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.
Backend DocumentationRelated Services
Shapefile DBF Schema
| Field | Type | Title | Description |
|---|---|---|---|
| 0 | String | ISSUE | UTC Issuance Timestamp YYYYmmddHHMM |
| 1 | String | EXPIRE | UTC MCD Expiration Timestamp |
| 2 | String | SEL | The 0-9 watch sequence number |
| 3 | String | TYPE | TOR or SVR watch |
| 4 | Double | NUM | SPC Watch Number |
| 5 | Double | P_TORTWO | PROB OF 2 OR MORE TORNADOES |
| 6 | Double | P_TOREF2 | PROB OF 1 OR MORE STRONG /EF2-EF5/ TORNADOES |
| 7 | Double | P_WIND10 | PROB OF 10 OR MORE SEVERE WIND EVENTS |
| 8 | Double | P_WIND65 | PROB OF 1 OR MORE WIND EVENTS >= 65 KNOTS |
| 9 | Double | P_HAIL10 | PROB OF 10 OR MORE SEVERE HAIL EVENTS |
| 10 | Double | P_HAIL2I | PROB OF 1 OR MORE HAIL EVENTS >= 2 INCHES |
| 11 | Double | P_HAILWND | PROB OF 6 OR MORE COMBINED SEVERE HAIL/WIND EVENTS |
| 12 | Double | MAX_HAIL | MAX HAIL /INCHES/ |
| 13 | Double | MAX_GUST | MAX WIND GUSTS SURFACE /KNOTS/ |
| 14 | Double | MAX_TOPS | MAX TOPS /X 100 FEET/ |
| 15 | Double | MV_DRCT | MEAN STORM MOTION VECTOR /DEGREES/ |
| 16 | Double | MV_SKNT | MEAN STORM MOTION VECTOR /KNOTS/ |
| 17 | Integer | IS_PDS | PARTICULARLY DANGEROUS SITUATION |
Archive / Usage Notes
30 April 2022: Associated probabilities found in the
WWP
product are now included as attributes. This archive goes back to about May 2006.
Important: To re-emphasize, these polygons are not the official
watch anymore. The official watch is issued on a county/zone basis.