Blizzard Warning Criteria

[John Diel]

I think I'll chime in here just a bit. I'm not a scientist, but I DO report weather to the General Public. From about 5:00 p.m. to about 8:30 p.m. I was all over Kay County Oklahoma. From early afternoon to after the time I finally got home, we had steady winds of 35 mph with gusts to 40+. Ground visibility was 1/4 mile to 1/2 mile depending on the wind and what was breaking the wind. Blowing snow was the rule. Driving conditions were treacherous at best. From my observations at several points in Kay County, we met the published criteria for a blizzard warning for at least 3/4 of each hour it was in effect.

I also know that the Warning got our attention. We made a concerted effort to get this message out to the public, where as we probably wouldn't have pushed as hard for a Winter Storm Warning or Heavy Snow Warning.

I'm only guessing, but I would bet this was the effect the Warning Coordinator wanted. The Met's at OUN knew what was coming and wanted to make sure the word got out as effectively as possible. With our station, they achieved that goal.

One can argue over the letter of the law all day. However, the word got out and it was generally effective with the exception of the Ponca City Schools. I will be addressing that issue with the Schools on a different tack and not on this forum.

Just my small and un-informed opinion.

John Diel

 

[Mike Umscheid]

While it's nice to 'infer' that vis was < 1/4mi, and I don't disagree with that, the fact remains that the observations don't meet current criteria...

But it's also not just automated surface observations... when it comes to warning decision making like this, first-hand reports have a huge weight in determining what's really going on. When deputies out on the roads are reporting that they can't see about 50 feet in front of them, yet the nearby ASOS ob says "1/4 SM".. and you get a lot of these 50-100 feet visibility reports with 35mph winds and SN or +SN... and if that is ocurring or is expected to occur for 3 hours or more, then that's the NWS definition of a blizzard. We can't just rely on ASOS/AWOS obs, they are only one part of the whole warning and verification process. But I think I'm preaching to the choir, here..

 

[Rick Smith]

Mike raises a good point - looking at only automated surface observations will not always give you an accurate picture of what happened. NWS relies very heavily on human observations to help fill in the gaps, whether we're dealing with winter storms, or convection, or flooding, or high wind events, etc. After all, it is the human that we're issuing the warning for, not a piece of equipment. A report like the one John provides is verification that we had blizzard conditions.

Definitions and guidelines are great, but service and getting the appropriate message out during a critical situation is much more important.

Rick

 

[rdale]

Definitions and guidelines are great, but service and getting the appropriate message out during a critical situation is much more important.

I completely agree, although John's observations do not hit criteria either (no < 1/4mi vis reported.) So if we keep 'bending' the criteria to issue warnings -- wouldn't it make sense to change the criteria so everybody is in sync?

I'm curious - did the warning go anywhere outside of your CWA? If not, is it safe to assume that the other office(s) did not want to "bend" the criteria as much, and there's nothing that causes the public more confusion than a Winter Storm Warning on one side, Heavy Snow Warning on another and a Blizzard Warning to your west. That's why I don't relay any winter weather headlines other than that with the word blizzard - it's just too much to spell out.

But that's yet another topic split ;>

- Rob

 

[John Diel]

Rdale,
Yes, the warning did go over into Tulsa CWA (Osage, Washington and I believe Nowata counties, plus counties in Kansas) and was extended beyond the 9:00 p.m. expiration that Norman had. Maybe I didn't make myself very clear (Duh!). The visibilities on the major roadways in Kay County were less than 1/4 mile most of the time. Not all the time, but most of it. I gaged my visibility on when I could see oncoming traffic and when I could see street lights when available. I did not gage my visibility on the snow reflecting from my headlights. Though that was a BIG factor in my reporting condition to the General Public and made a VERY big difference in travel.

When the immediate visibilities are nil (blowing snow reflecting from headlights and you can't see the sides of the road because of it) but you can see the oncoming traffic headlights 2 or 3 tenths of a mile, it's a tough call. I would also gage my visibility on the vehicle in front of me when available by viewing when I could see the tail lights and when I couldn't.

 

[Robert Rohloff]

Northern Oklahoma

I was out in the storm on Thursday reporting conditions. Having grown up on Michigan, Grand Rapids I have experienced heavy snow and blizzard conditions. In the 25 years I have lived in Tulsa I have not seen it come close to what a true blizzard is. However I was on Hwy 169 in Nowata County, and had sustained visability of under 1/4 mile with heavy snow and blowing and drifting occuring. Many roads were impassable. Had I not been driving an AWD Subaru it would have been real ugly.

I do believe that near the Kansas state line the blizzard conditions were met. I also feel the warning helped keep people off the road since there was very few people out at all.