1 / 12

Local Severe Weather Climatologies for WSR-88D Radar Areas across the United States

Local Severe Weather Climatologies for WSR-88D Radar Areas across the United States. John A. Hart NOAA/NWS/NCEP Storm Prediction Center Norman, Oklahoma. Introduction. Developed a climatology of severe weather reports (1980-2004) Useful due to equal areas of radar coverage regions.

Télécharger la présentation

Local Severe Weather Climatologies for WSR-88D Radar Areas across the United States

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Local Severe Weather Climatologies for WSR-88D Radar Areas across the United States John A. Hart NOAA/NWS/NCEP Storm Prediction Center Norman, Oklahoma

  2. Introduction • Developed a climatology of severe weather reports (1980-2004) • Useful due to equal areas of radar coverage regions. • Allows easy comparison between geographical regions.

  3. Methodology • Used the NWS/SPC severe weather database • Compiled reports within each WSR-88D radar coverage region for the period of record • Created graphs, tables, figures • Computed tornado threat probabilities based on tornado path width, length, and intensity ratings • Objectively determined primary severe weather season for each region. • NOTE: No additional quality-control. Data is plotted and tabulated directly from SPC database*. * Schaefer, J. T. and R. Edwards, 1999: The SPC Tornado/Severe Thunderstorm Database. Preprints, 11th Conf. On Applied Climatology, Dallas, AMS (Boston), 215-220.

  4. http://www.spc.noaa.gov/climo

  5. Geographical Distributions25 years of data • Factors for distribution include: • Meteorological factors • Population • Road networks • Spotter networks • Etc. Greenville-Spartanburg, SC Little Rock, Arkansas Milwaukee, Wisconsin Denver, Colorado

  6. March 23rd July 27th Severe Weather SeasonsDefined by objective methods Max 10.5 on 06/09 Average of 2.9 for season • Determine average daily number of severe weather reports • - 7-day running average of all reports (hail, wind, torn) • Any day with value above average meets threshold for season. • Short duration minima are ignored. (5-days or less)

  7. ComparisonsDaily Occurrences & Seasons • St. Louis, Missouri • Season from Mar 29th – Aug 6th • Max of 5.1 on May 28th • Atlanta, Georgia • Season Mar 14th – Aug 4th • Max of 6.7 on May 2nd • Denver, Colorado • Season from Apr 28th – Sep 4th • Max of 4.3 on June 5th • Phoenix, Arizona • Season Jun 28st – Sep 19th ? • Max of 1.2 on Aug 14th

  8. ComparisonsAnnual Occurrences Kansas City, Missouri - Recent increase in hail Pittsburgh, Pennsylvania - Mostly wind reports Hastings, Nebraska - Mostly hail reports Shreveport, Louisiana - Decreasing trend last 10 years

  9. ComparisonsHourly Occurrences Houston, Texas - Severe threat all night • Tallahassee, Florida • Hail and Wind are diurnal • Tornadoes are not • Albany, New York • Rarely severe between 05-14z • - Max threat 21z • Glasgow, Montana • Wind threat lags hail threat • Max threat 02z.

  10. Tornado Strike Probabilities-Return Intervals for any point * Point Probabilities

  11. Rankings – Top 10 Annual Tornado Days Sig. Severe Reports Annual Severe Days Sig. Tornado Reports Sig. Tornado Threat (Annual Avg. Prob.) All Severe Reports

  12. Conclusions • Hopefully useful and informative reference for severe weather distributions across the USA. • Future plan to extend work to county-based CWA areas. • http://www.spc.noaa.gov/climo

More Related