Severe thunderstorms developed in multiple waves along a surface dry line during the afternoon and evening hours on April 21st. Large hail was the primary severe weather which occurred, especially over portions of Collin County, where hail damaged several jurisdictions in and around McKinney.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS FWD wrote it up.
Severe thunderstorms developed in multiple waves along a surface dry line during the afternoon and evening hours on April 21st. Large hail was the primary severe weather which occurred, especially over portions of Collin County, where hail damaged several jurisdictions in and around McKinney.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Fort Worth, TX wrote its last area forecast discussion before the first event at Apr 20, 10:18 PM CST, 3 hours 27 minutes earlier.
Area Forecast Discussion National Weather Service Fort Worth TX 1118 PM CDT Thu Apr 20 2017 .AVIATION... Convection has erupted and will continue to erupt across Oklahoma overnight as a mid level shortwave moves into the Southern Plains. Storms will be focused mainly in the vicinity of a stationary front, which should remain draped across northwest Texas and Oklahoma for the rest of the night. A couple of right-moving supercells have the potential to cross the Red River in the next few hours, but these storms should still remain north of TAF locations during the overnight hours. As the shortwave moves farther east on Friday, the front will surge south, bringing with it a round of showers and storms in the DFW area likely in the 02-04 Z time frame Friday evening. Activity will attempt to backbuild southwest towards the Waco area, which may lead to an isolated storm or two near KACT after 22/06Z. Ahead of the system, we should see another round of MVFR stratus develop and spread quickly north across the area. MVFR conditions first thing Friday morning will gradually improve throughout the day, becoming VFR by mid Friday afternoon. 30 && .UPDATE... At 9pm a surface frontal boundary was nearly stationary to the northwest of Wichita Falls and draped across southern Oklahoma. There were a few convective attempts to the south of the front earlier this evening, but capping and insufficient forcing led to their quick demise. Since then, as stronger forcing for ascent has spread into the Southern Plains ahead of a shortwave trough, and strengthening low level warm advection spreads north, there has been a marked increase in elevated showers and thunderstorms across Oklahoma, north of the frontal boundary. This activity should continue for much of the nighttime hours, with most of the activity remaining north of the Red River through Friday morning. For the remainder of tonight, we have lowered PoPs across our northwest counties and confined rain/storm chances to the immediate Red River area after midnight. Lapse rates will steepen through the nighttime hours as temperatures cool aloft with the approaching trough. This will support a severe hail threat with any storms. Other than some minor changes to PoPs for tonight, no other changes needed to the current forecast. Dunn && .PREV DISCUSSION... /ISSUED 345 PM CDT Thu Apr 20 2017/ At mid afternoon, a frontal boundary extended southeast of a line from Rogers, Arkansas to Muskogee, Oklahoma to Frederick, Oklahoma to Big Spring, Texas. Scattered showers and thunderstorms so far today has been across eastern part of this front from Central Oklahoma northeastward. How far south this boundary moves is dependent on the convection that develops along the front. For now, have indicated that this front will become stationary southeast of a McAlester, Oklahoma to Wichita Falls line late this evening before it then start to lift back to the north. A few storms may reach areas north of a Cisco to Denton to Paris line tonight. If these storms occur, they will have the potential to become severe producing one inch hail and 60 mph wind gusts. Low clouds will overspread much of the forecast area again overnight tonight. Lows will be in the 60s. After morning low clouds, skies will become partly sunny Friday and highs will once again be well above normal with 80s expected area wide. There will be low chances of showers and thunderstorms Friday morning through mid afternoon mainly near the Red River. As a shortwave moves out into the Plains Friday