National Weather Service United States Department of Commerce

Stormy Weather in the Northwest; Fire Weather Threat Redeveloping in Southern California this Weekend

An active fall storm pattern in the Pacific Northwest is bringing heavy rain and high elevation snow to the region which will persist through this weekend. Strong winds associated with this system will bring a renewed period of critical fire weather to southern California later this weekend into next week. Read More >


Fast Facts

  • According to the latest information from the Oklahoma Department of Emergency Management, 3 people were killed and over 450 people were injured in the state during the tornado outbreak. More information can be found on the OEM Situation Update web page.

  • 56 tornadoes were documented in the state of Oklahoma, 36 of which were in the NWS Norman area of responsibility.

  • There were 2 EF4 tornadoes (the Moore-Lake Draper-Harrah and Norman-Little Axe-Pink tornadoes), and 4 EF3 tornadoes.

  • From 5:00 PM to 7:41 pm CDT, there was at least one tornado occurring in Oklahoma every minute. A total of 42 different tornadoes occurred within this time.

  • Between 5:33 PM and 5:59 PM CDT, there were between three and five tornadoes occurring simultaneously every minute. This includes a portion of the life cycle of 13 different tornadoes, including both EF4 tornadoes and two EF3 tornadoes.

  • A total of 31 Tornado Warnings (TOR), 19 Severe Thunderstorm Warnings (SVR), 95 Severe Weather Statements (SVS), 3 Warning Decision Updates (AWU), 12 Regional Weather Discussions (NOW) and 8 Significant Weather Advisories (SPS) were issued during the tornado outbreak. In addition, 22 Hazardous Weather Outlooks (HWO) mentioning the impending event were issued on May 4-10, 2010. A total of 8 multimedia weather briefings discussing the event were issued by NWS Norman on May 9-10, 2010.

  • The NWS Norman staff began to mention the possibility of a significant severe weather event on May 4, 2010. The Hazardous Weather Outlook used the included the sentence: "THERE ARE SOME INDICATIONS OF A POTENTIALLY SIGNIFICANT INCREASE IN THE RISK OF SEVERE WEATHER NEXT MONDAY." A Graphicast issued at 530 am CDT on May 4, 2010 also highlighted the potential for severe weather. Graphicast for 530 am CDT on May 4, 2010

  • The tornado damage paths are spread over a north-south area of over 200 miles from near the Kansas-Oklahoma border to near the Red River.

  • Very large hail was reported in several locations, up to the size of softballs (4.5").

Information Sources