The NWS will be making changes to the way SPS and SVR products are formated effective tomorrow, August 2nd.
The public will notice these changes when they hear their Weather Radio activate and when they read products from the National Weather Service.
The biggest change will be the addition of a Wireless Emergency Alerts (WEA) activation for Severe Thunderstorm (SVR) products that include the DESTRUCTIVE tag. Additionally, Special Weather Statements (SPS) products will no longer use the “Significant Weather Advisory” text as they will be transitioned to the Impact-Based Warning (IBW) format.
Severe Thunderstorm Warnings
There will be an additional bullet for Thunderstorm Damage Threat at the bottom of each product, where CONSIDERABLE or DESTRUCTIVE can be used – but by default will not be. As stated above, if DESTRUCTIVE is used, it will activate a WEA. Additionally, there will be a HAIL THREAT, MAX HAIL SIZE, WIND THREAT, and MAX WIND GUST tag that can be used.
- The criteria for a destructive damage threat is at least 2.75 inch diameter (baseball-sized) hail and/or 80 mph thunderstorm winds. Warnings with this tag will automatically activate a Wireless Emergency Alert (WEA) on smartphones within the warned area.
- The criteria for a considerable damage threat is at least 1.75 inch diameter (golf ball-sized) hail and/or 70 mph thunderstorm winds. This will not activate a WEA.
- The criteria for a baseline or “base” severe thunderstorm warning remains unchanged, 1.00 inch (quarter-sized) hail and/or 58 mph thunderstorm winds. This will not activate a WEA. When no damage threat tag is present, damage is expected to be at the base level.
The new IPW format will be as follows:
TORNADO…POSSIBLE (if selected)
THUNDERSTORM DAMAGE THREAT…CONSIDERABLE/DESTRUCTIVE (if selected)
HAIL THREAT…RADAR INDICATED/OBSERVED
MAX HAIL SIZE…X.XX IN
WIND THREAT…RADAR INDICATED/OBSERVED
MAX WIND GUST…XX MPH
READ MORE at https://www.weather.gov/news/072221-svr-wea
Special Weather Statements
An example of the new Special Weather Statement format is listed below. As stated above, “Significant Weather Advisory” is no longer used.
Both the National Weather Service in Huntsville and Birmingham will be using this new format starting August 2nd!
Special Weather Statement National Weather Service Quad Cities IA IL 340 PM CDT MON MAY 4 2015 IAZ099-ILZ025-034-MOZ010-042200- Hancock IL-Henderson IL-Lee IA-Clark MO340 PM CDT MON MAY 4 2015 …Strong thunderstorm will impact portions of Hancock, Henderson, Lee, and Clark Counties through 500 PM CDT… At 338 PM CDT, doppler radar was tracking a strong thunderstorm near Keokuk, moving east at 30 mph. HAZARD…40 mph wind gusts and penny size hail. SOURCE…Radar indicated. IMPACT…Minor damage possible to outdoor objects is possible. Locations impacted include… Keokuk, Fort Madison, Carthage, Nauvoo, Niota, Western Illinois University, Hamilton, New Boston, Montrose, St. Francisville, Charleston and Argyle. PRECAUTIONARY/PREPAREDNESS ACTIONS... Frequent cloud to ground lightning is occurring with this storm. lightning can strike 15 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. This storm may intensify, monitor local radio and tv stations, as well as local cable tv outlets, for additional information and possible warnings from the National Weather Service. && LAT...LON 4034 9154 4055 9166 4070 9123 4037 9094 TIME...MOT...LOC 2038Z 259DEG 26KT 4045 9147 MAX HAIL SIZE...0.75 IN MAX WIND GUST...40 MPH
More information and examples at https://nws.weather.gov/products/PDD/Sub_Severe_SPS_Examples.pdf