afternoon, the cold front move southeast and thunderstorms chances will increase late Friday afternoon along and north of the I-20 corridor. Some severe thunderstorms will be possible with large hail and damaging winds as well as heavy rain and cloud to ground lightning. The storms are expected to develop into a squall line Friday night which will then sweep across much of the forecast area. The threat for damaging winds, locally heavy rain and cloud to ground lightning will continue through the night. Thunderstorm chances will linger southeast of a Killeen to Sulphur Springs line into early Saturday morning but the severe threat should be ending around daybreak as the cold front clears the region. Skies will clear from northwest to southeast during the day Saturday. It will be breezy and cool Saturday behind the front with highs in the 60s to lower 70s. Wind speeds will decrease to 5 to 10 mph toward sunset. With clear skies and these lighter winds, temperatures will fall into the 40s area wide by daybreak Sunday. Upper level ridging will occur Sunday and Monday in the wake of the departing upper level trough. The upper flow will become more zonal by Tuesday as shortwaves move across the northern and central Plains. This will result in dry weather through this period with warming trend starting during the day Sunday. Highs will be in the upper 60s to mid 70s Sunday, mid 70s to lower 80s Monday, and 80s to lower 90s Tuesday and Wednesday. Lows will still be cool Sunday night with lows mostly in the 40s, but will moderate Monday and Tuesday nights with mid 50s to lower 60s Monday night and 60s area wide Tuesday night. An upper level trough is expected to move out into northern and central Plains on Thursday, this should drive a cold front southward toward North Texas. Although the GFS, ECMWF and Canadian differ on their solutions, shower and thunderstorm chances should return on Thursday. 58 && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 69 82 55 67 47 / 5 20 60 10 0 Waco 67 82 56 67 45 / 5 5 40 10 0 Paris 64 80 53 64 44 / 10 20 70 10 0 Denton 66 82 52 67 45 / 5 30 60 5 0 McKinney 67 81 54 65 46 / 5 20 60 10 0 Dallas 69 83 56 68 49 / 5 20 60 10 0 Terrell 66 81 55 67 46 / 5 5 50 10 5 Corsicana 66 82 57 67 46 / 5 5 50 20 5 Temple 66 83 57 68 48 / 5 5 40 10 0 Mineral Wells 64 85 51 67 43 / 5 20 40 5 0 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && 30/91
Hazardous Weather Outlook National Weather Service Fort Worth TX 244 PM CDT Thu Apr 20 2017 TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-211200- Montague-Cooke-Grayson-Fannin-Lamar-Young-Jack-Wise-Denton-Collin- Hunt-Delta-Hopkins-Stephens-Palo Pinto-Parker-Tarrant-Dallas- Rockwall-Kaufman-Van Zandt-Rains-Eastland-Erath-Hood-Somervell- Johnson-Ellis-Henderson-Comanche-Mills-Hamilton-Bosque-Hill-Navarro- Freestone-Anderson-Lampasas-Coryell-Bell-McLennan-Falls-Limestone- Leon-Milam-Robertson- 244 PM CDT Thu Apr 20 2017 This Hazardous Weather Outlook is for North and Central Texas. .DAY ONE...Tonight. A chance of thunderstorms exists mainly north/northwest of a Breckenridge to Decatur to Sherman line. An isolated storm may briefly produce hail up to one inch and strong gusty winds .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Storm chances will once again increase late Friday afternoon into Saturday as a cold front moves south from Oklahoma into North and Central Texas. As storms initially develop, there will be a chance of large hail and damaging winds. The storms are expected to grow upscale and eventually form into a line which will move southeast into North Texas. Once a line of storms develops, the main threats will be damaging winds and heavy rain. As the cold front continues to move southward, severe storms will continue to be possible early Saturday morning, especially southeast of a Sulphur Springs to Corsicana to Killeen line. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
The Dallas/Ft Worth radar (KFWS), 125 km away, was scanning. The volume nearest the first event began at 07:45 UTC.
48 hail, 2 thunderstorm wind, 1 tornado. Local standard time, as filed.
The Montague County emergency manager reported quarter sized hail at the intersection of Lone Star Road and Phillips Road.
Nocona Fire Department reported quarter sized hail approximately 8 miles north of Nocona on Farm to Market Road 1759.
