Alert archive / Oklahoma / Mesoscale Discussions in 2017
Mesoscale Discussion 769
The Storm Prediction Center issued this mesoscale discussion at May 18, 2017, 7:19 PM CDT for 5 counties in Oklahoma. It was in force for 26 min.
The area
The outline as issued.
The facts
- Issued
- May 18, 2017, 7:19 PM CDT (00:19 UTC)
- Expired
- May 18, 2017, 7:45 PM CDT
- In force
- 26 min
- Issued by
- the Storm Prediction Center
Counties Alfalfa County, OK, Garfield County, OK, Grant County, OK, Major County, OK, Woods County, OK
The radar
The Vance AFB radar (KVNX), 33 km from the middle of the area, began a volume at 00:22 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.
The watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Dodge City, (KDDC), launched 00:00Z, 0.3 hours before the alert went out and 223 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
- 11 J/kg
- Mixed-layer CIN
- -229 J/kg
- Mixed-layer LCL
- 808 m above ground
- 0-6 km bulk shear
- 93 kt
- 0-1 km storm-relative helicity
- 349 m²/s²
- 0-3 km storm-relative helicity
- 249 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.3
The text
As transmitted.
161 ACUS11 KWNS 190020 SWOMCD SPC MCD 190019 OKZ000-KSZ000-190045- Mesoscale Discussion 0769 NWS Storm Prediction Center Norman OK 0719 PM CDT Thu May 18 2017 Areas affected...northwest and north-central OK Concerning...Tornado Watch 235... Valid 190019Z - 190045Z The severe weather threat for Tornado Watch 235 continues. SUMMARY...Large hail and severe gusts will become the main threats with storms over northern OK this evening. DISCUSSION...Radar mosaic shows several strong/severe thunderstorms across northwestern OK and farther east near I-35 in north-central OK. OK mesonet surface observations show considerable cooling of the boundary layer has occurred due to widespread convection. Surface temperatures are near 70 degrees F and dewpoints in the lower to middle 60s. As a result, moderate buoyancy still resides across the discussion area despite lessening boundary layer instability. While a tornado is possible over the next 30 minutes, it appears the primary severe hazards will continue to transition to hail (possibly wind-driven) and severe gusts with the stronger storms. ..Smith.. 05/19/2017 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ICT...OUN...DDC... LAT...LON 36189757 36089960 37069862 36909735 36389728 36189757
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 18, 7:43 PM CDT | Mesoscale Discussion | SPC | Carter, Jefferson, Johnston, Love, Murray, Pontotoc | 62 min |
| May 18, 7:47 PM CDT | Severe Thunderstorm Watch | SPC | Alfalfa, Atoka, Bryan, Canadian, Carter, Cleveland and 26 more | 6 hr |
| May 18, 9:41 PM CDT | Mesoscale Discussion | SPC | Adair, Cherokee, Craig, Delaware, Haskell, Latimer and 4 more | 94 min |
| May 19, 10:41 AM CDT | Mesoscale Discussion | SPC | Carter, Jefferson, Love, Marshall | 94 min |
| May 19, 2:13 PM CDT | Mesoscale Discussion | SPC | Adair, Ottawa, Sequoyah | 92 min |
| May 19, 3:26 PM CDT | Tornado Watch | SPC | Adair, Atoka, Bryan, Carter, Cherokee, Choctaw and 19 more | 11 hr |
| May 19, 3:28 PM CDT | Mesoscale Discussion | SPC | Grant, Kay | 92 min |
| May 19, 4:47 PM CDT | Tornado Watch | SPC | Alfalfa, Grant, Kay | 4 hr |
| May 19, 6:56 PM CDT | Mesoscale Discussion | SPC | Adair, Atoka, Bryan, Carter, Cherokee, Choctaw and 24 more | 2 hr |
Nearby
Mesoscale Discussions in Oklahoma, 2017Every mesoscale discussion 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.