Severe thunderstorms erupted for a second straight day across the South Plains. A large upper level low over the western United States allowed for low level moisture to remain in the region under low level southeasterly flow.
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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 LUB wrote it up.
Severe thunderstorms erupted for a second straight day across the South Plains. A large upper level low over the western United States allowed for low level moisture to remain in the region under low level southeasterly flow. A weak short wave moved out of central New Mexico into West Texas during the afternoon hours which aided in convective development along a dryline. Two general areas of convection matured into severe thunderstorms: one in the southwestern Texas Panhandle and another in the southern South Plains into the Permian Basin. Although there was no initial development in the central South Plains, this area saw the largest hail of the afternoon. Storms across the extreme southwestern Texas Panhandle generally produced hail up to ping pong ball size. At the same time, a severe thunderstorm near Post (Garza County) produced hail up to tennis ball size. The initial thunderstorms in the southern South Plains generated an outflow boundary that surged northward lifting very unstable air. Multi cellular thunderstorms developed along this outflow boundary in Lynn County but quickly moved northward into Lubbock County. One of these storms took on a anticyclonic circulation as it moved into southern Lubbock County. This storm would go on to produce a widespread swath of hail with sizes generally between hen eggs and tennis balls. The largest hailstone observed was three inches in diameter around the intersection of Quaker Ave. and 114th Street. The swath of giant hail began on the south side of the city of Lubbock (Lubbock County) and ended around Lubbock Preston Smith International Airport (Lubbock County). One of the other thunderstorms that developed on the outflow boundary also produced severe hail at the same time over the western portion of Lubbock County. This swath of hail was observed from just east of Wolfforth (Lubbock County) to Texas Tech University (Lubbock County) and consisted of hail mostly around golf ball size. Total damages in Lubbock County were estimated at $100 million due to substantial and widespread roof and vehicle damage.
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 Lubbock, TX wrote its last area forecast discussion before the first event at May 20, 1:34 PM CST, 2 hours 16 minutes earlier.
Area Forecast Discussion National Weather Service Lubbock TX 234 PM CDT Wed May 20 2020 .SHORT TERM... Little change in the forecast from this mornings update in regards to afternoon/evening convection... Upper level shortwave will make its way into our CWA later this afternoon helping with destabilization. At the surface a dryline rests near the TX/NM line with E-SE flow across much of our CWA helping to maintain 60 dewpoints through much of our area. Later this afternoon surface dynamics and accompanying downslope winds will aid in the development of a deep lee surface low across the TX/NM border. This will effectively force the dryline into our far western counties. The expectation is that the dryline will sharpen and provide the surface lift necessary for thunderstorm development. CAMs now showing a later initiation time around 4pm CDT near and west of I27. Large hail up to hen eggs (2 inches) remains justified give large CAPEs and severe parameters. DCAPE values suggest strong wind gusts as high as 70 mph will also be possible. This afternoons PWs will be greater than 150% of normal. This along with our moderate vertical wind shear values and veering winds indicate flash flooding could be an issue especially across low water crossings and flood prone areas. Storms will slowly exit the CWA tonight with CDS seeing the last of the activity after midnight. Behind today's activity overnight will be mild with lows dropping into the 60s. Tomorrow, the flow aloft and at the surface become SWRLY with the development of a lee-side surface low in the afternoon. This scenario will advect warm dry air into the CWA warming high temperatures into the 90s for much of the area. SW flow aloft and at the surface will also act as a forcing mechanism that will drive the dryline to our eastern borders tomorrow afternoon. Dryline convection could occur across the very far eastern Rolling Plains or just to our east. .LONG TERM... No major changes in the extended forecast which features several opportunities for thunderstorms and severe weather. As alluded to above, the dryline will likely reside off the Caprock tomorrow afternoon/evening, where it could spark isolated late day convection. If storms can initiate locally, there will be a severe weather risk. Friday will be fairly similar, though a weak convectively aided front may dip into the northern South Plains early in the day. This front will tend to wash out in the afternoon with the dryline likely mixing back into the Rolling Plains. Thus there will be a chance for late day convection again on Friday over the