Detroit Area tests new Warning Criteria

[Jeff Miller]

Interesting changes coming from Detroit.

Snowfall Warning and Advisory Criteria. Starting this winter season and continuing through at least the ’08-’09 season, NWS Detroit/Pontiac will be running a test, the Snow Intensity Winter Warning Improvement Program (SIWWIP). The idea is to better incorporate snowfall intensity into our warning decisions. However, duration and total snowfall accumulations still need to be accounted. The entire SIWWIP plan is to capture those one or two events every year that drop 4 to 5 inches in about 6 hour time frame. These events are usually more life threatening than a six inch snowfall in 12 hours because the snow falls at a faster rate, and still accumulates to a significant depth. So, during the next two winter seasons the NWS Detroit/Pontiac snow criteria will be...

WARNING 8 inches or more in 24 hours ADVISORY >4 inches but <8 inches in 24 hours
WARNING 7 inches or more in 18 hours ADVISORY >4 inches but <6 inches in 12 hours
WARNING 6 inches or more in 12 hours ADVISORY >2 inches but <4 inches in 6 hours
WARNING 5 inches or more in 9 hours
WARNING 4 inches or more in 6 hours

Opinions?

 

[Robert Dewey]

Yeah, I don't like the new criteria at all... I don't really consider 4 inches in 6 hours to be that significant... or 2-3 inches in 6 hours, for that matter.

Something tells me we'll be seeing quite a few more warnings and advisories this year... but not necessarily more storms

 

[rdale]

The public doesn't know a snow advisory from a winter storm watch from a heavy snow warning... All they know is the accumulation numbers they hear, so whatever criteria DTX uses for issuing warnings is MUCH less important than the specific numbers they use.

And if you've monitored their snowfall forecasts so far this season, well... :>

 

[Robert Dewey]

The public doesn't know a snow advisory from a winter storm watch from a heavy snow warning... All they know is the accumulation numbers they hear, so whatever criteria DTX uses for issuing warnings is MUCH less important than the specific numbers they use.

And if you've monitored their snowfall forecasts so far this season, well... :>

Most people do pay attention to warnings though... since our local TV stations will usually make mention of it.

When most people in the "warning area" only see 3-4 inches... they'll be wondering what's going on, or they'll be thinking it's just another busted forecast. On second thought, I guess that's not really any different than the current public thought

 

[rdale]

Most people do pay attention to warnings though... since our local TV stations will usually make mention of it.

I forgot you're in a non-met TV market...

On second thought, I guess that's not really any different than the current public thought

They're already going b-to-the-wall on this coming event... Not that it's out of the question, but I have WAY too many questions to go on air and telling everyone that southeast Michigan will see a crippling snow event in 3 days

 

[Kenny Drake]

The problem here is NWS uses nation-wide criteria. 2 inches of snow in southern Texas would be the end of the world. 2 inches of snow in the northeast or in the mountains is just another day. Same logic would apply for snowfall rates too. Northern states have the resources to handle pretty extreme snowfall rates while most far southern states have very little resources to deal with any amount of accumulating snow.

 

[rdale]

The NWS does NOT use nationwide criteria for snow events...