SPC
SPC PDS Tornado Watch 277
WW 277 TORNADO IA IL MN WI 211810Z – 220200Z 
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 277 NWS Storm Prediction Center Norman OK 110 PM CDT Tue May 21 2024 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Iowa Northwest Illinois Southeast Minnesota Western Wisconsin * Effective this Tuesday afternoon and evening from 110 PM until 900 PM CDT. ...THIS IS A PARTICULARLY DANGEROUS SITUATION... * Primary threats include... Several tornadoes and a few intense tornadoes likely Widespread damaging winds and isolated significant gusts to 90 mph likely Scattered large hail likely with isolated very large hail events to 4 inches in diameter possible SUMMARY...An increasingly volatile environment and very strong atmospheric winds are expected to yield an outbreak of severe storms including tornadoes and widespread damaging winds across the region through the afternoon and early evening. The tornado watch area is approximately along and 110 statute miles east and west of a line from 30 miles south southwest of Ottumwa IA to 50 miles northeast of Mankato MN. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). 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 276... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 4 inches. Extreme turbulence and surface wind gusts to 80 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 22045. ...Guyer
SPC Tornado Watch 276
WW 276 TORNADO IA MO NE SD 211610Z – 212200Z 
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 276 NWS Storm Prediction Center Norman OK 1110 AM CDT Tue May 21 2024 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Western Iowa Northwest Missouri Eastern Nebraska Southeast South Dakota * Effective this Tuesday morning and afternoon from 1110 AM until 500 PM CDT. * Primary threats include... A few tornadoes and a couple intense tornadoes possible Scattered large hail likely with isolated very large hail events to 3 inches in diameter possible Scattered damaging wind gusts to 70 mph likely SUMMARY...The atmosphere is expected to rapidly become favorable for severe storm development, including the potential for tornadoes, through early/mid-afternoon. The tornado watch area is approximately along and 60 statute miles east and west of a line from 55 miles west northwest of Spencer IA to 25 miles west of Falls City NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). 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 275... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 22035. ...Guyer
SPC Severe Thunderstorm Watch 275
WW 275 SEVERE TSTM IA 211115Z – 211800Z 
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 275 NWS Storm Prediction Center Norman OK 615 AM CDT Tue May 21 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Central and southern Iowa * Effective this Tuesday morning and afternoon from 615 AM until 100 PM CDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 75 mph possible Isolated large hail events to 1.5 inches in diameter possible A tornado or two possible SUMMARY...Clusters of thunderstorms -- including an organized bowing complex initially over eastern NE -- will pose a threat mainly for severe gusts while crossing the watch area from west to east. A tornado or two cannot be ruled out, especially near an outflow boundary draped across central/south-central IA. Isolated large hail is possible. This is a precursor to the main severe-weather threat expected later today, for which we have a "Moderate Risk" outlook. The severe thunderstorm watch area is approximately along and 60 statute miles north and south of a line from 80 miles west of Des Moines IA to 25 miles south southeast of Cedar Rapids IA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for 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. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 274... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 26045. ...Edwards
SPC Severe Thunderstorm Watch 274
WW 274 SEVERE TSTM IA KS NE 210430Z – 211200Z 
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 274 NWS Storm Prediction Center Norman OK 1130 PM CDT Mon May 20 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Extreme western Iowa Extreme north central Kansas Central into eastern Nebraska * Effective this Monday night and Tuesday morning from 1130 PM until 700 AM CDT. * Primary threats include... Widespread damaging winds and isolated significant gusts to 75 mph likely Scattered large hail events to 1.5 inches in diameter likely A tornado or two possible SUMMARY...Ongoing storms with a hail/wind threat may persist for a couple more hours across eastern Nebraska/western Iowa, while storms well to the west will grow upscale into a larger/bowing convective system overnight into central then eastern Nebraska. Damaging wind swaths up to 75 mph will be the main threat, along with large hail up to 1.5 inches in diameter and a tornado or two with embedded circulations. The severe thunderstorm watch area is approximately along and 65 statute miles north and south of a line from 60 miles south southwest of Broken Bow NE to 20 miles northeast of Omaha NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU4). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for 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. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...This severe thunderstorm watch replaces severe thunderstorm watch number 271. Watch number 271 will not be in effect after 1130 PM CDT. CONTINUE...WW 269...WW 272...WW 273... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 25035. ...Thompson
SPC Tornado Watch 273
WW 273 TORNADO CO KS NE 210155Z – 210800Z 
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 273 NWS Storm Prediction Center Norman OK 855 PM CDT Mon May 20 2024 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Extreme northeast Colorado Extreme northwest Kansas Southwest Nebraska * Effective this Monday night and Tuesday morning from 855 PM until 300 AM CDT. * Primary threats include... A few tornadoes likely with a couple intense tornadoes possible Scattered damaging winds and isolated significant gusts to 80 mph likely Scattered large hail and isolated very large hail events to 3 inches in diameter likely SUMMARY...Clusters of intensifying supercells across northeast Colorado will continue eastward into Kansas/Nebraska with some potential for upscale growth tonight. The storm environment will favor all significant hazards of all types (tornadoes capable of EF2 damage, very large hail up to 3 inches in diameter, and severe outflow winds up to 80 mph). The tornado watch area is approximately along and 55 statute miles north and south of a line from 25 miles west of Imperial NE to 35 miles northeast of Mccook NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU3). 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 268...WW 269...WW 270...WW 271...WW 272... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 70 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27030. ...Thompson