History of Storm Prediction Center in Timeline

The Storm Prediction Center (SPC) is a United States government agency nested within the National Centers for Environmental Prediction (NCEP), the National Weather Service (NWS), and the National Oceanic and Atmospheric Administration (NOAA), ultimately under the Department of Commerce (DoC). The SPC's core function is to forecast severe weather events, particularly tornadoes, severe thunderstorms, and related hazards, across the contiguous United States. It provides forecasts and warnings to inform the public, emergency management agencies, and other stakeholders about potential severe weather risks, playing a critical role in mitigating damage and saving lives.

1952: Severe Local Storms Unit (SELS) Established

In 1952, the Storm Prediction Center began as the Severe Local Storms Unit (SELS) within the U.S. Weather Bureau in Washington, D.C.

1954: SELS Moved to Kansas City

In 1954, the Severe Local Storms Unit moved its forecast operations to Kansas City, Missouri.

1955: SELS Issued Convective Outlooks

In 1955, the Severe Local Storms Unit began issuing convective outlooks for predicted thunderstorm activity.

1960: SELS Issued Radar Summaries

In 1960, the Severe Local Storms Unit began issuing radar summaries in three-hour intervals.

1966: SELS Became NSSFC

In 1966, the Severe Local Storms Unit became the National Severe Storms Forecast Center (NSSFC) due to increased duties, remaining headquartered in Kansas City.

1968: NSSFC Issued Status Reports on Weather Watches

In 1968, the National Severe Storms Forecast Center began issuing status reports on weather watches.

1971: First Computerized Data Transmission

In 1971, the National Severe Storms Forecast Center made its first computerized data transmission.

April 2, 1982: First "Particularly Dangerous Situation" Watch Issued

On April 2, 1982, the National Severe Storms Forecast Center issued the first "Particularly Dangerous Situation" watch, indicating an imminent threat of a major severe weather event.

1986: New Forecast Products Introduced

In 1986, the National Severe Storms Forecast Center introduced two new forecast products: the Day 2 Convective Outlook and the Mesoscale Discussion.

October 1995: NSSFC Relocated and Renamed SPC

In October 1995, the National Severe Storms Forecast Center relocated to Norman, Oklahoma, and was renamed the Storm Prediction Center.

1998: National Fire Weather Outlook Issued

In 1998, the Storm Prediction Center began issuing the National Fire Weather Outlook to provide forecasts for areas susceptible to wildfires.

2000: Experimental Day 3 Convective Outlook

In 2000, the Day 3 Convective Outlook was first issued on an experimental basis.

2001: Official Day 3 Convective Outlook

In 2001, the Day 3 Convective Outlook was made an official product.

April 7, 2006: Day 2 High Risk Issued

On April 7, 2006, a Day 2 high risk was issued by the Storm Prediction Center.

2006: SPC Moved to National Weather Center

In 2006, the Storm Prediction Center moved its operations into the newly constructed National Weather Center in Norman, Oklahoma.

March 22, 2007: Day 4-8 Outlook Became Official Product

On March 22, 2007, the Storm Prediction Center incorporated the Day 4–8 outlook as an official product.

April 1, 2009: Product Issuance Responsibilities Reassigned

On April 1, 2009, the Storm Prediction Center reassigned responsibilities for issuing the center's products in outage situations to the 15th Operational Weather Squadron based out of Scott Air Force Base.

April 2011: Graphical updates for categorical levels of risk

In April 2011, the SPC introduced a new graphical format for its categorical and probability outlooks, which included the shading of risk areas and population, county/parish/borough and interstate overlays.

April 2011: New graphical format introduced

In April 2011, the Storm Prediction Center introduced a new graphical format for its categorical and probability outlooks, including the shading of risk areas and revised color palettes.

April 14, 2012: Day 2 High Risk Issued

On April 14, 2012, a Day 2 high risk was issued by the Storm Prediction Center.

June 2012: SPC Forecasts General Thunderstorm Risk Areas

As of June 2012, the SPC forecasts general thunderstorm risk areas.

2013: Table incorporated under Convective Outlook's risk category

In 2013, the SPC incorporated a small table under the Convective Outlook's risk category map that indicates the total coverage area by square miles, the total estimated population affected and major cities included within a severe weather risk area.

April 21, 2014: Public comment period for additions to the Convective Outlooks

On April 21, 2014, the Storm Prediction Center began asking for public comment on proposed categorical additions to the Day 1-3 Convective Outlooks for a two-month period.

October 2014: Marginal and enhanced risk categories added

Even after the marginal and enhanced risk categories were added in October 2014, some television stations have continued to use the original three-category system to outline forecasted severe weather risks.

October 22, 2014: Enhanced Risk Category Added

On October 22, 2014, the upper end of the SLGT category was replaced with the "ENH" category for enhanced risk.

January 28, 2020: Probabilities for tornadoes, hail and wind incorporated into the Day 2 Convective Outlook.

On January 28, 2020, probabilities for tornadoes, hail and wind applying to the Day 1 Convective Outlook were incorporated into the Day 2 Convective Outlook. The individual hazard probabilistic forecasts replaced the existing "total severe" probability graph for general severe convective storms that had been used for the Day 2 outlook beforehand.

January 28, 2020: Specific probabilities for tornadoes, hail, or wind issued for Day 1 outlook.

Prior to January 28, 2020, the Day 1 was currently the only outlook to issue specific probabilities for tornadoes, hail or wind. The Day 1 Convective Outlook provides a textual forecast, map of categories and probabilities, and chart of probabilities.

August 13, 2024: Day 3 Outlooks Issued Twice Daily

Since August 13, 2024, Day 3 outlooks are issued twice daily at 0730Z in Daylight Saving Time or 0830Z in Standard Time and 1930Z.

March 15, 2025: Day 2 High Risk Issued

On March 15, 2025, a Day 2 high risk was issued by the Storm Prediction Center.

March 2025: DOGE Announced NOAA Office Terminations

During March 2025, the Department of Government Efficiency (DOGE) had announced other NOAA office terminations.

March 2025: Number of Meso-Gamma Mesoscale Discussions Issued

As of March 2025, the Storm Prediction Center has issued 44 meso-gamma mesoscale discussions.

March 17, 2025: Report of SPC Closure

On March 17, 2025, ABC News reported, from an anonymous source, that the Storm Prediction Center was set to be closed by the Department of Government Efficiency (DOGE).

April 28, 2025: Day 3 Moderate Risk Issued

On April 28, 2025, a Day 3 moderate risk was issued by the Storm Prediction Center. These have been issued only twenty-two times since the product became operational.