NWS-Mt. Holly Winter Storm Warning Map Oddity

[RU848789]

Just noticed this. I always have used the first map, not the second, so I never realized that lower Bucks, Montgomery and Chester had 4" crtieria for a WSWarning and the upper parts of those counties had 6" criteria - I just assumed the entire counties had 6" criteria.  Not the biggest deal in the world, but would think the NWS would only want one of these maps on their site (and I'm presuming the first one is the "official" one).  The maps are accessed from links on different pages, as per below (for some reason American won't let me past the actual 2nd map in).  Anyone from Mt. Holly care to comment? 

 

Also, as an aside, I never understood the rationale for the immediate Philly metro counties to have a 4" criterion and Balt/DC metro counties having a 5" criterion, when the Balt/DC area generally gets less snow.  Anyone?  Bueller? 

 

http://www.erh.noaa.gov/er/phi/WinterMaps/12HourSnowWarningCriteria.gif  (link)

 

http://www.erh.noaa.gov/er/phi/winter.html#Watch/Warning/Advisory%20Criteria  (page w/link)

 

 

 

http://www.erh.noaa.gov/er/phi/images/12-hr-Snow-warni.bmp (2nd map link)

 

http://www.erh.noaa.gov/er/phi/WinterDSS.shtml  (2nd map page with link)

 

 

[famartin]

[famartin]

Just noticed this. I always have used the first map, not the second, so I never realized that lower Bucks, Montgomery and Chester had 4" crtieria for a WSWarning and the upper parts of those counties had 6" criteria - I just assumed the entire counties had 6" criteria.

This was a change done a couple years ago (I wanna say 2012) when they split up the zones (NWS still has a "zone forecast product" and issues long-fuse watches, warnings and advisories by zones).  Formerly, Chester, Montgomery and Bucks counties all each had one "zone"; now they are each split into two zones.

[KamuSnow]

I don't recall when it was changed, but back in the day I seem to remember a "Heavy Snow Warning" for 4" or more whenever there was going to be a significant event. And that covered anything from 4" and up.

[famartin]

I don't recall when it was changed, but back in the day I seem to remember a "Heavy Snow Warning" for 4" or more whenever there was going to be a significant event. And that covered anything from 4" and up.

Back in the day as in the 2000s?   That was an experiment the NWS tried, but abandoned.  We had winter storm warnings before then, and winter storm warnings after.

[KamuSnow]

Back in the day as in the 2000s?   That was an experiment the NWS tried, but abandoned.  We had winter storm warnings before then, and winter storm warnings after.

 

lol, actually I'm thinking way before then, like in the 60's and 70's. Perhaps my memory is fuzzy on this matter

[famartin]

lol, actually I'm thinking way before then, like in the 60's and 70's. Perhaps my memory is fuzzy on this matter

That may have also occurred.  I think we wavered back and forth on this issue a couple of times.

[KamuSnow]

That may have also occurred.  I think we wavered back and forth on this issue a couple of times.

 

I googled it but haven't come up with anything like a history of alerts used over the years.

[snowwors2]

I recall Heavy Snow Warnings very clearly from the 60s/70s...

Those were the days of great anticipation as a young kid

[KamuSnow]

I recall Heavy Snow Warnings very clearly from the 60s/70s...

Those were the days of great anticipation as a young kid

 

Yes indeed!

[RU848789]

This was a change done a couple years ago (I wanna say 2012) when they split up the zones (NWS still has a "zone forecast product" and issues long-fuse watches, warnings and advisories by zones).  Formerly, Chester, Montgomery and Bucks counties all each had one "zone"; now they are each split into two zones.

Gotcha, thanks.  Hopefully, someone from the NWS can "retire" the old graphic. 

 

What do you think about my other comment on what seems like an oddity with the immediate Philly metro counties along the Delaware having only a 4" criterion for a warning, while areas to the SW (Balt/DC area), which get less snow, have a 5" criterion.  Would seem like the Delaware River counties should have a 5" criterion, leaving the NJ shore and southern DE counties with the 4" criterion. 

[RU848789]

Gotcha, thanks.  Hopefully, someone from the NWS can "retire" the old graphic. 

 

What do you think about my other comment on what seems like an oddity with the immediate Philly metro counties along the Delaware having only a 4" criterion for a warning, while areas to the SW (Balt/DC area), which get less snow, have a 5" criterion.  Would seem like the Delaware River counties should have a 5" criterion, leaving the NJ shore and southern DE counties with the 4" criterion. 

 

Was just noodling around their site and noticed that Mt. Holly had finally addressed the oddity I mentioned above, by converting all of their SE PA and South Jersey counties to a 5" of snow winter storm warning criterion in 12 hours, which is consistent with the DC/Balt criterion.  Makes much more sense, although I think one could argue that maybe Cape May and Sussex (DE) should be at 4" to align them with the lower DelMarVa (at least Sussex).  The map, below, is on their winter weather page, captioned, "New Winter Storm Warning Criteria" (caption not on graphic below), but the old map in my first post is still available on their old winter weather page, here:

 

http://www.erh.noaa.gov/er/phi/winter.html#Watch/Warning/Advisory%20Criteria