eastern zones, though it could be just outside of the CWA if some of the guidance is correct. As the western trough reloads late week into early this weekend, backing southwesterly flow aloft and surface pressure falls in the lee of the Rockies should result in the dryline making less eastward headway. Current projections have the dryline roughly bisecting the FA from NNE to SSW by peak heating, where it could provide forcing for isolated to scattered afternoon/evening convection. The western trough will translate eastward, emerging over the High Plains late Sunday. This will send a cold front southward into the South Plains Sunday afternoon or night. T-storms will likely erupt as the front interacts with the Gulf moisture along of and ahead of the dryline, which again is forecast to be positioned N-S somewhere in the center of the FA. Cooler temperatures and a bout of stratus will follow on Labor Day. Depending on the timing for the front and passing upper trough, shower/storm chances could linger into early next week. This will be highly dependent on if/where an upper low cuts off from the flow, which currently varies from somewhere over/near West Texas to Kansas, Oklahoma or East Texas. Obviously, there is a lot to be worked out here, but we have maintained decreasing rain/storm chances from Monday through Tuesday, with sub- mentionable PoPs thereafter. After a warm/hot start to the extended, temperatures will dip below average behind the FROPA on Monday. However temperatures should recover to near or even above average by the middle of next week...assuming a cutoff low doesn't throw down anchor overhead. && .LUB WATCHES/WARNINGS/ADVISORIES... None. && 28/23
Hazardous Weather Outlook National Weather Service Lubbock TX 1120 AM CDT Wed May 20 2020 TXZ021>044-211630- Parmer-Castro-Swisher-Briscoe-Hall-Childress-Bailey-Lamb-Hale-Floyd- Motley-Cottle-Cochran-Hockley-Lubbock-Crosby-Dickens-King-Yoakum- Terry-Lynn-Garza-Kent-Stonewall- 1120 AM CDT Wed May 20 2020 This Hazardous Weather Outlook is for the South Plains, Rolling Plains and the far Southern Texas Panhandle. .DAY ONE...This afternoon and tonight. Scattered strong to severe thunderstorms will develop this afternoon over areas on the Caprock, with activity moving into the Rolling Plains during the evening. Thunderstorms later today will have potential for hail to two inches in diameter, wind gusts to 70 mph, and localized intense rain and flooding will also be possible. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday. Thunderstorms will be possible this weekend and into early next week, some of which may be severe. .SPOTTER INFORMATION STATEMENT... Spotter activation will likely be needed. Please relay any information about severe weather to the NWS while following local, state, and CDC guidelines.
The Amarillo radar (KAMA), 101 km away, was scanning. The volume nearest the first event began at 21:48 UTC.
9 hail. Local standard time, as filed.
A couple of reports were received of hail up to ping pong ball size along Texas Highway 86 west of Dimmitt.
A swath of tennis ball size hail was observed from about three miles northwest of Post to about five miles north of Post. No damage was reported.
A public report was received of quarter size hail between Hart and Dimmitt along Texas Highway 194.
A thunderstorm developed along an outflow boundary in Lynn County and rapidly grew into a severe supercell thunderstorm as it moved northward toward the city of Lubbock. This storm quickly began to rotate anticyclonically as it moved into the southern portion of Lubbock County. As the storm entered the southern portion of the city of Lubbock numerous reports were initially received of hail up to baseball size. The largest hail stone reported was three inches in diameter. The storm continued to move northward through the central part of the city producing hail up to tennis ball size. The swath of giant hail ended around Lubbock Preston Smith International Airport at 1819 CST. While this initial storm was affecting the central portion of the city, a second severe thunderstorm developed over Wolfforth and moved to the northeast. This storm produced hail up to two inches in diameter from just east of Wolfforth to Texas Tech University. In the aftermath, numerous vehicles and roofs on homes were damaged, primarily from the initial thunderstorm that moved through the central part of Lubbock. Total losses were estimated at over $100 million.
A report from the public was received of half dollar size hail in Abernathy. This was from the same thunderstorm that produced three inch diameter hail in Lubbock.
A public report was received of half dollar size hail in Roundup.
A report was received of quarter size hail approximately ten miles south of Plainview.
A report was received of ping pong ball size hail along US Highway 70 east of Plainview.
A county official measured quarter size hail three miles south of Estelline.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Texas in 2020Every state in 2020This day in weather historyWarnings in Texas, May 2020
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: 885044, 885047, 885051, 885048, 885049, 885050, 885052, 885053, 885054.