ARZ001-002-010-011-019-020-029-OKZ049-053>076-121030- 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- 444 PM CDT Sat Jul 11 2020 ...SEVERE WEATHER LIKELY THIS EVENING... This Outlook is for Northwest and West Central Arkansas as well as much of Eastern Oklahoma. .DAY ONE...This Afternoon and Tonight. TORNADO. RISK...Limited. AREA...Mainly north of Highway 412. ONSET...After 7 pm. SEVERE THUNDERSTORM. RISK...Critical. AREA...Eastern Oklahoma and Northwest Arkansas. ONSET...After 7 pm. AREA AT GREATEST RISK...North of I-40. HEAVY RAIN. RISK...Limited. AREA...Northeast Oklahoma and Northwest Arkansas. ONSET...After 7 pm. DANGEROUS HEAT. RISK...Significant. AREA...Eastern Oklahoma and Northwest Arkansas. ONSET...Ongoing. AREA AT GREATEST RISK...Eastern Oklahoma and West Central Arkansas. DISCUSSION... Severe weather is expected to develop into northeastern Oklahoma and northwest Arkansas this evening through early tonight. The primary threat will be damaging wind gusts up to 70 mph, with a lesser threat of large hail. There is also a non-zero threat of isolated tornadoes in areas closer to the Kansas and Missouri borders this evening. A complex of severe storms is expected to develop over south central Kansas and north central Oklahoma by early this evening, and will move southeast across northeast Oklahoma and northwest Arkansas during the evening and tonight. Very strong instability and strong wind shear will favor organized and potentially significant severe weather, perhaps as far south as I-40, with lesser chances to the south. Thunderstorms will continue to push into southeastern Oklahoma and west central Arkansas through late tonight. Dangerous heat is ongoing this afternoon across much of eastern Oklahoma and west central Arkansas, with heat index values in the 110 to 116 degree range. An Excessive Heat Warning is in effect for much of the area through 9 pm this evening. Conditions will improve by late evening as temperatures cool, and thunderstorms begin to push into the area. SPOTTER AND EMERGENCY MANAGEMENT ACTION STATEMENT... Activation of the Regional Spotter Network Expected. .DAYS TWO THROUGH SEVEN...Sunday through Friday. SUNDAY...Thunderstorm Potential...Dangerous Heat Potential. MONDAY...Dangerous Heat Potential. TUESDAY...Thunderstorm Potential...Dangerous Heat Potential. WEDNESDAY through FRIDAY...Dangerous Heat Potential. EXTENDED DISCUSSION... Thunderstorms are expected to continue to affect southeastern Oklahoma and west central Arkansas Sunday morning into the afternoon, as the cold front slowly passes through the region. There is a limited risk of severe weather with this activity. The heat will become the main concern next week, especially Tuesday through Friday with heat index values in the 100 to 110 degree range across eastern Oklahoma and western Arkansas during this time. weather.gov/tulsa contains additional information. 69
In the hours before
Special weather statement, Jul 11, 6:35 PM CDT, 22 minutes before
Special Weather Statement National Weather Service Tulsa OK 635 PM CDT Sat Jul 11 2020 OKZ057-058-062-063-120030- Craig OK-Delaware OK-Ottawa OK-Mayes OK- 635 PM CDT Sat Jul 11 2020 ...SIGNIFICANT WEATHER ADVISORY FOR BOATERS ON GRAND LAKE IN NORTHEAST OKLAHOMA... At 630 PM CDT, a large severe thunderstorm was moving south- southeast out of Kansas into northeast Oklahoma. This storm is expected to move across the Grand Lake area between 7pm and 8pm. PRECAUTIONARY/PREPAREDNESS ACTIONS... Boaters on Grand lake should closely follow information related to this storm and be ready to move to safe areas when warnings are issued. Campers around the lake should also be ready to move to safe locations. && A Severe Thunderstorm Watch remains in effect until 1100 PM CDT for northeastern Oklahoma. A Severe Thunderstorm Watch also remains in effect until 100 AM CDT for northeastern Oklahoma. LAT...LON 3677 9462 3650 9462 3641 9504 3670 9514 TIME...MOT...LOC 2329Z 340DEG 28KT 3701 9507
The office that day
Everything else NWS Tulsa, OK issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 11, 3:16 AM CDT | Heat Advisory | TSA | Choctaw, Craig, Creek, Haskell, Latimer, McIntosh and 12 more | 10 hr |
| Jul 11, 7:46 AM CDT | Special Weather Statement | TSA | Osage | 29 min |
| Jul 11, 8:15 AM CDT | Special Weather Statement | TSA | Osage | 45 min |
| Jul 11, 8:56 AM CDT | Special Weather Statement | TSA | Rogers, Washington | 34 min |
| Jul 11, 11:23 AM CDT | Excessive Heat Warning | TSA | Choctaw, Craig, Creek, Haskell, Latimer, McIntosh and 12 more | 10 hr |
| Jul 11, 1:05 PM CDT | Heat Advisory | TSA | Adair, Cherokee, Delaware, Ottawa | 8 hr |
| Jul 11, 5:54 PM CDT | Severe Thunderstorm Warning | TSA | Craig, Ottawa | 66 min |
| Jul 11, 6:35 PM CDT | Special Weather Statement | TSA | Delaware | 55 min |
| Jul 11, 6:55 PM CDT | Severe Thunderstorm Warning | TSA | Craig | 50 min |
Nearby
Severe Thunderstorm Warnings in Oklahoma, 2020Every severe thunderstorm warning in 2020
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.