PWO for MDT risk days?

[John Sickels]

pswo

The way the PSWO this morning was written, it looked like something they had written up just-in-case and was accidently sent out prematurely.

 

[Glen Romine]

It looked like an accident to me too - and based on John Hart's comments - it looks like they may have indeed hit the send button by accident - and then had no choice but to make it legitimate and resend a corrected version. Hey, nobody is perfect.

Glen

 

[Andy Wehrle]

The Public Severe Weather Outlooks (PWO) are issued when a potentially significant or widespread tornado outbreak is expected. This plain-language forecast is typically issued 12-24 hours prior to the event and is used to alert NWS field offices and other weather customers concerned with public safety of a rare, dangerous situation. The PWO is reserved for only the most serious weather situations where a HIGH risk is forecast for a potential tornado outbreak.

Well apparently the rules have been changed, because after deleting the initial PSWO they replaced it with a corrected one and did not upgrade to HIGH. They have also changed the wording on their PSWO "header" from

[Broken External Image]:http://sphs.angeltowns.net/images/pwo.gif

The SPC is forecasting an outbreak of severe thunderstorms today and tonight across portions of the United States. THIS IS AN EXTREMELY DANGEROUS SITUATION! Please read the latest public statement about this event.

To:

[Broken External Image]:http://sphs.angeltowns.net/images/pwo.gif

The SPC is forecasting an enhanced risk of severe thunderstorms today and tonight across portions of the United States. Please read the latest public statement about this event.

This does imply the difference in the percieved threat level, but I still think the PSWO should be reserved for those situations where the forecaster is thinking "this will be one for the severe weather history books". We might now see the PSWO become a near-routine product, given that moderate risks are far more common than high risks. While there are many noteable severe weather events that have occured on moderate risk days, most pass without any such major events. This is why I disagree with SPC's decision to once again issue PSWOs without a high risk as they did in the mid 1990s.

 

[Roger Edwards]

Because PWOs were *such* rare products (HIGH risk only, 3-4 times a year) they generally got little notice outside this sort of group (weather weenies who check for them specifically). PWOs were too rare!

Also, the technical SWOs are intended for meteorological guidance, not everybody at large. We get a LOT of feedback questions asking what CAPE means, what "30 NW END...RSL...TOP...25 N MKC" stand for, what is "deep layer shear", etc. Clearly there are a lot of folks trying to use the daily technical outlooks who don't (and shouldn't be expected to) understand them. This screams at the need for more frequent plain language products to convey the severe threat to more taxpayers. Yet we still wanted to reserve the PWO for only a most-critical subset of severe days that could be more dangerous than usual. Therefore...

Last winter I proposed increasing their frequency to all categorical MDTs in order to
1. Provide a plain language outlook (PWO) more often, explaining what the SPC forecasters expect on the days of heightened severe potential -- which are MDT and HIGH categorical risks (lately, 30-40 total/year on average)
2. Increase the visibility of SPC to the media and public through such outlooks.

Consensus among the staff was that it was worth a try, so we went with it -- a little later than hoped because one of the folks involved with software setup was out for a couple of months with medical problems. We also bumped down by one level a few of the probability thresholds for MDT risks. The various pages explaining these things should be updated soon, I hope.

 

[Robert Dewey]

Originally posted by Roger Edwards
Because PWOs were *such* rare products (HIGH risk only, 3-4 times a year) they generally got little notice outside this sort of group (weather weenies who check for them specifically). PWOs were too rare!

Also, the technical SWOs are intended for meteorological guidance, not everybody at large. We get a LOT of feedback questions asking what CAPE means, what \"30 NW END...RSL...TOP...25 N MKC\" stand for, what is \"deep layer shear\", etc. Clearly there are a lot of folks trying to use the daily technical outlooks who don't (and shouldn't be expected to) understand them. This screams at the need for more frequent plain language products to convey the severe threat to more taxpayers. Yet we still wanted to reserve the PWO for only a most-critical subset of severe days that could be more dangerous than usual. Therefore...

Last winter I proposed increasing their frequency to all categorical MDTs in order to
1. Provide a plain language outlook (PWO) more often, explaining what the SPC forecasters expect on the days of heightened severe potential -- which are MDT and HIGH categorical risks (lately, 30-40 total/year on average)
2. Increase the visibility of SPC to the media and public through such outlooks.

Consensus among the staff was that it was worth a try, so we went with it -- a little later than hoped because one of the folks involved with software setup was out for a couple of months with medical problems. We also bumped down by one level a few of the probability thresholds for MDT risks. The various pages explaining these things should be updated soon, I hope.

Sounds very reasonable to me...

There we have it guys, official word from SPC!