The IEM maintains an archive of the watch polygons issued by the Storm Prediction Center since 1997. Please note that these watches are not the official spatial bounds anymore as the WCN (watch by county) product is the official coverage.

Related: NWS VTEC Watch Warning Advisory   SPC Convective Discussions   SPC Outlooks   WPC Precip Discussions

Time Interval for Watch *Issuance* (UTC)
YearMonthDay HourMinute
Start:
End:

Download Format

Shapefile DBF schema:

Field 0: Type=C/String, Title=`ISSUE', UTC Issuance Timestamp YYYYmmddHHMM
Field 1: Type=C/String, Title=`EXPIRE', UTC MCD Expiration Timestamp
Field 2: Type=C/String, Title=`SEL', The 0-9 watch sequence number
Field 3: Type=C/String, Title=`TYPE', TOR or SVR watch
Field 4: Type=N/Double, Title=`NUM', SPC Watch Number
Field 5: Type=N/Double, Title=`P_TORTWO', PROB OF 2 OR MORE TORNADOES
Field 6: Type=N/Double, Title=`P_TOREF2', PROB OF 1 OR MORE STRONG /EF2-EF5/ TORNADOES
Field 7: Type=N/Double, Title=`P_WIND10', PROB OF 10 OR MORE SEVERE WIND EVENTS
Field 8: Type=N/Double, Title=`P_WIND65', PROB OF 1 OR MORE WIND EVENTS >= 65 KNOTS 
Field 9: Type=N/Double, Title=`P_HAIL10', PROB OF 10 OR MORE SEVERE HAIL EVENTS
Field 10: Type=N/Double, Title=`P_HAIL2I', PROB OF 1 OR MORE HAIL EVENTS >= 2 INCHES
Field 11: Type=N/Double, Title=`P_HAILWND' PROB OF 6 OR MORE COMBINED SEVERE HAIL/WIND EVENTS
Field 12: Type=N/Double, Title=`MAX_HAIL', MAX HAIL /INCHES/ 
Field 13: Type=N/Double, Title=`MAX_GUST', MAX WIND GUSTS SURFACE /KNOTS/
Field 14: Type=N/Double, Title=`MAX_TOPS', MAX TOPS /X 100 FEET/
Field 15: Type=N/Double, Title=`MV_DRCT', MEAN STORM MOTION VECTOR /DEGREES/
Field 16: Type=N/Double, Title=`MV_SKNT', MEAN STORM MOTION VECTOR /KNOTS/
Field 17: Type=N/Integer, Title=`IS_PDS', PARTICULARLY DANGEROUS SITUATION

Archive / Usage Notes:

  1. 30 April 2022: Associated probabilities found in the WWP product are now included as attributes. This archive goes back to about May 2006.
  2. To re-emphasize, these polygons are not the official watch anymore. The official watch is issued on a county/zone basis.