Proposed tweaks to severe thunderstorm warnings

The National Weather Service (NWS) is collecting public comment on some proposed changes to severe thunderstorm warnings. These changes would add damage threat labels for wind and hail threats. The three tiers are (no label), considerable, and destructive.

(no label)> 60 mph> 1.0″
Considerable> 70 mph> 1.75″
Destructive> 80 mph> 2.75″

As part of the proposal, the NWS says, they will recommend that destructive severe thunderstorms trigger a wireless emergency alert (WEA) message. This means most modern cell phones will receive an alert for the highest-end storms. According to an analysis by Joseph Patton, this would apply to just over 1% of severe thunderstorm warnings. (This percentage will vary by time and location.)

I am 100% on board with this proposal. Let’s be honest with ourselves: most people ignore severe thunderstorm warnings. I’ll be the first to admit that I do. Once I’m inside, I’m safe enough without taking extra precautions. But those top-end storms can do damage similar to tornadoes. Being able to distinguish between “get inside” and “get to the basement” severe storms is helpful.

Now I’ve suggested before that tornado and severe thunderstorm warnings should be combined into a single product. I still hold that opinion. Intensity of the threat matters more than the specific mechanics of the threat. But I very much doubt the NWS will implement that idea any time soon. This proposal at least allows for cleaner communication of the most life-threatening thunderstorms.

You can give the NWS your own opinion via online survey before July 30, 2020.

Regional weather forecast offices?

Update: The Senate Commerce Committee has amended the bill to remove the regionalization, according to The Washington PostThe bill now focuses on improving how weather hazards are communicated to the public (an effort that is already underway in both the public and private sectors). At the time of this update, it is unclear whether this morning’s post was what convinced Senator Thune to change approaches.


Last week, The Washington Post‘s Capital Weather Gang blog reported on a bill being introduced by the chair of the Senate Commerce Committee. The bill, dubbed “The National Weather Service Improvement Act”, would direct the National Weather Service to consolidate the current 122 weather forecast offices around the country down to six. Although the bill itself is light on details, supporters say it is designed to reduce under-staffing during severe weather outbreaks and it is apparently expected to save money (since the bill has explicit provisions for what is to be done with any savings).

The reactions among my meteorologically-inclined friends were mostly dismissive. Tim Cermak’s thoughts were fairly representative:

Others privately suggested the bill was solely political posturing. No one in Congress would want to be the one to shutter the local NWS office. Still, were the bill to become law, several people expressed concern about the loss of local knowledge.

There are some definite benefits to consolidating forecast responsibilities. Forecast area boundaries lead to discontinuous forecast grids and ugly warning polygons. It stands to reason that fair weather forecasts could be handled at the regional level. But what do the local office forecasters do while they wait for a significant weather event?

If I understand the text of the bill correctly, there are no local forecasters. Only the Warning Coordination Meteorologists would remain at local offices (and presumably electronics technicians to repair radars and other equipment). This would mean the loss of local knowledge which can be key during severe weather events. Local forecasters get to know the locations of small towns in their forecast area better than regional forecasters could. This is important not only for writing warning text, but for contextualizing storm reports.

Ubiquitous broadband Internet has removed some of the need for co- or near-location with data sources such as radars. The ham radio spotter networks would have some trouble, but that could be addressed. One concern I haven’t seen raised is what happens when an office has to take shelter. It’s one thing for an office to hand over responsibilities to surrounding offices for a few minutes as a tornado bears down (or a few hours because phone lines are down). This becomes more difficult (though likely more rare) when suddenly one sixth of the forecast offices drops offline.

Most of the thoughts above are not new. Many of them come from the National Academy of Sciences report upon which the Senate bill is supposedly based. The NAS report has a few key differences, though. Most importantly, it describes regional offices as one of several possibilities (another of which is to retain the status quo). The NAS report also explicitly keeps open local WFOs for hazardous weather, marine, and aviation products. The Senate bill (again, based on my reading) implies that these functions would also be regionalized.

Consolidating forecast operations is not without precedent; the U.S. Navy consolidated its various forecast units in 2011. I could not find any follow-up studies that evaluated a change in effectiveness or forecast accuracy. If any such studies were conducted, they may be classified.

It’s no secret that I’m generally a fan of the National Weather Service. I believe it is a steal for taxpayers. That’s not to say that there is no room for improvement. The NWS must be open to constructive criticism and changes that can improve its ability to perform its mission to protect life and property. This bill does not represent that. I’m not familiar enough with the politics to guess at the driving factor, but it seems to cherry pick from the NAS report without regard for the end result.

Simplifying winter weather products

Decades after the National Weather Service began issuing watches and warnings, many members of the public don’t know what the difference is. When you throw in different products, the confusion only mounts. Too often, the products are based on meteorological distinctions that don’t necessarily mean much to the public. Take, for example, a nor’easter that struck New England in December. Or the confusion around the landfall of Sandy, which became extratropical shortly before landfall.

Some products you might see in a winter event include blizzard, winter storm, high wind, wind chill, ice storm, lake effect snow, and freezing rain. Plus flood products and special weather statements. How should the public try to understand these differences?

In general, I’m a proponent of getting the important information to the consumer as quickly as possible with minimal effort required. This case is an exception. Trying to cram the important information into the headline leads to public confusion and forces forecasters to spend time trying to decide which of a handful of products are correct instead of focusing on communicating impact.

I’m in favor of a smaller set of products, with specific impacts delineated in the text. A “winter storm” and “blizzard” product with watch, warning, and advisory (maybe) levels would go along way toward making the products more clear to the public. Everyone could spend less time thinking about the differences between the products and more time focusing on the impacts and preparedness.

If you’re interested in the official specification for the current suite of winter products, see