Alert archive / Arkansas / Tornado Watches in 2017
Tornado Watch 50
The Storm Prediction Center issued this tornado watch at Feb 28, 2017, 11:35 PM CST for 30 counties in Arkansas; 19 counties in Oklahoma. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 28, 2017, 11:35 PM CST (05:35 UTC)
- Expired
- Mar 1, 2017, 4:18 AM CST
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 49 counties
Baxter County, AR, Boone County, AR, Cleburne County, AR, Conway County, AR, Crawford County, AR, Faulkner County, AR, Franklin County, AR, Fulton County, AR, Howard County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Johnson County, AR, Logan County, AR, Marion County, AR, Montgomery County, AR, Newton County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pope County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Sevier County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Yell County, AR, Atoka County, OK, Bryan County, OK, Carter County, OK, Choctaw County, OK, Coal County, OK, Haskell County, OK, Hughes County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, Love County, OK, Marshall County, OK, McCurtain County, OK, McIntosh County, OK, Murray County, OK, Pittsburg County, OK, Pontotoc County, OK, Pushmataha County, OK, Sequoyah County, OK
The radar
The Western Arkansas radar (KSRX), 48 km from the middle of the area, began a volume at 05:37 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 SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
13 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 28, 11:37 PM CST | Severe Thunderstorm Warning | OUN | Coal, Hughes, Pontotoc | 38 min |
| Feb 28, 11:50 PM CST | Severe Thunderstorm Warning | TSA | Pittsburg | 40 min |
| Mar 1, 12:12 AM CST | Severe Thunderstorm Warning | OUN | Atoka, Coal | 48 min |
| Mar 1, 12:19 AM CST | Severe Thunderstorm Warning | TSA | Latimer, Pittsburg | 56 min |
| Mar 1, 12:47 AM CST | Severe Thunderstorm Warning | TSA | Crawford, Franklin, Sebastian | 43 min |
| Mar 1, 12:49 AM CST | Severe Thunderstorm Warning | TSA | Latimer, LeFlore, Pittsburg, Pushmataha | 41 min |
| Mar 1, 12:52 AM CST | Severe Thunderstorm Warning | TSA | Haskell, Latimer, LeFlore | 38 min |
| Mar 1, 1:07 AM CST | Severe Thunderstorm Warning | LZK | Johnson, Logan, Newton, Pope, Searcy, Yell | 38 min |
| Mar 1, 1:09 AM CST | Severe Thunderstorm Warning | TSA | Crawford, Franklin, Madison, Sebastian | 36 min |
| Mar 1, 1:39 AM CST | Severe Thunderstorm Warning | LZK | Baxter, Conway, Johnson, Logan, Marion, Newton and 4 more | 51 min |
| Mar 1, 2:27 AM CST | Severe Thunderstorm Warning | LZK | Baxter, Cleburne, Conway, Faulkner, Independence, Izard and 6 more | 48 min |
| Mar 1, 2:43 AM CST | Severe Thunderstorm Warning | LZK | Baxter, Fulton, Izard, Sharp | 47 min |
| Mar 1, 3:05 AM CST | Severe Thunderstorm Warning | LZK | Independence, Jackson, Sharp, White, Woodruff | 40 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Springfield, MO (KSGF), launched 00:00Z, 5.6 hours before the alert went out and 224 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
- 1117 J/kg
- Mixed-layer CIN
- -52 J/kg
- Mixed-layer LCL
- 931 m above ground
- 0-6 km bulk shear
- 65 kt
- 0-1 km storm-relative helicity
- 341 m²/s²
- 0-3 km storm-relative helicity
- 315 m²/s²
- Significant tornado parameter
- 2.3
- Supercell composite
- 8.2
The text
As transmitted.
618 WWUS20 KWNS 010533 SEL0 SPC WW 010533 ARZ000-OKZ000-011200- URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 50 NWS Storm Prediction Center Norman OK 1135 PM CST Tue Feb 28 2017 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Western and northern Arkansas South-central and southeastern Oklahoma * Effective this Tuesday night and Wednesday morning from 1135 PM until 600 AM CST. * Primary threats include... A couple tornadoes possible Isolated very large hail events to 2 inches in diameter possible Isolated damaging wind gusts to 70 mph possible SUMMARY...Convection is increasing in coverage and intensity ahead of a cold front over parts of southern and southeastern OK, and should move eastward to east-northeastward. Activity will cross a favorable cape/shear parameter space for supercells and small bows with a risk of all severe-storm hazards. See SPC mesoscale discussion 230 for initial meteorological details. The tornado watch area is approximately along and 50 statute miles north and south of a line from 10 miles south of Ardmore OK to 25 miles north northeast of Batesville AR. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && OTHER WATCH INFORMATION...CONTINUE...WW 44...WW 45...WW 46...WW 47...WW 48...WW 49... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24035. ...Edwards
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 28, 7:46 PM CST | Mesoscale Discussion | SPC | Baxter, Clay, Cleburne, Craighead, Cross, Fulton and 14 more | 119 min |
| Feb 28, 8:29 PM CST | Tornado Watch | SPC | Clay, Craighead, Greene, Lawrence, Mississippi, Poinsett and 1 more | 12 hr |
| Feb 28, 9:04 PM CST | Tornado Watch | SPC | Benton, Carroll, Madison, Washington | 7 hr |
| Feb 28, 10:46 PM CST | Mesoscale Discussion | SPC | Boone, Carroll, Conway, Crawford, Franklin, Garland and 20 more | 119 min |
| Mar 1, 2:09 AM CST | Mesoscale Discussion | SPC | Arkansas, Clark, Clay, Cleburne, Cleveland, Conway and 38 more | 2 hr |
| Mar 1, 3:03 AM CST | Tornado Watch | SPC | Clay, Craighead, Crittenden, Cross, Greene, Lawrence and 4 more | 5 hr |
| Mar 1, 4:19 AM CST | Mesoscale Discussion | SPC | Crittenden | 56 min |
| Feb 28, 10:01 PM CST | Mesoscale Discussion | SPC | Craig, Delaware, Mayes, Nowata, Osage, Ottawa and 4 more | 119 min |
Nearby
Tornado Watches in Arkansas, 2017Tornado Watches in Oklahoma, 2017Every tornado watch 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.