Nocona Fire Department reported half dollar sized hail near Lake Nocona.
Trained spotters reported quarter sized hail north of Muenster.
The Cooke County emergency manager reported egg sized hail north of Muenster.
A social media report indicated baseball sized hail in the city of Gainesville, TX.
Multiple spotters reported a rain wrapped tornado to the northwest of Valley View, and west of I-35. This tornado produced minimal damage over open farm and ranch land.
Baseball sized hail was reported on I-35 on the south side of Gainesville.
Ping pong ball sized hail was reported to the southeast of Gainesville.
A trained spotter reported quarter sized hail approximately 3 miles southeast of Lindsay.
A report of half dollar hail was received.
Emergency management relayed a spotter report of hen-egg sized hail approximately 5 miles northwest of the city of Tioga, TX.
An amateur radio operator reported quarter size hail in the city of Ranger.
The Grayson County emergency manager reported a wind gust estimated at 60 mph just south of Tioga.
An amateur radio operator reported a measured 60 mph wind gust on the south side of Lake Ray Roberts.
Storm spotter reported ping pong hail size approximately 4 miles WSW of Celina.
A social media user reported 2.50 inch hail near Prosper/Celina area.
Social Media reported egg size hail SE of Celina.
Fire Department reported golf ball size hail in Lingleville Fire Station.
An amateur radio operator reported baseball size hail just east of Prosper.
An storm spotter reported golf ball size hail in Celina.
Social media reported golf ball size near Prosper.
Emergency Manager reported golf ball size hail in Mckinney.
Storm spotter reported ping pong size hail near the city of Telephone, TX.
An storm spotter reported baseball size hail 2 miles west of McKinney.
An storm spotter reported half dollar size hail near McKinney.
Storm Spotter reported quarter size hail south of Stephenville, TX.
An storm spotter reported quarter size hail near Aledo.
Storm Spotter reported quarter size hail 3 miles NNW of Allen.
Storm Spotter reported tennis ball size hail near highway 121 and US 75.
Storm spotter reported quarter size hail 4 miles south/southwest of Gainesville.
An amateur radio reported golf ball size hail north/northwest of Lamar, in CR 32500 and FM 1499.
An amateur radio reported golf ball size hail near Paris, TX.
An amateur radio reported golf ball size hail in Caddo Mills, TX.
An amateur radio reported quarter size hail west of Denton, near the intersection of US 156 and 380.
An amateur radio reported quarter size hail near Robson Ranch, 2 miles north of Corral City.
Public report: half dollar size hail approximately 3 miles south/southwest of Denton.
Storm spotter reported quarter size hail in Royse City.
Social media (via Twitter) reported half dollar size hail near Highland Village.
Storm spotter reported half dollar size hail in Royse City.
Public reported golf ball size hail in Hebron, TX, in the intersection of King Arthur Blvd and N Josey Ln.
Media reported half dollar size hail near the Dallas Tollway and P. George Bush Turnpike approximate 7 miles west of Plano.
Trained Spotter reported golf ball size hail near P. George Bush Turnpike and Preston Road.
Trained Spotter reported ping pong size hail six miles southwest of Plano, near Preston Rd and Frankford Rd.
Trained spotter reported egg size hail 2 miles NNW of Richardson.
Emergency Manager reported golf ball size hail in central Plano.
Amateur Radio reported quarter size hail near Richardson.
Social Media reported up to egg size hail in Richardson.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Texas in 2017Every state in 2017This day in weather historyThe tornado archive for Texas, 2017Warnings in Texas, April 2017
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 692893, 692894, 692895, 692896, 692898, 693804, 692912, 681978, 692913, 692914, 692915, 692916, 693805, 693437, 693850, 692904, 692905, 693851, 693852, 693873, 693853, 693854, 693856, 693861, 693868, 693893, 693874, 693876, 693898, 693866, 693907, 693908, 693910, 693436, 693919, 693920, 693921, 693922, 693923, 693924, and more.