Is the NWS redefining their winter weather warnings?

[aerojad]

Here in Detroit we are under a Heavy Snow warning for the second storm in a row - with a predicted 5 - 9 inches to fall across most of the area, much like the last storm (except this is wet and heavy ). Anyhow, I can never, ever recall being under a Heavy Snow warning, and up until last year, storms that brought 6+" of snow were usually the domain of Winter Storm Warnings. Is the NWS trying to refine their message when it comes to the names of warnings, and now Winter Storm Warning is a level above Heavy Snow Warning?

[jkt21787]

A winter storm warning means that IN ADDITION to heavy snowfall amounts, that strong wind gusts, low wind chills, and reduced visbility from blowing/drifting snow can also be expected. A heavy snow warning means that there will just be heavy snow, not so much wind, wind chills, and low visibilities.

[Brent]

There was a Heavy Snow Warning down here during the Blizzard of 1993(our criteria is much less though since snow is more rare).

NWS Birmingham criteria:

A "Winter Storm Warning" is issued when a combination of hazardous winter weather is occurring, is imminent, or is expected. Winter Storm Warnings are issued when one or more of the following is expected:
· Snowfall of 2+ inches in 12 hours
· Accumulation of freezing rain (ice) greater than 0.05".
· Accumulation of sleet (ice pellets) greater than 0.50".

· Heavy Snow Warning (WSW)
A "Heavy Snow Warning" is issued when snowfall of 2+ inches in 12 hours. If strong winds and low wind chills are expected in addition to the heavy snow, then a Winter Storm Warning or Blizzard Warning will be issued instead.

[terstorm1012]

Each office has its own critieria. A Winter Storm Warning down in Dallas is way different then a Winter Storm Warning up here in PA--usually their winter storm warnings get us winter weather advisories - if even.

[aerojad]

Ahh, thank you both. Up until last year the Detroit office has just been using Winter Storm Warnings for any signifigant snow event aove 6"+, winds or not. So I guess this is a local office or regional clarification.

[jkt21787]

Each office has its own critieria. A Winter Storm Warning down in Dallas is way different then a Winter Storm Warning up here in PA--usually their winter storm warnings get us winter weather advisories - if even.

There are accumulation differences, but the basis for winter storm vs. heavy snow warning is the same: Winter Storm includes strong winds, low wind chills, reduced visbility or also could be issued if sleet or freezing rain is anticipated in addition to snow. Heavy snow warning is snowfall amounts that exceed local warning criteria, but there won't be any of the above mentioned conditions in addition to the heavy snow.

[Brent]

Each office has its own critieria. A Winter Storm Warning down in Dallas is way different then a Winter Storm Warning up here in PA--usually their winter storm warnings get us winter weather advisories - if even.

We can get an advisory for 1/4 inch of snow...

[jkt21787]

Each office has its own critieria. A Winter Storm Warning down in Dallas is way different then a Winter Storm Warning up here in PA--usually their winter storm warnings get us winter weather advisories - if even.

We can get an advisory for 1/4 inch of snow...

I noticed that when looking up criteria. That is even laughable here in Memphis.

You also get a winter storm WARNING for 0.05" of ice. 5 hundreths of an inch! That is pretty pathetic, honestly.

[Lowpressure]

Each office has its own critieria. A Winter Storm Warning down in Dallas is way different then a Winter Storm Warning up here in PA--usually their winter storm warnings get us winter weather advisories - if even.

There are accumulation differences, but the basis for winter storm vs. heavy snow warning is the same: Winter Storm includes strong winds, low wind chills, reduced visbility or also could be issued if sleet or freezing rain is anticipated in addition to snow. Heavy snow warning is snowfall amounts that exceed local warning criteria, but there won't be any of the above mentioned conditions in addition to the heavy snow.

True as an example- LWX goes WSW at 4.5 inches of snow.

[wxwatcher91]

WINTER STORM WARNING
When the following expected in the next 24-36 hours:
1/2 inch accretion of freezing rain in any zone
Snow or snow and sleet combination:
6 inches averaged over a forecast zone in 12 hours
8 inches averaged over a CT, MA, RI forecast zone in 24 hours.
9 inches averaged over a NH forecast zone in 24 hours


BLIZZARD WARNING
At least 3 hours, falling and/or blowing snow frequently reduces visibility to < 1/4 mile AND sustained winds or frequent gusts >= 35 mph

[WindRunner]

LWX definitions:

Winter Storm Warning

A winter storm warning is issued when significant and hazardous winter weather is occurring or imminent.

Significant and hazardous winter weather is defined as:
1) Over 4 inches of snow (and/or sleet).
OR
2) Glaze accumulation (freezing rain) of 1/4 inch or more
OR
3) Enough ice accumulation to cause damage to trees or powerlines.
OR
4) a life threatening or damaging combination of snow and/or ice
accumulation with wind.

Winter Weather Advisory

A winter weather advisory is issued when snow, sleet, freezing rain, or
a combination of precipitation types is expected to cause a significant
inconvenience but not serious enough to warrant a warning.

A winter weather advisory is issued when one or more of the following
conditions are met:

1) 2 inches of snow east of a line from Frederick Maryland to
Charlottesville Virginia
3 inches of snow west of a line from Frederick Maryland to
Charlottesville Virginia.
OR
2) For freezing rain or freezing drizzle, you issue the advisory when
any accumulation of glaze is expected on streets or sidewalks.


Interestingly enough they have no definition for a Heavy Snow or Ice Storm warning, guess those are a little newer. I can't ever remember having an ice storm warning here. Funny thing is that in NY state they are forecast to get 5-9" and have only an advisory up. All products are definately area dependent, not just winter weather ones.

[Tri-State_1925]

Here in Detroit we are under a Heavy Snow warning for the second storm in a row - with a predicted 5 - 9 inches to fall across most of the area, much like the last storm (except this is wet and heavy ). Anyhow, I can never, ever recall being under a Heavy Snow warning, and up until last year, storms that brought 6+" of snow were usually the domain of Winter Storm Warnings. Is the NWS trying to refine their message when it comes to the names of warnings, and now Winter Storm Warning is a level above Heavy Snow Warning?

I said the same thing last year when we had a Heavy Snow Warning. That was the first time I had heard of it. Apparently it has been around for a while, but until last year I had NEVER seen one issued for my parts of New England. Only the Winter Storm and Blizzard Warnings were used. I think the NWS started using the Heavy Snow Warning more liberally last year.

[aerojad]

Good, I'm not the only one to notice